Another name for your car battery.

First, I will quote verbatim from The New World Encyclopaedia Circa 1935.

This is the simplest most concise technical description I could find of a battery. I will skip the bit about the ‘funny” old types that no one ever uses and get right into the Lead Acid one.

BATTERY (Electric). The most important electric battery is the accumulator. Theoretically the reactions taking place in any battery are reversed when a current is sent through it in the opposite direction to that which it delivers current There are only two at most three satisfactory types of accumulator. the oldest of these is the lead accumulator, which consists essentially of plates of spongy lead dipped into sulphuric acid. When a current is passed through this, hydrogen is evolved at the negative pole, while the lead on the positive pole is oxidised to peroxide. If the current is now stopped the cell will deliver a current, in the course of which the lead plate becomes changed into lead sulphate, part of which goes into solution, while the positive plate is reduced to lead in exactly the same way as the copper oxide is reduced to copper in the Edison-Lalande cell. In actual practice it is usual to construct the plates by starting with lead peroxide for the one and litharge or sponge lead for the other.

The most serious drawback to the lead accumulator is its sensitivity to bad treatment.

If it is allowed to stand discharged quite a short time, the positive plate is attacked by the acid and converted into sulphate, which becomes crystallised, as does the sulphate on the negative plate. The capacity of the accumulator, however obviously depends on the plates having their active material in a very fine state of division, and hence a sulphated accumulator, though the chemical changes can be reversed by recharging several times, never regains anything like its former capacity.

The other accident to which any accumulator is subject is short circuit. This produces disastrous results in lead accumulators, causing the plates to buckle and the filling to be loosened.

Acts & Facts

Batteries......of the Lead Acid Type.

Now a few snippets that have enabled me to live with them in some degree of harmony.

First rule: Remember the wet stuff in them is strong sulphuric acid (electrolyte) which varies from strong to very strong depending on the state of charge of the battery.

It also has some undesirable side effects, such as corroding most metals it touches, eating holes in anything organic, and doing quick and nasty damage to personal body parts.

Keep this in mind whenever you handle a battery. If possible wear rubber gloves. Always wear old clothes, and when carrying one put a whole newspaper between you and it. Better still use a proper carrying strap.

As well as containing acid they also have in them lots of ergs (energy), and like the electrolyte must be treated with utmost respect. To give some idea how much respect, consider: When you press the starter button on a 1952 Holden with its 6 volt system, the first moment till the motor starts to turn over the battery output is around 600amps which then drops back to 200amps turning the motor. Compare this with 75 to 140 amps you use to arc weld. Hence the 1/2 inch diameter cables to carry the load.

“What has this got to do with anything?” You may ask.

I venture to say, most mechanics have a screwdriver or spanner with scars from inadvertently shorting a battery!

When you work on the starter side of things; there is no fuse to protect you.

It is advisable to avoid rings on fingers when groping under the bonnet. (They are OK in ears, nose, and navel).

Metal watchbands are a definite No-No...I have a friend who shorted his while wrestling with his Morris Minor. Suddenly he had a stunning roasted replica of an expanded band round his left wrist. It even annealed the springs in the band.

Let’s face it. Batteries aint what they used to be!

My father was, in the 1920s a battery mechanic with Willard Batteries, and later, after WW2 a lead burner with A.G.Healings making batteries.

In those days when batteries were made with ‘Vulcanite’ cases, they had a ‘sump’, which was a space underneath the plates into which the lead paste settled as it fretted out of the grids of the plates. There it accumulated out of harm’s way until it reached the plates, shorted them and the battery died. This process took 5 to 10 years in a well cared for car battery. and nearly twice that for stationary ones in lighting plants. These days you pay extra for a battery that may last 3 years.

Why is this so? In order to sell more batteries, and to make way for all the other technicalogical junk under the bonnet!

The straps and sometimes even the posts were removed, and most importantly the sump was dispensed with. This makes the battery smaller with about the same capacity. As soon as there is any accumulation of sediment in the bottom the battery ‘karks it’. Moral: The deeper the case, the longer you can expect the battery to last.

There are still places that rebuild batteries, so if you have an old deep case. That’s the way to go.

There are two main enemies of lead acid batteries.

First is being left discharged.

This causes the lead paste to turn to lead sulphate which is electrically bad news and dramatically shortens its life. Moral: Keep it well charged.

If in doubt put it on a trickle charge (about 1amp) for a day or two.

Some people have a ‘thing’ about always taking the filler plugs out of a battery whenever it is put on charge. I am quite prepared and willing to be corrected on this piont. But! If a generator can pump 10 or more Amps, and an alternator 40 odd Amps, into a battery under the bonnet. Why doesn’t it explode there?? I certainly don’t have any problems with my 2.5 sometimes Amps charger.

Second is contamination of the electrolyte.

Be very careful what you put in it. When you peer into the holes on the top there should always be enough acid to cover the plates by about 3/8 of an inch. There is usually some sort of indicator built into the filler plug hole. If you over fill a cell (there’s one for each filler hole), when the battery is fully charged it may overflow. (Reread what happens when acid gets on things). Plus the electrolyte becomes diluted.

Electrolyte is lost three ways.

Being spilt: How, when, and why!?

Evaporation: Which takes a very long time, or too hot location.

Gassing: Caused by a high rate of charging, and or, normal use.

Disregarding the first two. Gassing is evident if you look in the filler hole when the battery is on a charger, or the engine is running, or even immediately after charging has stopped. There will be bubbles rising from the plates.

A word of caution here. Those bubbles are produced by electric current breaking down the water in the electrolyte to hydrogen and oxygen. In water (H2O) these two are OK, but when separated as gasses and mixed they are explosive.

(A digression here!) At Willard Batteries they used to cycle (charge and discharge) the batteries about 50 at a time. The current came from live bus bars along the bench. The rule was to switch off the current when connecting or disconnecting a battery. Needless to say there was plenty of hydrogen being generated. Every so often someone (my Dad included) flouted the rule and the spark created would explode one or a string of batteries. Dad did it once too often. Having his head held under a cold tap for 20 minutes was hard to forget! Only his glasses saved his sight.

The charging rate on an Austin-7 (8amps) is regulated by the third brush in the generator and does more to protect the generator than the battery. In your ‘modern’ the voltage regulator is adjustable and looks after things.

If gassing is too vigorous the bubbles will dislodge the lead paste and shorten the battery life. If there it any sign of the battery warming itself, this indicates overcharging.

Back to what to put in the battery to maintain the electrolyte level. This shouldn’t need doing more than once or twice a year.

Never! and I stress Never! put tap water in a battery!!!

It is full of metallic salts, iron, zinc, aluminium, and others. Some of which might be good for you but poison to a battery. Unfortunately even rain water is suspect these days.

From time to time products appear on the market claimed to increase battery performance/life. My late friend who was a chemist with CSIRO spent 2 years on battery research and tested these products. The result was always the same, none worked.

When the electrolyte needs topping up the only thing to use is distilled water. As pure as you can get, anything else will upset the chemistry of the battery and destroy it.

You can buy distilled water at the garage for about $3 per litre, or make it yourself. as follows.

Take a shallow glass dish and put an inch of tap or rain water in it. Place in the frig or freezer.

When 1/4 to 3/8 inch of ice has formed on top, remove the dish and poke a hole through the ice at one edge and carefully drain away the water and any sediment underneath. Melt the ice. This is ‘freeze distillation’, or ‘zone refining’. If you are keen you can repeat the process using the melted ice water to make it double distilled.

Explanation: As water freezes pure water turns to ice first and floats to the top concentrating the impurities in the unfrozen water beneath. The main thing is to avoid contact of the purified water with any metal.

A Hydrometer is an excellent investment($5 to $6).This is the only device to tell exactly the state of charge of a battery. It look like a turkey basting syringe with a coloured glass float inside. What you do is gently and carefully suck the electrolyte up into it until the float inside floats. The level of the acid on the float calibration indicates the density (Specific Gravity) of the acid which is directly related to the amount of charge in the battery. If the reading is low put the battery on charge. If it is very high check the level of the acid in the battery and view the charging rate with deep suspicion.

The electrolyte should be water clear in the hydrometer. If it is cloudy you have problems. Even if it is still functioning the battery may not be trustworthy... Another indicator a battery is unwell is variation of SG from one cell to another. Don’t transfer any acid from one cell to another.

When you finish using the hydrometer wash and flush it thoroughly or it will eat holes in everything it touches.

If and when enough electrolyte or its vapour seeps out of your battery and white chalky growth appears on nearby steel parts (green if they are brass), gently pour very hot tap water on them and it should disappear like magic, even quicker if you lace the water with bicarb soda. BUT! be careful not to allow any of it to get into the vent holes in the filler plugs.

If like me, you remember the rubber gloves afterwards instead of before, be sure to wash your hands very thoroughly with plenty of toilet soap. You will know straight away that, not if, you have acid in them, because the soap won’t lather properly. If you have the slightest trace of acid, if it doesn’t make a hole, certainly will bleach any clothing you touch. (Been there, done that!).

Peter Booth

Sharpen a Blunt File?

Blunt File

Who said you could sharpen a blunt file? Answer: My Dad! On a number of occasions he mentioned sharpening files using sulphuric acid, but I never saw him to do so. In keeping with my credo of not advocating doing anything I haven't done myself, I decided to give it a try. The trusty battery I bought at the 70th Anniversary Hub Rally at Canberra died with dignity late last year requiring me to unearth the one it replaced and have it rebuilt. This provided me the opportunity and the acid to try to sharpen a file or three. With due respect for the nasty nature of the electrolyte I drained the acid out of the recently deceased battery into a tall slim Fowlers preserving jar which I then stood in a plastic dish in case the process heated up and broked it.

I take no pride in the fact that I am the possessor of the greatest variety of blunt files in this country, from a 4" smooth to a 14" coarse bastard, (by the way that is it's proper name). I lowered a file into the acid and waited for something to happen, and it did. It grew lots of tiny bubbles on it's surface and gently gassed. About 24 hours later I removed it, washed it under running water using a flat barbecue brush and a pair of tongs, then soaked it in a plastic dish of clean water for another day, washed it again, dried it, and tried it. I did 5 files of various cuts and sizes leaving each one 4 to 6 hours longer than the last as the acid grew progressively greener and a greenish residue collected in the bottom of the jar. Finally I started to worry about the possibility of the vapour rusting things nearby in my workshop and disposed of the exhausted electrolyte.

I have used several of the 'sharpened' files since and they are just great!

A word of warning! If you do try this remember you are handling a very nasty, corrosive poison.