Recharging car battery

[J Burns]

A neighbor had trouble with his 2-year battery after 2 years, so he replaced it. I got 11 more years out of it.

I normally didn't take that car more than 5 miles, so the battery didn't endure much heat and vibration. Several times a year, I'd put it on an automatic pulse charger. I'd plug the charger into a $15 watt meter. Even if a battery starts out 90% charged, it can take hours to get all the sulfate out of the plates and into the electrolyte. I'd leave it on until the wattage no longer dropped significantly in half an hour.

When you hit the starter, sulfates can flake off. You lose plate material, and when they accumulate on the bottom, electrical leakage can speed up self-discharge. Left on, sulfates eventually harden, making more and more of the plate useless.

Sulfation from self-discharge shortens the life of mower batteries left over the winter. It would make sense to charge them periodically, especially before cranking in the spring. I went to AGM for lower self-discharge and better vibration resistance. Then I read that charging above 120 F will shorten the life of AGM. An IR thermometer showed the battery was getting nearly that warm even in cool weather. I shoved a piece of foil-covered insulating board between the battery and the engine. It made a big difference.

The OEM battery was 320 CCA. The AGM I found was 160. Then I read that the OEM battery is 160 in another brand of mower with the same engine, so I bought the AGM. Sometimes, it won't turn the engine over. If I let off the key and immediately turn it again, it will crank merrily. I guess if I catch the engine around bottom dead center, the battery won't provide enough torque to overcome compression. I wonder if that means a

160 CCA AGM won't provide the same starting surge as a 160 CCA conventional battery.

[clare]

If I remeber correctly they were just a big rheostat and the rectifier tube, so they could put out almost half the peak to peak voltage of the supply. Nominal 120 volt RMS is about 170PP - - Half of that is 85 volts. which can charge 32 cells at 2,6 volts each.

Our local battery supplier has a 220 volt Tungar charger that would maintain a string of 10 12 volt batteries, and I think I remember some used "powerstats" instead of rheostats and could put out double the AC line voltage into the tube.

I know that the garage where I did my apprenticeship had one of the earliest metal plate rectifier high current battery chargers. The rectifier was about a foot square and I think it dated to pre-WW2.. Also had the little Tungar bulk charger. Out tow truck was a 1943? ex military PowerWagon

[clare]

The 6 volt Vdub and the 12 volt VDub had different sized flywheels too. (which is why , generally, when converting a 6v to 12v the starter was not changed) Dodge Brothers used 12 volts back around 1915. BAck in the forties,Buick used Neg ground, Cadillac Pos , Chevy Neg, Chrysler Pos,, Olds Neg, Studebaker Pos, and Pontiac Neg. Willys used Negative as well, but most of the rest used Pos. - and virtually all cars of THAT era were 6 volt. When the switchover to 12 volts occurred, most North American manufacturers standardized on Neg fround - It took the British manufacturers till the late sixties to complete the switchover to Neg ground at least for the North American Market)

[clare]

There is a lot to be said for "experienced parts" over "new parts". You KNOW the "experienced" part has a history of working, while the "new" part is an unknown entity. If I have any question about my batteries I have a midtronics tester put on early in the fall to see what condition they are in. If they are questionable or weak, I replace them Otherwize they try for another year. The original battery in my 1980 Corolla went 8 years. The battery in my 1988 Chrysler went

12, IIRC. The brand new Canadian Tire Lifetime Warranty battery in the Ambassador lasted 6 months for the first one, 9 months for the second one, and was still in the car when I sold it about a year later. The length of the warranty has nothing to do with the quality of the battery. I generally get 6 or more years out of Interstate Megatron batteries in my vehicles. The first CTC battery in the Ambassador failed, appropriately enough, half way accross the Ambassador Bridge while returning from Detroit to Windsor. We coasted all the way down to the customs booth, got a boost, and made it to the closest Canadian Tire store.(where I had to buy a new battery because the reciept was at home in Waterloo) When I took the dead battery and both reciepts to the Waterloo store I got the refund for the dead battery.

[philoÂÂ]

I have several of them and none have rheostats, all use transformer taps and heavy duty rotary switches.

The Tungar bulb filament takes a lot of current. As much as half of the total power consumed goes to light it.

The oldest one I have is from 1932 or so, still works fine!

Also have a few from the 50's

[Higgs Boson]

[...].

What is a "blemished" new brand name battery? Cosmetic? Or?

TIA

HB

[Stormin Mormon]

The Interstate store near me sells "blems" which have different or no stickers. Cosmetic problem of some kind. I've found them to be good quality.

When my Dad died, I took his old dead battery to Interstate. The guy tested a couple things, and then gave me a new battery with not so much as form to sign. Smile, no charge, off you go. I was astounded, thrilled, and such. The battery worked fine, the car sold.

[philoÂÂ]

Here is that photo of the 6 amp Tungar rectifier tube

next to it ans an 85 amp silicon diode

[clare]

[clare]

That would give you a 10 volt battery when it shorted. More plausible explanation would be what I had on more than one battery - the last one on the Aerostar - where the intercell link would open under certain conditions. Absolutely stone dead - come back an hour later after the sun had warmed up the car a bit, and it would start perfectly. That is the only battery failure mode tht will fool a Midtronics tester.

Had the same problem on the 6 volt battery on the old 1949 Massey Harris 44, but it let us know by blowing the bottom out of the battery when it arced inside, setting off the hydrogen in the top of the cells.

That's 2 that I remember.

[clare]

At least one of the old ones I worked with didn't have a transformer because it was not isolated - you could get a nasty shock from the charging lead to ground. It had either a big wirewound rheostat or switched resistance. I seem to remember it being fully variable - which would have been either a rheostat or a powerstat (variable autotransformer)

[J Burns]

About 20 years ago I used a cheap analog movement, diodes, and resistors to make an 11-16V meter. It's fastened to the console in front of the gear shift and plugged into the lighter. It's much more precise and accurate than the one on the instrument panel, and I think seeing a needle position is better in this case than reading digits.

I infer charging current by the voltage with the lights off. If the battery is well charged, the current will be low and the voltage up around 14-15, depending on the temperature. I like to keep it well charged so I don't let sulfate remain on the plates indefinitely.

[philoÂÂ]

I also repair vacuum tube radios and get a kick out of some of those old advertisements showing someone lugging a 6v car battery down to their local service station.

Asking if you are sick of having to keep recharging your "filament" battery and tired of acid burns on the rug.

It was a for a "battery eliminator"

[micky]

I'm not saying this contradicts you but FWIW, the difference between a generator and an alternator was that alternators have higher output at low rpm than generators did.

That's why everyone switched, Most of them around 1964?? And that's why you can charge your battery while idling.

Used to be when the car idled, the red idiot light woudl come on that said "Battery" or something. With a generator the battery was discharging even thought the engine was running. Now you should be able to remove the battery and drive all over without it, as long as you don't turn off the car.

[micky]

You're probably right. Too late for me to tell.

But to add to this, it's the nature of batteries that they have almost full voltage weven when they are substatially discharged. The battery can be 80% discharged and still have iirc 90% or more of its max voltage. So you put those 1200 ampere seconds into the battery and you'll get them back at 11.3 volts, which is enough to start the car.

Someone showed me mathematically why the voltage stays so high, but I forget who, when, and why.

[micky]

It's amazing but they still make cars without that. Kmart used to sell and attachment for 2 or 3 dollars that only required 2 connections.

I don't think Kmart has it in the store, but googling in general should find one, probalby 10 dollars now.

I also recommend Priority Start and Battery Brain, which disconnect the battery when its voltage gets too low.

I had Battery Buddy for 20 years and it never failed to work, so I always could start the car, But they don't sell that anymore.

[micky]

At least a partial remedy for that AIUI is not to recharge ti too quickly. So I'll put the heater fan on high and the headliights on to lower the charge rate. When I had an ammeter in the dash, I could see that the rate was low.

So,

I used to charge my battery with a 1amp charger and it might take 2 days, 1 day just to put in enough to start the car, especially a 6 volt car. But I found on a sidewalk a 14-amp charger, and I've become a wastrel, so I charge it with that and the car is ready to start in 5 minutes. Positive to positive, negative to negative, red is positive, black is negative**. Plus embossed on the battery somewhere near the batttery posts, it says Pos and Neg. {Plus the cable that goes to the engine block is negative, but one can sometimes make a mistake following the cable along. ** (unlike house current where black is hot and white is neutral.)

[Pico Rico]

did you remember how?

[micky]

I've only replaced one alternator in 46 years and that one failed while the car was in a storage garage for 5 months (I'll never get to the bottom of that one.) And at least twice I've ruined my battery and I'll still go for 6 months or a year with the bad battery. Right now, the battery is ruined because the fob receiver was bad and kept draining my battery. Now the battery is so bad I can only play the radio for two minute before my Priority Start disconnnects it. After I use something electric in the car, like an interior ligh tor the brake lights, Priority Start resets in 5 or 10 seconds. and the car starts right up.

Another time I kept draining the battery because I had two burglar alarms installed at the same time. I thought the second one was an accessory that would beep me when the first went off, but it turned out that the second one used current all the time.

The brushes wore out on my 15-year old Lebaron convetible, and I thought I found replacments. But when I took the motor apart, the brushes fit but the woven copper leads on the replacement (from a hardware store) were much thinner than the original.

So I wadded up some aluminum foil and put it behind the brushes to push them further down the holder than the springs alone did. Wored fine for another 2 years, until the engine failed.

[micky]

What a great idea.

In 1958, I had a '50 Olds, that was 6V of course. It had a place on the other side for a second battery but I never thought about that.

But during the Chicago winter, I ran a long extension cord from the pantry window and every time I came home, I'd plug the 1amp battery charger into the cord. The charger itself was in the car somewher, with it's cord coming out the grill.

I kept it on 12votls and charged the car alll winter. It started every time except new years eve when it was about 0 degrees out. I called a tow and even he couldn't start the car that night.

The charger (I still have it but had to replace the selenium diodes) had a circuit breaker than looks like a long neon bulb (1/2 inch) and would trip every 30 seconds or so and reset 10 seconds later. I think that means about 15,000 times a week for 16 weeks or so, 240,000 times and it hasn't failed yet.