Chapter 15 — Rebuilding the Battery
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:
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.