How to Open a Battery
A battery is open when its plates have been drawn out of
the hard rubber jars. All parts are then exposed, and accessible
for inspection and repairs. In an assembled battery, the top of
each cell is closed by a hard rubber cover. Leakproof joints are
made between these covers and the rubber jars and the wooden case
by means of sealing compound which is poured in place while in a
molten condition, and joins the covers to the jars and which
hardens as it cools. The joints between the covers and the posts
which project through the covers are in many batteries made with
sealing compound. The cells are then connected to each other by
means of the cell connectors, also called "top-connectors," or
simply "connectors." These connectors are joined to the lead
posts, to which are connected the plate groups by fusing with a
flame, and melting in additional lead to make a joint.
In opening a battery, we must first disconnect the cells from
each other, and then open the joint made by the sealing compound
between the covers and the jars and case. The plates may then be
lifted out of the jars, and the battery is open. The steps
necessary to open a battery follow, in the order in which they
must be taken.
1. Clean the Battery. Set the
battery on the tear down rack. See that the vent plugs are all
tight in place. Then clean the outside of the battery. Remove the
greater part of the dirt with a brush, old whisk-broom, or a putty
knife. Then put the battery in the water, using a stiff bristled
brush to remove whatever dirt was not removed in the first place.
A four-inch paint brush is satisfactory for this work, and will
last a year or more if taken care of. If water will not remove all
the dirt, try a rag wet with gasoline.
2. Drilling Off the Connectors
and Terminals. When you have cleaned the outside of the
battery as thoroughly as possible, set the battery on the floor
near your work bench. Make a sketch of the top of the battery,
showing the exact arrangement of the terminals and connectors.
This sketch should be made on the tag -which is tied to the
battery. Tic this tag on the handle near the negative terminal of
the battery or tack it to the ease. Then drill down over the
Center of the posts. For this you will need a large brace with a
heavy chuck, a drill the same size as the post (the part that goes
down into the battery), a large screw driver, a center punch, and
a hammer.
With the center punch, mark the exact centers of the tops
of the posts and connectors. Then drill down about half way
through the connectors and terminals until you cut through the
part of the connector which is welded to the post. When you can
see a seam between the post and connector you have drilled through
the welded part. See Figs. 191 and 192.
Now pry off the connectors with the screw driver, as shown in
Fig. 193. Lay a flat tool such as a chisel or file on the top edge
of the ease to avoid damaging the ease when prying off the
connectors.
If any connector is still tight, and you cannot pry it off with
a reasonable effort, drill down a little deeper, and it -will come
off easily, provided that the hole which you are drilling is
exactly over the center of the post and as large as the post.
There are five things to remember in drilling the connectors and
posts:
(a) Be sure that the hole is exactly over the center
of the post.
(b) Do not drill too deep. Make each hole just deep enough
so that the connector will come off easily. Fig. 192 shows a
cross section of a post and connector drilled to the proper
depth. Notice that you need not drill down the whole depth of
the connector, because the bottom part is not burned to the
post.
(c) Be sure that the drill makes the right sized hole to
permit the connectors and terminals to be removed easily when
drilled half way through. An electric drill will do the work
much faster than a hand brace.
(d) Protect the edge of the battery box when you pry up the
connectors with a screw driver.
(e) Remove your drill after the hole is well started and see
whether the hole is in the center of the post. Should you find
that it is off center, tilt the drill, and with the end of the
drill pointing the center of the post as you drill, gradually
straighten the drill. This will bring the hole over the center
of the post.
Having removed the connectors, sweep all the lead
drillings front the top of the battery into a box kept for lead
drillings only. Fig. 194. When this box is full, melt the
drillings and pour off in the burning lead mould.
Post Seal. If the post seal
consists of a lead sealing nut, this may be removed now. With some
types of batteries (Willard and U. S. L.), drilling the connectors
also breaks the post seal. With other batteries, such as the
Vesta, Westinghouse, Prest-0-Lite, Universal, it is more difficult
to break the post seal. On these batteries, therefore, do not
break this seal before drawing out the plates. You may find that
it will not be necessary to separate the groups, and the post seal
will not have to be broken at all, thereby saving yourself
considerable time on the overhauling
job.
| 3. Heating Up the Sealing Compound. Having
disconnected the cells from each other by removing the
cell connectors, the next step is to open the joint made
by the sealing compound between the covers and jars. Fig.
195 shows the battery ready for this step. When cold, the
compound is a tough substance that sticks to the cover
and jar, and hence it must be heated until it is so soft
that it is easily removed. There are several methods by
means of which compound may be heated. These are as
follows: |
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Steam. This is the most popular, and
undoubtedly the best means of heating the compound, and in the
following instructions it will be assumed that steam has been
used. The battery is either placed in a special box in which steam
is sent, or else steam is sent directly into each cell through the
vent tube. In the first method the compound is heated from the
outside, and in the second it is heated from the inside of the
cell.
If the battery is placed in the steaming box, about ten minutes
will be required for the steam to heat up the sealing compound.
For batteries which use but very little compound, less time is
required. if steam is sent directly into the cells through the
vent tubes, five to seven minutes will generally be enough. The
covers must be limp and the 1 compound must be soft before turning
off the steam.
Hot Water. The electrolyte is
poured out of the battery, which is then inverted in a vessel of
hot water. This method is slower than the others, and is more
expensive because it requires a larger volume of water to be
heated.
Hot Putty Knife and
Screwdriver. The compound may be dug out with a hot putty
knife. This is a slow, unsatisfactory method in most instances,
especially in those batteries which use a considerable amount of
sealing compound. With some batteries using only a small quantity
of compound, a heated putty knife may be run around the inside of
the jar between the jar and the cover. This will break the joint
between the cover and the jar, and allow the plates to be lifted
out. The compound is then scraped from covers and inside of jars,
heating the knife or screwdriver whenever it cools off.
Lead Burning Flame.
Any soft lead burning flame may be used. Such a flame may be
adjusted to any desired size. Where steam is available, a flame
should, however, never be used. The temperature of the flame is
very high, and the covers, jars, case, posts, and vent plugs may
be burned and made worthless. Even for the expert repairman, a
flame is not as satisfactory as steam.
The Gasoline Torch.
This is the most unsatisfactory method, and should not be used
if possible. The torch gives a hot, spreading flame and it is
difficult to prevent the covers, jars, case, etc., from being
burned. Do not use a gasoline torch if you can possibly avoid
doing so. Alcohol torches are open to the same objections, and are
not satisfactory, even in the hands of a highly skilled
workman.
If a flame is used for heating the compound, be sure to blow
out with a hand bellows or compressed air any gas that may have
gathered above the plates, before you bring the flame near the
battery.
Electric Heat. Special
electric ovens for softening sealing compound are on the market.
The heating element is brought close to the top of the battery.
Where electric power is cheap, this method may be used. Otherwise
it is rather expensive.
When the sealing compound
has been softened, place the battery on the floor between your
feet. Grasp the two posts of one cell with pliers, and pull
straight up with an even, steady pull. If the battery has been
steamed long enough, the plates will come up easily, carrying with
them the cover (or covers, if the batter has upper and lower
covers) to which the compound is sticking, as shown in Fig. 196.
Do not remove the plates of the other cells until later.
Rest the plates on the top of the jar just long enough to
allow most of the acid to drain from them, Fig. 197. If you have
removed the post seal, or if the seal consists of compound (old
Philadelphia batteries), pry off the covers now with a screw
driver. Otherwise, leave the covers in place while cleaning off
the compound.
While the plates are resting on the jars
to drain, scrape the compound from the covers with a warm screw
driver or putty knife, Fig. 198. Work quickly -while the compound
is still hot and soft, and comes off easily. As the compound cools
it hardens and sticks to the covers and is removed with
difficulty. If the battery has sealing compound around the posts,
this should also be removed thoroughly, both from the cover and
from the post.
When you scrape the compound from the covers, do a good
job. Do not scrape off most of it, and then leave pieces of it
here and there. Remove every bit of compound, on the tops, edges,
sides, and bottoms of the covers. If you need different sized
putty knives or screw drivers to do this, use them. The time to
remove all the compound is -while it is still hot, and not after
it has become hard and cold. If the battery has single covers, the
compound can be removed very quickly. If the battery is of the old
double-cover type, the job will take more time, since all the
compound should be scraped from both top and bottom covers, Fig.
199.
As soon as you have removed the compound from the covers of the
first cell, serape away the compound which may be sticking to the
top and inside walls of the jar, Fig. 200. Here again you must do
a good job, and remove all of this compound. If you do not do it
now, you will have to do it when you try to put the plates back
into the jar later on, as compound sticking to the inside walls of
the jar will make it difficult, and even impossible to lower the
plates into the jar.
Now draw up the plates of the next cell. Rest the plates on the
top of the jar just long enough to drain, and then lift off the
covers, and remove all of the compound, from cover, posts, and
jar, just as you did in the first cell. The third cell, (and the
others, if there are more than three cells) are handled just as
you did the first one.
Remember that you should lose no time after you have steamed
the battery. Hot compound is soft. and does not stick to the
covers, jars, and posts and may therefore be removed quickly and
easily. Cold compound is hard, and sticks to the covers. Draw out
the plates of only one cell at a time, and clean the compound from
the cover, posts and jar of that one cell before you draw out the
plates of the other cells. In this way, the compound on the covers
of the other cells will remain hotter than if all the plates of
the battery were drawn out of the jars before any of the compound
was removed from the covers. You should have all the plates drawn
out, and all the compound removed within five minutes after you
draw up the plates,
Throw away the old compound. If is very likely
acid-soaked and not fit for further use.
What Must Be
Done with the Battery?
The battery is now open, and in a condition to be
examined and judgment pronounced upon it. The question now arises,
"What must be done with it!" In deciding upon this, be honest with
your customer, put yourself in his place, and do just what you
would like to have him do if he were the repairman and you the car
owner. The best battery men occasionally make mistakes in their
diagnosis of the battery's condition, and the repairs necessary.
Experience is the best teacher in this respect, and you will in
time learn to analyze the condition of a battery quickly.
Handle every cell of a battery that comes in for repairs in
the same way, even though only one dead cell is found, and the
others are apparently in good condition. Each cell must be
overhauled, for all cells are of the same age, and the active
materials are in about the same condition in all the cells, and
one cell just happened to give out before the others. If you
overhaul only the dead cell, the others cells are quite likely to
give out soon after the battery is put into service again.
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It is absolutely necessary for you to have
a standard method in working on battery plates. You
must divide your work into a number of definite steps,
and always perform these steps, and in the same order
each time. If you have a different method of
procedure for every battery, you will never be
successful. Without a definite, tangible method of
procedure for your work you will be working in the
dark, and groping around like a blind man, never
becoming a battery expert, never knowing why you did a
certain thing, never gaining confidence in yourself.
It is impossible to overemphasize the importance of
having a standard method of procedure and to
stick to that method. Careless, slip-shod methods will
please your competitor and give him the business which
belongs to you.
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1. Examine plates to determine whether they can be used again
Rules for determining when to discard or use old plates
follow.
2. If all plates of both positive and negative groups are to be
discarded, use new groups.
The question as to whether the old negatives should be used
with new positives has caused considerable discussion. If the
negatives are old and granulated, they should of course be
discarded. Remember that the capacity of negatives decreases
steadily after they are put into service, while the capacity of
positives increases. Putting new positives against negatives which
are rapidly losing capacity is not advisable. However, trouble
often arises in a battery whose negatives still have considerable
capacity, and such negatives may safely be used with new
positives.
If you feel that a battery will not give at least six months'
more service after rebuilding with the old negatives, put in all
new plates, or sell the owner a new battery, allowing him some
money on the old battery. But if you really believe that the
negatives still have considerable capacity, put in new positives
if required. If all new plates are used, proceed as directed in
this chapter, beginning at page 348.
3. If you find that only some of the plates are to be
discarded, or if you are not certain as to the condition of the
plates, eliminate any short circuits which may exist, and give the
battery a preliminary charge, as described later, before you do
any work on the plates. Plates that are fully charged are in the
best possible condition for handling, and you should make it an
ironclad rule that if some of the plates can be used again
always to charge a battery before you work on the plates, no
matter what is to be done to them. If both positives and
negatives are to be discarded, the preliminary charge should not,
of course, be given, but if only the negatives, or the negatives
and some or all of the positives are to be used again, give this
preliminary charge. Very few batteries will come to your shop in a
charged condition, and an exhausted battery is not in a good
condition to be worked on. Charge the whole battery even though
only one cell is in a very bad condition. This is a method that
has been tried out thoroughly in practice, not in one or two
cases, but in thousands. Batteries in all sorts of conditions
have been rebuilt by this method, and have always given first
class service, a service which was frequently as good, if not
better than that given by new batteries.
Place an element on a block of wood as shown in Fig. 201.
Carefully pry the plates apart so that you can look down between
them and make a fair preliminary examination. Whenever possible,
make your examination of the plates without separating the groups
or removing the old separators. This should be done because:
(a) Very often the active material is bulged or swollen, and if
you pull out the old separators and put in new ones before
charging, the element spreads out so at the bottom that it cannot
be put back into the jars without first pressing in a plate press.
Pressing a complete element with the separators in place should
never be done if it can possibly be avoided. If it is done the
separators should be thrown. away after you have charged the
battery, washed and pressed the negatives, and washed the
positive.
(b) If you put in new separators before giving the battery the
preliminary charge, the new separators may pick up any impurities
which may be on the plates, and will probably be cracked by
forcing them- between the bulged and sulphated plates. If,
however, the old separators are covered with sulphate, it is best
to throw them away and put in new separators before giving the
battery its preliminary charge, because such separators will
greatly hinder the flow of the charging current. In batteries
using rubber sheets in addition to the wooden separators, remove
all the wooden separators and leave the rubber sheets in place
between the plates. Where only wooden separators are used in a
battery, these may be thrown away and perforated rubber separators
used for the preliminary charge. Rubber separators may be used
again. See (a) above about precautions against pressing a complete
element.
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If you are not absolutely certain as to the
condition of the plates, draw out a few separators. If
separators stick to the plates, loosen them by inserting
a putty knife blade between them and the plates. Removing
a few separators will permit you to separate the groups
before removing the rest of the separators. To separate
the groups, grasp a post in each hand, as, in Fig. 202,
and work them back and forth, being careful not to injure
the posts, or break off any plates. With the groups
separated, the remaining separators will either fall out
or may be easily pushed out with a putty knife.
Ordinarily, the groups may be separated in this way if
the elements have thirteen plates or less.
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The natural thing to do at this point is to decide what
must be done to the plates, and we therefore give a number of
rules to help you determine which are to be junked, and which are
to be used again. Study these rules carefully, and have them fixed
firmly in your mind so that you can tell instantly what must be
done with the plates.
When to Put In
New Plates
1. If one or more jars are cracked and leak, and
positive plates have been ruined by freezing, as shown in Fig.
203, and if upon drawing out the separators, and separating the
positive and negative groups the active material drops out of the
grids, the only way to put the battery in a good condition is to
put in 'new positives, and new jars and case if necessary.
Make a careful estimate of
(a) Cost of new jars.
(b) Cost of new plates.
(c) Cost of new case if needed.
(d) Cost of labor required.
Try to have the owner present while you are opening his
battery. If, however, he could not wait, and has left, call him up
and tell him what the total cost will be, and if he has no
objections, go ahead with the job. If he is not entirely satisfied
with your price, try to get him to come to your shop. Show him the
battery, explain its condition, tell him just what must be done
with it, and explain how you made your estimate of the cost of the
whole job. If you do this. there will never be any
misunderstanding as to cost. Tell him the cost of a new battery,
and let him decide if lie wants one. If the cost of repairing is
almost as much as the price of a new battery. advise him to buy a
new one, but allow him to make the decision himself. He will then
have no cause for complaint.
| Fig. 204 and 205, Show Diseased Negatives. The Large Ones
Only Eight Months Old. Active Material, Granulated and
Blistered. |
2. If the battery is more than two years old, and
the active material on the negative plates is granulated (grainy
appearance), Figs. 204 and 205, and somewhat disintegrated; if the
plates are weak and brittle around the edges, and several grids
are cracked, Fig. 206, and the plates have lost a considerable
amount of active material; and if the case has been rotted by the
acid, the battery should be junked.
Call up the owner, and tell him he needs a new battery.
If he does not seem pleased, ask him to come to your shop. Then
show him his battery, and explain its condition. If you are
courteous and patient, you will sell him a new battery. Otherwise
he will never return.
3. If the positive plates are badly distorted from
buckling, as in Figs. 207 and 208 discard them, for they will
cut through new separators, if put into commission again, ill from
two to six months.
4. A battery which has has been dry and badly sulphated
at some past period of its life will have tile dry portion.",
covered with a white sulphate, tile acid line being clearly
distinguishable by this white color, as shown at A and B in Fig.
201. If the plates are otherwise ill good shape and you wish to
use them, give them the "water cure" described on page 349.
5. Rotten and
disintegrated positive plates, Figs. 209 and 210, must be
replaced with new plates. The plates have fallen to pieces or
break at the slightest pressure. Disintegrated plates are an
indication of impurities or overcharging, providing the battery is
not old enough to cause disintegration normally,--say about two
years. The lead grid is converted into peroxide of lead and
becomes soft. As a result, there is nothing to support the paste,
and it falls out. Better put in new negatives also.
6. Batteries with high gravity or hot electrolyte have
burned and carbonized separators, turning them black and rotting
them, the negative paste becomes granulated and is kept in a soft
condition, and gradually drops from the grids on account of the
jolting of the car on the road. Fig. 211 shows such a battery.
7. Dry, hard, and
white, long discharged, and badly sulphated plates, Figs. 201
and 209, are practically ruined, though if the trouble is not of
long standing, the plates may be revived somewhat by a long charge
at a very low rate, using distilled water in place of the
electrolyte, and then discharging at a current equal to about
one-eight to one-tenth of the ampere hour capacity of the battery
at the discharge board. Charge and discharge a battery a number or
times, and you may be able to put a little "pep" into it. In
charging sulphated plates, use a low charging rate, and do not
allow gassing before the end of the charge, or a temperature of
the electrolyte above 110°F.
8. If a battery case is not held down firmly, or
if the elements are loose in the jars, the plates will jump around
when the car is in motion. This will break the sealing compound on
top of the battery, and cause the battery to be a slopper. The
active materials will be shaken out of the grids, as shown in Fig.
212, and the plates will wear through the separators. New plates
are required.
9. If Battery Has Been
Reversed. Often the plates of such 'a battery disintegrate and
crumble under the slightest pressure. If the reversal is not too
far advanced, the plates may be restored (See page 81), but
otherwise they should be discarded. This condition is recognized
by the original negatives being brown, and the original positives
gray.
From. the foregoing explanations, you see that most of the
trouble is with the positives:
(a) Because the positive active material does not
stick together well, but drops off, or sheds easily.
(b) Because the positives warp or buckle, this causing most
of the battery troubles.
(c) Because the positive plate is weaker and is ruined by
freezing.
When the
Old Plates May be Used Again
1. If one or more plates are broken from the plate
connecting straps, or the joint between any strap and the
plate is poorly made. If plates are in good condition, reburn the
plate lugs to the straps.
| Fig. 212. Element from a "Slopper." Element was Loose
in Jar. and Jolting of Car Caused Paste to Fall Out |
2. Straight Rebuild. If the general condition
of the battery is good, i.e., the plates straight or only slightly
buckled. only a slight amount of shedding of active material, no
white sulphate oil either plate, the grids not brittle. active
material adhering to and firmly touching the grids. the positive
active material of a dark chocolate brown color and fairly hard
(as determined by scratching with blade of a pocket knife), tile
negative active Material dark gray in color and not blistered or
granulated, and tile plates not too thin, make a straight rebuild.
To do this, charge the battery. remove any sediment from the
bottom of the jar, wash and press the negatives, wash the
positives, clean the parts, insert new separators, and reassemble
as directed later. The only trouble may be cracked sealing
compound, or a broken jar. Broken jars should, of course, be
replaced.
3. "Badly bulged negative plates, Fig. 213, cause
lack of capacity because the active material is loose, and does
not make good contact with the grids. If the active material is
not badly granulated (having a grainy appearance) the plates call
be used again. Sulphated negatives have very hard active material,
and will feel as bard as stone when scratched with a knife. Hard
negatives from Which active material has been falling ill lumps
Oil account of being overdischarged after having been in in
undercharged condition may be nursed back to life, if too much of
the active material has not been lost.
4. The formation of an excessive amount of sulphate may
result in cracking the grids, and the active materials falls out
in lumps. Such plates may be put in a serviceable condition by a
long charge and several cycles of charge and discharge if there is
not too much cracking or too much loss of active material.
5. Positives which are only slightly warped or buckled
may be used again.
6. When the only trouble found is a slight amount of
shedding. Positive active material must be of a dark chocolate
brown color and fairly hard. Negatives must be a dark gray.
7. When the plates are in a good condition, but one or more
separators have been worn or out through, or a jar is
cracked.
If the battery is one which will not hold its charge, and
plates seem to be in a good condition, the trouble is very likely
caused by the separators approaching the breaking down point, and
the repair job consists of putting in new separators or
"reinsulating" the battery.
What To Do With the
Separators
It is the safest plan to put in new separators whenever a
battery is opened, and the groups separated. Separators are the
weakest part of the battery, and it is absolutely essential that
all their pores be fully opened so as to allow free passing of
electrolyte through them. Some of the conditions requiring new
separators are:
1. Whenever the pores are closed by any foreign matter
whatsoever. Put in new separators whether you can figure out the
cause of the trouble or not. The separator shown in Fig. 201 is
sulphated clear through above the line B, and is worthless. The
separator shown in Fig. 203 should not be used again.
| Fig. 214. Separators Worn Thin and Cut Through on
Edges by Buckled Plates. Holes Worn Trhough by Bulged
Active Material, Center One Shows Cell Was Dry Two Thirds
of the Way Down. |
2. When the separators have been cut or "chiseled
off" by the edge of a buckled plate, Fig. 214.
3. When a buckling plate or plate with bulged active
material breaks through the separator, Fig. 214.
4. When a battery has been used while the level of
the Fig. 214. Separators Worn Thin and Cut Through on Edges by
Buckled Plates. Holes Worn Through by Bulged Active Material.
Center One Shows Cell Was Dry Two Thirds of the Way Down
electrolyte has been below the tops of the plates, or the battery
has been used in a discharged condition, and lead sulphate has
deposited on the separators, Fig. 201.
5. When a battery has been over-heated by overcharging
or other causes, and the hot acid has rotted, burned and
carbonized the separators, Fig. 215.
6. When a battery has been damaged by the addition of
acid and the separators have been rotted, Fig. 215.
7. Separators which are more than a year old should be
replaced by new ones, whether plates are defective or
not.
When you have put in new separators, and put the
battery on charge, the specific gravity of the
electrolyte may go down at first, instead of rising. This
is because the separators may absorb some of the acid. If
the battery was discharged when you put in the new
separators, the lowering of the specific gravity might
not take place, but in most cases the specific gravity
will go down, or not change at all.
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Find the Cause of Every Trouble
The foregoing rules must be studied carefully and
be clearly tabulated in your mind to be able to tell what to put
into commission again and what to discard as junk. It will take
time to learn how to discriminate, but keep at it persistently and
persevere, and as you pass judgment on this battery and that
battery, ask yourself such questions as: What put this battery in
this condition? Why are the negative plates granulated? Why are
the positive plates buckled? What caused the positive plates to
disintegrate? Why are the separators black? Why is the case rotten
when less than a year old? Why did the sealing compound crack on
top and cause the electrolyte to slop? Why did one of the terminal
connectors get loose and make a slopper? Who is to blame for it,
the car manufacturer, the manufacturer of the battery, or the
owner of the car? Why did this battery have to be taken off the
car, opened up and rebuilt at 5 months old, when the battery taken
off a car just the day before had been on for 30 months and never
had been charged off the car but once? There is a reason;
find it. Locate the cause of the trouble if
possible, remove the cause; your customer will
appreciate it and tell his friends about it, and this will mean
more business for you.
If you have decided that some or all of the plates may be
used again, the next thing to do is to separate any plates that
are touching, and put the battery on charge. It may be necessary
to put in new separators in place of the defective ones. Examine
the separators carefully. Whenever you find the pores of the
separators stopped up from any cause whatsoever, put in new
separators before charging.
1. Sometimes the negative plates are bulged or blistered badly
and have worn clear through the separators, Fig. 214, and touch
the positives. In cases of this kind, to save time and trouble,
separate the groups, press the negatives lightly, as described
later, assemble the element with new separators, and it is ready
for charging.
2. There is another case where the groups must be separated and
new separators inserted before they will take charge, and that is
where the battery has suffered from lack of water and has
sulphated clear through the separators, Fig. 201. The separators
will be covered with white sulphate. Chemical action is very
sluggish in such cases.
If you find. that the separator pores are still open, leave the
separators in place and proceed to separate the plates that are
touching. How? That depends on what insulating material you have
available that is thin enough. If nothing else is available, take
a piece of new dry separator about 3/8 inch to 1/2 inch square, or
a piece of pasteboard the same size. Use a screw driver or putty
knife to separate the plates far enough to insert the little piece
of insulation as in Fig. 216. Free all the shorts in this way,
unless you have some old rubber insulators. In this case, break
off some narrow strips 3/4 inch wide or less, put two together and
repeat the operation as above, using the rubber strips instead of
the pieces of separator. Insert down 1/2 inch or so and bend over
and break off. Occasionally the Lipper edges of the plates are
shorted, in which case they must be treated the same
way.
When you have in this way cleared all the "shorts" in the
elements place the elements back in the jars in the same position
as they were when you opened the battery, and add enough distilled
water to the electrolyte to cover the plates to a depth of
one-half inch.
If the negatives are badly sulphated (active material very
hard), they will charge more quickly if all the old electrolyte is
dumped out and the cells filled with distilled water before
putting the battery on charge. This "water cure" is the best for
sulphated negatives and will save many plates that could otherwise
not be used again. Make it a rule to replace the old electrolyte
with distilled water if negatives are sulphated.
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Fig. 218. Tapping Connectors in
Place. Preparatory to Charging After Battery Has Been
Opened and Shorts Removed
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The next operation is to put the battery on charge. Grasp
each post in the jaws of a pair of gas pliers and work the pliers
back and forth, Fig. 217, so as to remove the scale and allow the
connecting straps to make good contact. Now take a knife and cut
off the rough edges left in the connecting straps by the drill.
Taper the edge, if necessary to go on post. Turn the connectors
upside down and pound gently in position, Fig. 218, to make a good
connection. Temporary charging connections may also be made by
burning lead strips on the posts. This being properly done, the
battery is ready for charging. Check up the connections to be sure
they are correct.
Now put the battery on charge, and charge at a low rate. Do not
allow the temperature of any cell to rise above 110°F.
Continue the charge until the electrolyte clears up, and its
specific gravity stops rising and the plates have a normal color'
over their entire surface. Fully charged positive plates have a
chocolate brown color, and fully charged negative plates have a
dark gray color. By holding an electric light directly over a
cell, and looking down, the color of both negatives and positives
may be determined. Do not take the battery off charge until you
have obtained these results, although it may be necessary to
continue the charge for two, three, four, or five days. In this
preliminary charge it is not necessary to bring the gravity up to
1.280, because the electrolyte is not to be used again, and the
plates will become charged completely, regardless of what the
gravity is. The essential thing is to charge until the electrolyte
becomes perfectly clear, the gravity stops rising, and the plates
have the right color. The Cadmium test may be used here to
determine when the plates are charged. If the gravity rises above
1.280 during the preliminary charge, adjust it to 1.280 by drawing
out some of the electrolyte and adding distilled water. The
battery must stay on charge until you have the desired
conditions. If one cell does not charge,--that is, if its specific
gravity does not rise,--you have probably not freed all the
shorts, and must take the element out of the jar again and
carefully inspect it for more shorts.
Right here is where one of the most important questions may be
asked about rebuilding batteries. Why must you free the shorts and
put the battery on charge? Why not save time by putting in all new
separators, sealing the battery, burning on the cell connectors,
and then putting it on charge? If you have ever treated a battery
in this way, what results did you get? Why did you have a badly
unbalanced gravity of electrolyte? How could you know what
specific gravity electrolyte to put in each cell? Perhaps one was
charged, one only half charged, and the other dead. Suppose the
dead cell had impurities in it. How could you get rid of them?
Suppose the battery showed poor capacity on test, what would you
do?
Washing and
Pressing the Negatives
To continue the actual work on the battery. The battery
being fully charged,--the electrolyte clear, the plates of normal
color, the specific gravity no longer rising,--remove it from the
charging bench and put it on the work bench. Draw each element and
let drain as in Fig. 197.
Here again the labeled boxes described on page 183 come
in handy. Separate one group, remove the separators, and put one
group in each end of box to keep clean. Separate another group,
And nest the plates, Fig. 219, the negative with the negative, and
positive with positive. Separate the third element and put groups
in the boxes. Pour the old electrolyte out of the jars, and wash
out the jars as described on page 360. You now have the plates in
the best possible shape for handling. 'Fake the boxes containing
the plates to the sink. Have the plate press and the plate press
boards ready for use.
If, for any reason, you are called away from your work at this
point to be gone for five minutes, do not leave the fully charged
negatives exposed to the air, as they will become very hot. Cover
them with water. A one-gallon stone or earthenware jar will hold
the negative plates of a 100 ampere hour battery if you nest two
of the groups. You may also put negatives back in jars from which
they were taken, and fill with water.
Now hold a negative group under the faucet, and let a strong
stream of water run down over each plate so as to wash it
thoroughly, and to remove any foreign matter from the plate
surfaces. All negative groups must be handled in exactly the same
way so as to get the same results in each case.
After you have washed the first group, place it on edge on a
clean board with the post down and pointing away from you, and the
bottom of the group toward you. Now insert plate press boards
which are slightly larger than the plates, and of the exact
thickness required to fill the spaces between plates, Fig. 113.
For the standard 1/8 inch plates, a 5-16 inch board, or two 1/8
inch boards should be placed between plates.
The 1/8 inch boards are actually more than 1/8 inch thick, and
will give the proper spacing. For thin plates, use 1/4 inch
boards. Do not push the plate press boards more than 1/8 inch
above the tops of the plates, and be sure that the boards cover
the entire plates. Put a board on the outside of each end plate of
the group. In this way insert the plate press boards in each of
the three negative groups.
Then place each negative group on the lower jaw of the plate
press with the post of each group pointing toward you. Three
groups may be pressed at one time. Bring the top edges of the
transite boards flush with the front edge of the lower jaw of the
press, so that no pressure will be applied to the plate lugs. See
Fig. 114. Pressure applied to the plate lugs will break them
off.
Now screw down the upper jaw of the press as tightly as you can
with the handwheel, so as to put as much pressure on the plates as
possible. Leave the plates in the press for about five minutes.
Then remove them from the press, take out the boards, and replace
the plates in the battery jar from which they were removed, and
cover with water. They may also be placed in a stone or
earthernware jar and covered with water, especially if there is
any work to be done on the jars or case of the battery. If the
spongy lead of the negatives is firm, they may be reassembled in
the battery as soon as they have been pressed. If, however, the
spongy lead is soft and mushy, keep the negatives covered with
water for 12 to 24 hours. This will make them hard and firm. Then
remove them from the water and dry them in the air. In drying, the
plates will become heated and will steam. As soon as you notice
any steaming, dip the plates in water until they are cool. Then
remove them from the water and continue the drying process. Each
time the negatives begin to steam as they dry in the air, dip them
in the water until they are cool.
When the negatives are dry, they are ready to be reassembled in
the battery and prepared for service. Negatives treated in this
way will give good service for a much longer time than they would
if not treated in this way. The spongy lead has been made firm and
elastic. If you have other negatives in your shop which are not in
use, treat them in the same way and put them away for future use,
to use as rental batteries. Always put them through the same
process:
1. Charge them fully.
2. Press them in the plate press to force the spongy lead back
into the grids.
3. Soak them in water, if the spongy lead is soft and mushy,
for 12 to 24 hours, or even longer until the spongy lead is firm.
Dry them in the air, dipping them in water whenever they begin to
steam and become heated. This -will give you negatives that will
give excellent service and have a long life. Many negatives
treated in this way will be good for fifteen months to two years
of additional service. The rental batteries should be assembled in
the same way as those you are rebuilding for the owners.
The importance of pressing negatives cannot be exaggerated.
Always press the negatives of the batteries which you rebuild. Do
not do it to half, or three-fourths of the negatives, but to all
of them. The work takes but a few minutes, and the time could not
be put to better advantage. The spongy lead of the negatives
swells and bulges out and makes very poor contact with the grids
as a battery become,, discharged. This results in a loss of
capacity, gradual sulphation of the loose active material,
corrosion of the grids, failure of the gravity to rise high enough
on charge, overheating of the battery on charge, gassing before
the sulphate is reduced to active material with breaking off and
roughening of the active material, and makes the battery lazy and
sluggish in action. The spongy lead must make good contact with
the grids if the battery is to have a long life and give good
service.
No amount of charging will cure a negative with bulged, swollen
active material. Once this material becomes bulged nothing but
pressing will put it back where it belongs, and until it is
pressed back into the grids the plates are in a poor condition for
service. Even if the bulging is but very slight, the plates must
be pressed.
If you intend to use some of the positives, they should
now be washed. If you intend to use all new positives, throw away
the old ones, of course. The positives should not be held under
the faucet as the negatives were, because the stream of water will
wash out much of the positive active material. Rinse the positives
a number of times in a jar of clean water by moving them up and
down in the water. This will remove impurities from the surfaces
of the plates and wash off any foreign or loose materials. After
rinsing each positive group, replace it in the box.
Never attempt to straighten badly buckled positives, as the
bending cannot be done successfully, and the active material will
not have good contact with the grids. Positives cannot be pressed
as negatives can, because the positive active material lacks the
elasticity and toughness of the negative spongy lead. Slightly
buckled positives may sometimes be straightened by bending them
lightly all around the edges with a pair of thin, wide nosed
pliers. This should be (lone very carefully, however, and the
straightening done. gradually. If the plates cannot be
straightened in this way and the separators do not lie perfectly
flat against them without pinching at the corners, the plates
should be discarded, and new ones used in their place.
This is all the work to be done on the old plates, and those
which are to be used again are ready to be reassembled in the
battery. The process of treating the plates should be followed in
every battery that you rebuild, and the same steps should always
be taken, and in the same order. With one Standard method of
rebuilding batteries you will do 'uniformly good work and satisfy
all your customers. The essential thing for the success of your
battery business is to learn the Standard method and use it. Do
not rush a battery through your shop, and leave out some of the
steps of the process, even though the owner may be in a hurry. If
you have a good stock of rental batteries you can put one on his
car and keep it there until you have done as good a job of
rebuilding on his battery as you possibly can. Remember that the
Standard method which has been described has not simply been
figured out as being a good method. This method has been worked
out in the actual rebuilding of thousands and thousands of
batteries of all makes and in all conditions, and has produced
batteries full of life and power, ready to give one to two years
more of good, reliable service.
When you put new plates into a battery, or find some of
the plates broken from the connecting strap, it will be necessary
to burn the plates to the strap. Frequently you will find plates
which are otherwise in a good condition broken from the connecting
straps. This is most likely to happen when the plates have been
cast on to the connecting strap instead of being burned on. These
plates must be burned on.
New plates are frequently necessary. From pages 339 to 346 you
see that new plates are required under the following
conditions:
(a) Positives. Ruined by freezing; weak and brittle from age,
large part of active material shed; badly buckled; rotten and
disintegrated by impurities; reversed. Positives in a reasonably
good mechanical condition can be restored to a good electrical
condition by charging.
(b) Negatives. Active material granulated, bulged and
disintegrated; charged while dry; positives disintegrated by
impurities; ruined by overcharging; badly sulphated because
allowed to stand idle, or used while discharged; much active
material lost, and that which is left soft and mushy; negatives
reversed by charging battery backwards.
When making plate renewals, never install plates of different
design in the same group. Always use plates of the type intended
for the battery. The battery should first be fully charged, as
already explained. If all the plates in a group are to be
discarded, clamp the post in a vise, being careful not to crack
the hard rubber shell if one is on it, or to damage the threads on
Posts such as the Exide or to draw up the vise so tightly as to
crush the post. Then saw off all the old plates with a new coarse
toothed hacksaw, a sharp key hole saw, or any good saw which has a
wide set, close to the post. This separates the entire group of
plates from the post in one short operation. This method is much
better than the one of sawing the plates off below the connecting
strap, and sawing or punching the old plate ends out of the strap.
See page 217 for instructions for welding plates to the
straps.
The work on the jars consists of removing any sediment
which may have collected, washing out all dirt, and replacing
leaky jars. The removal of sediment and washing should be done
after the preliminary charge has been given and the old
electrolyte poured out unless the preliminary charge was given
with distilled water in the jars. The old electrolyte need not be
poured down the sewer, but may be kept in stone or earthenware
jars and used later in making electrical tests to locate leaky
jars.
Remove all sealing compound from the jar by means of a
hot putty knife, finishing by wiping with a gasoline soaked rag.
Inspect each jar carefully under a strong light for cracks and
leaks. If you know which jar is leaky by having filled each cell
with water up to the correct level, when you made the first
examination of the battery, and then having it allowed to stand
over night to see if the electrolyte in any cell has dropped below
the tops of the plates, no tests are necessary, but if you are in
doubt as to which jar, if any, is leaky, you must make tests to
determine which jar is leaky. If you know that there is no leaky
jar, because of the bottom of the case not being acid eaten and
rotted, it is, of course, not necessary to test the jars.
One test consists in filling the jar within about an inch of
the top with old or weak electrolyte, partly immersing the jar in
a tank which also contains electrolyte, and applying a voltage of
110 or 220 between the electrolyte in the jar and the electrolyte
in the tank in which the jar is partly immersed. If current Vows,
this indicates that the jar is leaky.
Fig. 220 shows the principle of the test. A suitable box,
-an old battery case will do, - is lined with sheet lead, and the
lead lining is connected to either side of the 110 or 220 volt
line. The box is then partly filled with weak electrolyte. The jar
to be tested is filled to within about one inch of the top with
weak electrolyte. The jar is immersed to within about an inch of
its top in the box. The top part of the jar must be perfectly dry
when the test is made, or else the current will go through any
electrolyte which may be wetting the walls of the jar. A lead
strip or rod, which is connected to the other side of the 110 or
220 volt line, through a lamp as shown, is inserted in the jar. If
there is, a leak in the jar, the lamp will burn, and the jar must
be discarded. If the lamp does not light, the jar does not leak.
Instead of using a lead lined box, a stone or earthenware jar
may be used. A sheet of lead should be placed in this jar, being
bent into a circular shape to fit the inside of the jar, and
connected to one side -of the line. The lead rod or sheet which is
inserted in the jar may be mounted on a handle for convenience in
making the test. The details of the testing outfit may, of course,
be varied according to what material is available for use. The
lamps should be suitably mounted on the wall above the tester.
This test may be made by using a voltmeter instead of
lamps, as shown in Fig. 221. If a voltmeter is used, be especially
careful to have the part projecting above the liquid perfectly
dry. A leaky cell will be indicated by a reading on the meter
equal to the line voltage.
A third method uses a Ford ignition coil, as shown in
Fig. 222. A leak will be indicated by a spark, or by the vibrator
making more noise than it ordinarily does. Instead of using the
Ford coil, as shown in Fig. 222, the test may be made as shown in
Fig. 223. Fill the jar to within an inch of the top with
electrolyte and immerse one of the high tension wires in the
electrolyte. Attach the other high tension wire to a wire brush,
comb, or rod having a wooden handle and rub it over the outside of
the jar. A leak is shown by a spark jumping to the jar.
The test may also be made without removing the jar. If
the lead lined box be made two feet long, the entire battery may
be set in the box so that the electrolyte in the box comes within
an inch of the top of the battery case. Fill each jar with weak
electrolyte and make the test as before. If this is done, however,
remove the battery immediately after making the test and wipe the
case dry with a cloth. To make the test in this way. the case must
be considerably acid eaten in order to have a circuit through it
to the jar.
The method of removing the jars from the case depends on
the battery. In some batteries the jars are set in sealing
compound. To remove a jar from such a battery, put the steam hose
from your steamer outfit into the jar, cover up the top of the jar
with rags, and steam the jar for about five minutes. Another way
is to fill the jar with boiling hot water and let it stand for
fully five minutes. Either of these methods will soften the
sealing compound around the jar so that the jar may be pulled out.
To remove the jar, grasp two sides of the jar with two pairs of
long, flat nosed pliers and pull straight up with an even, steady
pull. Have the new jar at hand and push it into the place of the
old one as soon as the latter is removed. The new jar should first
be steamed to soften it somewhat. Press down steadily on the new
jar until its top is flush with the tops of the other jars.
Some batteries do not use sealing compound around the jars, but
simply use thin wooden wedges to hold the jars in place, or have
bolts running through opposite faces of the case by means of which
the sides are pressed against the jars to hold them in place. The
jars of such batteries may be removed without heating, by removing
the wedges or loosening the bolts, as the case may be, and lifting
out the jars with pliers, as before. New jars should be steamed
for several minutes before being put in the case. When you put
jars into such batteries, do not apply too much pressure to them,
as they may be cracked by the pressure, or the jar may be squeezed
out of shape, and the assembling process made difficult.
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The case may be repaired with all the jars in
place, or it may be necessary to remove the jars. If the
case is to be junked and the jars used again, the case
may simply be broken off, especially if there is much
sealing compound around the jars.
Empty the old acid from the jars, take the case to the
sink and wash out all the sediment, Fig. 224. With the
pipe shown in Fig. '14, you have both hands free to hold
the case, as the water is controlled by' a foot operated
spring cock.
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If the case is rotten at top, patch it with good wood. If
the top and bottom are so rotten that considerable time will be
required to repair it, advise the owner to buy a new case.
Sometimes the top of the case can be greatly improved by
straightening the side edges with a small smoothing plane, and'
sometimes a 1/2 inch strip or more fitted all along the edge is
necessary for a good job. Handles that have been pulled, rotted,
or corroded off make disagreeable repair jobs, but a satisfactory
job can be done unless the end of the case has been pulled off' or
rotted. Sometimes the handle will hold in place until the battery
is worn out by old age if three or four extra holes are bored and
countersunk in the handle where the wood is solid, and common wood
screws, size 12, 1/2 or 5/8 inch long used to fasten the handle in
place. Sometimes it will be necessary to put in one half of a new
end, the handle being fastened to the new piece with brass bolts
and nuts before it is put into place. Sometimes you can do a good
job by using a plate of sheet iron 1-16 inch thick, and 4 inches
wide, and as long as the end of the case is wide. Rivet the handle
to this plate with stovepipe, or copper rivets, and then fasten
the plate to the case with No. 12 wood screws, 1/2 inch long.
If the old case is good enough to use again, soak it for
several hours in a solution of baking soda in water to neutralize
any acid which may have been spilled on it, or which may be
spilled on it later. After soaking the case, rinse it in water,
and allow it to dry thoroughly. Then paint the case carefully with
asphaltum paint.
Reassembling the Elements
Take a negative group and put it on edge on a board, with
post away from you, and lower edge toward you. Mesh a positive in
the negative group. The groups are now ready for the separators.
Take six moist separators from your stock. Slip one into position
from the bottom in the middle of the group, with the grooved side
toward the positive plate, spreading the plates slightly if
necessary. Take another separator, slip it into position on the
opposite side of the positive against which your first separator
was placed. In this way, put in the six separators, with the
grooved side toward the positives, working outward in both
directions from the center, Fig. 225. The grooves must, of course,
extend from the top to the bottom of the plate. Now grasp the
element in both hands, and set it right side up on the block,
giving it a slight jar to bring the bottoms of the plates and
separators on a level.
Now grasp the element in both hands, and set it right
side up on the block, giving it a slight jar to bring the bottoms
of the plates and separators on a level.
Next take a cover, and try it on the posts, Fig. 226. Pull the
groups apart slightly, if necessary, before inserting any more
separators, so that the cover fits exactly over the posts, Fig.
227. See that the separators extend the same distance beyond each
side of the plates. You may take a stick, about 10 inches long, 1
1/2 inches wide, and 7/8 inch thick, and tap the separators gently
to even them up. A small wood plane may be used to even up the
side edges of wood separators. If you put in too many separators
before trying on the cover, the plates may become so tight that
you may not be able to shift them to make the cover fit the posts
or you may not be able to shift the separators to their proper
positions. It is therefore best to Put in only enough separators
to hold the groups together and so they can be handled and yet
remain in their proper position when set up on the block. Without
separators, the posts will not remain in position.
With the element reassembled, and the remaining separators in
their proper positions, see that all the plates are level on
bottom, and no foreign matter sticking to them. Place the element
in box shown in Fig. 219 to keep clean. Reassemble the other
elements in exactly the same way, and put them in the box. The
elements are now ready to be put in the jars.
Steam the jars in the steamer for about five minutes to
soften them somewhat, so that there will be no danger of breaking
a jar when you put in the elements.
With the case ready, look for the "+", "P" or "POS" mark on it.
(Cases which are not marked in this way at the factory should be
marked by the repairman before the battery is opened.) Place the
case so that this mark is toward you. Grip an element near the
bottom in order to prevent the plates from spreading, and put it
in the jar nearest the mark, with the positive post toward you,
next to the mark. Put an element in the next jar so that the
negative post is toward you. Put an element in the third jar so
that the positive post is toward you, and so on. The elements are
correctly placed when each connecting strap connects a positive to
a negative post. If the case has no mark on it, reassemble exactly
according to the diagram you made on the tag before you opened the
battery. Set the jars so that the posts are exactly in line so
that the cell connectors will
fit.
If an element fits loosely in the jar, it must be
tightened. The best way to do this is to put one or more
separators on one or both sides of the elements before putting it
in the jar, Fig. 228. If you leave the elements loose in the jars,
the jolting of the car will soon crack the sealing compound, and
you will have a "slopper" on- your hands.
If element fits very tight, be sure that the corners of the
plate straps have been rounded off and trimmed flush with outside
negatives. Be sure also that there is no compound sticking to the
inside of jars. Take care not to break the jar by forcing in a
tight fitting element when the jar is cold and stiff.
Filling Jars with
Electrolyte or Putting on the Covers
With all the elements in place in the jars, one of two
things may be. done. First, the jars may be filled with
electrolyte and the covers then sealed on, or the covers may first
be sealed on and the jars then filled with electrolyte. Each
method has its advantages and disadvantages. If the jars are first
filled with electrolyte, acid may be splashed on the tipper parts
of the jars and sealing made very difficult.
On the other hand, if the electrolyte is first poured in, the
charged negatives will not become hot, and sealing compound which
runs into the jar will be chilled as soon as it strikes the
electrolyte and will float on top and do no harm. If the covers
are sealed before any electrolyte is added, it will be easier to
do a good sealing job, but the negatives will heat up.
Furthermore, any sealing compound which runs into the jar will run
down between the plates and reduce the plate area.
If care is taken to thoroughly dry the upper parts of the jars,
add the electrolyte before sealing on the covers.
If you have followed the directions carefully, and have
therefore freed all the shorts, have thoroughly charged the
plates, have washed and pressed the negative groups, have washed
the positives, have then added any new plates which were needed,
and have put in new separators, use 1.400 specific gravity
electrolyte. This is necessary because washing the plates removed
some of the acid, and the new separators will absorb enough acid
so that the specific gravity after charging will be about 1.280.
The final specific gravity must be between 1.280 and 1.300. In
measuring the specific gravity the temperature must be about
70°F., or else corrections must be made. For every three
degrees above 70°, add one point (.001) to the reading you
obtain on the hydrometer. For every three degrees under 70°,
subtract one point (.001) from the reading you obtain on the
hydrometer. For instance, if you read a specific gravity of 1.275
and find that the temperature of the electrolyte is 82°F.,
add ((82-70)/3 = 4)
four points (1.275 + .004), which gives 1.279, which is
what the specific gravity of the electrolyte would be if its
temperature were lowered to 70°. The reason this is done is
that when Ave speak of an electrolyte of a certain specific
gravity, say 1.280, we mean that this is its specific gravity when
its temperature is 70°F. We must therefore make the
temperature correction if the temperature of the electrolyte is
much higher or lower than 70°F.
This operation is a particular one, and must be done
properly, or you will come to grief. Get the box containing the
covers and connectors for the battery you are working on; take the
covers, and clean them thoroughly. There are several ways to clean
them. If you have gasoline at hand, dip a brush in it and scrub
off the compound. The covers may also be cleaned off with boiling
water, but even after you have used the hot water, it will be
necessary to wipe off the covers with gasoline. Another way to
soften any compound which may be sticking to them, is to put the
covers in the Battery Steamer and steam them for about ten
minutes. This will also heat 'the covers and make them limp so
that they may be handled without breaking.
If the covers fit snugly all around the inside- of the jars so
that there is no crack which will allow the compound to run down
on the elements, all is well and good. If, however, there are
cracks large enough to put a small, thin putty knife in, you must
close them. If the cracks are due to the tops of the jars being
bent out of shape, heat the tops with a soft flame until they are
limp, (be careful riot to burn them). Now, with short, thin wedges
of wood, (new dry separators generally answer the purpose), crowd
down on the outside edges of the jar, until you have the upper
edge of jars straight and even all around. If the jars are set in
compound, take a hot screwdriver and remove the compound from
between the jar. and case near the top. If the cracks between
cover and jar still remain, calk them with asbestos packing, tow,
or ordinary wrapping string. Do not use too much packing;--just
enough to close the cracks is sufficient. When this is done, see
that the top of the case is perfectly level, so that when the
compound is poured in, it will settle level all around the upper
edge of the case.
Sealing Compounds
There are many grades of compounds (see page 149), and
the kind to use must be determined by the type of battery to be
sealed. There is no question but that a poor grade used as
carefully as possible will soon crack and produce a slopper. A
battery carelessly sealed with the best compound is no better.
The three imperative conditions for a permanent lasting job
are:
1. Use the best quality of the proper kind of compound for
sealing the battery on hand.
2. All surfaces that the compound comes in contact with must be
free from acid and absolutely clean and dry.
3. The sealing must be done conscientiously and all details
properly attended to step by step, and all work done in a
workmanlike manner.
With respect to sealing, batteries may
be divided into two general classes. First, the old type battery
with a considerable amount of sealing compound. This type of
battery generally has a lower and an upper cover, the vent tube
being attached or removable, depending on the design. The compound
is poured on top of the lower cover and around the vent tube, and
the top covers are then put on. Most of the batteries of this type
have a thin hard rubber sleeve shrunk on the post where the
compound comes in contact with it; this hard rubber sleeve usually
has several shallow grooves around it which increase its holding
power. This is good construction, provided everything else is
normal and the work properly done with a good stick-, compound.
There are a few single cover batteries with connecting straps
close to top of covers, and the compound is poured over the top of
the straps. See Fig. 262.
The second general type consists of single one-piece cover
batteries that have small channels or spaces around the covers
next to the jars into which the sealing compound is poured. This
type of battery is the most common type.
Compound in bulk or in thin iron barrels can be cut into small
pieces with a hatchet or hand ax. To cut off a piece in hot
weather, strike it a quick hard blow in the same place once or
twice, and a piece will crack off. Directions for properly beating
sealing compound will be found on page 150.
Sealing Double
Cover Batteries
The following instructions apply to batteries having
double covers. These are more difficult to seal than the single
cover batteries. If you can seal the double cover batteries well,
the single cover batteries will give you no trouble.
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Always start the fire under the compound before
you are ready to use it, and turn the fire lower after it
has melted, so as not to have it too hot at the time of
pouring. If you have a special long nosed pouring ladle,
fill it with compound by dipping in the pot, or by
pouring compound from a closed vessel. If you heat the
compound in an iron kettle, pour it directly into pouring
ladle, using just about enough for the first pouring. The
compound should not be too hot, as a poor sealing job
battery will result from its use. See page 150.
Before sealing, always wipe the surfaces to be sealed
with a rag wet with ammonia or soda solution, rinsed with
water, and wiped dry with a rag or waste. If you fail to
do this the compound will not stick well, and a top leak
may develop. Then run a soft lead burning flame over the
surfaces to be sealed, in order to have perfectly dry
surfaces. Remember that sealing compound will not stick
to a wet surface.
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Pour compound on the lower covers, as in Fig.
229. Use enough to fill the case just over the tops of
the jars, Fig. 230. Then pour the rest of the compound
back in compound vessel or kettle. To complete the job,
and make as good a job as possible, take a small hot lead
burning flame and run it around the edges of case, tops
of jars, and around the posts until the compound runs and
makes a good contact all around. If you have an electric
fan, let it blow on the compound a few minutes to cool
it, as in Fig. 231. Then the compound used for the second
pouring may be hotter and thinner than the first.
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Fill the pouring ladle with compound, which is thinner
than that used in the first pouring, and pour within 1/16 inch of
the top of the case, being careful to get in just enough, so
that-after it has cooled, the covers will press down exactly even
with the top of the case, Fig. 232. It will require some
experience to do this, but you will soon learn just how much to
use.
As soon as you have finished pouring, run the flame all around
the edges of the case and around the post, being very careful not
to injure any of the vent tubes. A small, hot-pointed flame should
be used. Now turn on the fan again to cool the compound.
While the compound is cooling, get the cell connectors and
terminal connectors, put them in a two-quart granite stew pan,
just barely cover with water, and sprinkle a tablespoon of baking
soda over them. Set the stew pan over the fire and bring water to
boiling point. Then pour the water on some spot on a bench or
floor where the acid has been spilled. This helps to neutralize
the acid and keep it from injuring the wood or cement. Rinse off
the connectors and wipe them dry with a cloth, or heat them to dry
them.
Now take the top covers, which must be absolutely clean and
dry, and spread a thin coat of vaseline over the top only, wiping
off any vaseline from the beveled edges. Place these covers right
side up on a clean board and heat perfectly limp with a large,
spreading blow torch flame. Never apply this flame to the under
side of the top covers. The purpose is to get the covers on top of
the battery absolutely level, and exactly even with the top of the
case all around it, and to have them sticking firmly to the
compound. There is not an operation in repairing and rebuilding
batteries that requires greater care than this one, that will show
as clearly just what kind of a workman you are, or will count as
much in appearance for a finished job. If you are careless with
any of the detail, if just one bump appears on top, if one top is
warped, if one cover sticks above top of case, try as you may, you
never can cover it up, and show you are a first-class workman. See
that you have these four conditions, and you should not have any
difficulty after a little experience:
1. You must have just enough compound on top to allow the top
covers to be pressed down exactly even with upper edge of
case.
2. The top covers must be absolutely clean and have a thin coat
of vaseline over their top, but none on the bevel edge.
3. A good sized spreading flame to heat quickly and evenly the
tops to a perfectly limp condition without burning or scorching
them.
4. Procure a piece of 7/8-inch board 1-1/2 inches wide and just
long enough to go between handles of battery you are working on.
Spread a thin film of oil or vaseline all over it.
Having heated the covers and also the top surface of the
compound until it is sticky so that the covers may be put down far
enough and adhere firmly to it, place the covers in position. Then
press the covers down firmly with a piece of oiled wood, as in
Fig. 233, applying the wood sidewise and lengthwise of case until
the top of cover is exactly even with the top of the case. It may
be necessary to use the wood on end around the vent tubes and
posts as in Fig. 234, to get that part of the cover level. If the
compound comes up between covers and around the edges of the case,
and interferes with the use of the wood, clean it out with a
screwdriver. You can then finish without smearing any compound on
the covers.
When you have removed the excess compound from the cracks
around the edges of the covers with the screwdriver, take a large
iron spoon which has the end bent into a pouring lip, and dip up
from 1/2 to 2/3 of a spoonful of melted compound (not too hot).
Wipe off the bottom of the spoon, Fig. 235, and pour a small
stream of compound evenly in all the cracks around the edges of
the covers until they are full, as in Fig. 236. Do not hold the
spoon too high, and do not smear or drop any compound on top of
battery or on the posts. No harm is done if a little runs over the
outside of the case, except that it requires a little time to
clean it off. A small teapot may be used instead of the spoon. If
you have the compound at the right temperature, and do not put in
too much at a time, you will obtain good results, but you should
take care not to spill the compound over covers or case.
After the last compound has cooled, --this
requires only a few minutes, --take a putty knife, and
scrape off all the surplus compound, making it even with
the top of the covers and case, Fig. .237. Be careful not
to dig into a soft place in the compound with the putty
knife. If you have done your work right, and have
followed directions explicitly, you have scraped off the
compound with one sweep of the putty knife over each
crack, leaving the compound smooth and level. You will be
surprised to see how finished the battery looks.
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Some workmen pour hot compound clear to the top of the
case and then hurry to put on a cold, dirty top. What happens? The
underside of the cover, coming in contact with the hot compound,
expands and lengthens out, curling the top surface beyond
redemption. As you push down one corner, another goes up, and it
is impossible to make the covers level.
Sealing Single
Cover Batteries
Single cover batteries are scaled in a similar manner.
The covers are put in place before any compound is poured in.
Covers should first be steamed to make them soft and pliable. The
surfaces which come in contact with the sealing compound must be
perfectly dry and free from acid. Before pouring in any compound,
run a soft flame over the surfaces which are to be sealed , so as
to dry them and warm them. Close up all cracks between Jars and
covers as already directed. Then pour the cover channels half full
of sealing compound, which must not be too thin. Now run a soft
flame over the compound until it flows freely and' unites with the
covers and jars. Allow the compound to cool.
For the second pouring, somewhat hotter compound may be used.
Fill the cover channels flush with the top of the case, and again
run a soft flame over the compound to make it flow freely and
unite with the covers, and to give it a glossy finish. If any
compound has run over on the covers or case, remove it with a hot
putty knife.
Burning-on the Cell
Connectors
With the covers in place, the next operation is to burn
in the cell connectors. Directions for doing this are given on
page 213. If you did not fill the jars with electrolyte before
sealing the covers, do so. now. See page 364.
You should have a set of stencil letters and mark every
battery you rebuild or repair. Stamp "POS," "P," or "+" on
positive terminal and "NEG," "N," or on negative terminal. Then
stamp your initials, the date that you finished rebuilding the
battery, and the date that battery left the factory, on the top of
the connectors. Record the factory date, and type of battery in a
book, also your date mark and what was done to the battery. By
doing this, you will always be able to settle disputes that may
arise, as you will know when you repaired the battery, and what
was done.
To go one step farther, keep a record of condition of plates,
and number of new plates, if you have used any. Grade the plates
in three divisions, good, medium and doubtful. The "doubtful"
division will grow smaller as you become experienced and learn by
their appearance the ones to be discarded and not used in a
rebuilt battery. There is no question that even the most
experienced man will occasionally make a mistake in judgment, as
there is no way of knowing what a battery has been subjected to
during its life before it is brought to you.
Cleaning and Painting
the Case
The next operation is to thoroughly clean the case;
scrape off all compound that has been spilled on it, and also any
grease or dirt. If any grease is on the case, wipe off with rag
soaked in gasoline. Unless the case is clean, the paint will not
dry. Brush the sides and end with a wire brush; also brighten the
name plate. Then coat the case with good asphaltum paint. Any good
turpentine asphaltum is excellent for this purpose. If it is too
thick, thin it with turpentine, but be sure to mix well before
using, as it does not mix readily. Use a rather narrow brush, but
of good quality. Paint all around the upper edge, first drawing
the brush straight along the edges, just to the outer edges of
rubber tops. Now paint the sides, ends and handles, but be careful
not to cover the nameplate. To finish, put a second, and
thick coat all around top edge to protect edge of case.
Paint will soak in around the edge on top of an old case more
easily than on the body of the case as it is more porous.
Charging the
Rebuilt Battery
With the battery completely assembled, the next step is
to charge it at about one-third of the starting or normal charge
rate. For batteries having a capacity of 80 ampere hours or more,
use a current of 5 amperes. Do not start the charge until at least
12 hours after filling with electrolyte. This allows the
electrolyte to cool. Then add water to bring electrolyte up to
correct level if necessary. The specific gravity will probably at
first drop to 1.220-1.240, and will then begin to rise.
Continue the charge until the specific gravity and voltage do
not rise during the last 5 hours of the charge. The cell voltage
at the end of the charge should be 2.5 to 2.7, measured while the
battery is still on charge. Make Cadmium tests on both positive
and negatives. The positives should give a Cadmium reading of 2.4
or more. The negatives should give a reversed reading of 0.175.
The tests should be made near the end of the charge, with the cell
voltages at about 2.7. The Cadmium readings will tell the
condition of the plates better than specific gravity readings. The
Cadmium readings are especially valuable when new plates have been
installed, to determine whether the new plates are, fully charged.
When Cadmium readings indicate that the plates are fully charged,
and specific gravity readings have not changed for five hours, the
battery is fully charged. If you have put in new plates, charge
for at least 96 hours.
Measure the temperature of the electrolyte occasionally, and if
it should go above 110°F., either cut down the charging
current, or take the battery off charge long enough to allow the
electrolyte to cool below 90°F.
Adjusting
the Electrolyte
If the specific gravity of the electrolyte is 1.280 to
1.300 at the end of the charge, the battery is ready for testing.
If the specific gravity is below or above these figures, draw off
as much electrolyte as you can with the hydrometer. If the
specific gravity is below 1.280, add enough 1.400 specific gravity
electrolyte with the hydrometer to bring the level up to the
correct height (about 1/2 inch above tops of plates). If the
specific gravity is above 1.300, add a-similar amount of distilled
water instead of electrolyte. If the specific gravity is not more
than 15 points (.015) too low or too high, adjust as directed
above. If the variation is greater than this, pour out all the
electrolyte and add fresh 1.280 specific gravity electrolyte.
After adjusting the electrolyte, continue the charge until the
gravity of all cells is 1.280-1.300, and there is no further
change in gravity for at least two hours. Then take the battery
off charge and make a final measurement of the specific gravity.
Measure the temperature at the same time, and if it varies more
than 10° above or below 70°, correct the hydrometer
readings by adding one point (.001 sp. gr.) for each 3 degrees
above 70°, and subtracting one point (.001 sp. gr.) for each
3 degrees below 70°. Be sure to wipe off any electrolyte
which you spilled on the battery in adjusting the electrolyte or
measuring the specific gravity. Use a rag dipped in ammonia, or
baking soda solution.
Whenever you have time to do so, make a 20-minute high
rate discharge test on the rebuilt battery, as described on page
266. This test will show up any defect in the battery, such as a
poorly burned joint, or a missing separator, and will show if
battery is low in capacity. If the test gives satisfactory
results, the battery is in good condition, and ready to be put
into service, after being charged again to replace the energy used
by the test.
Source: http://www.powerstream.com/1922/battery_1922_WITTE/batteryfiles/chapter15.htm
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