My friend used to run an 8v battery with his 6v pos ground system without changing anything. It worked good. Are there any problems with this?

 

I've heard of people doing this too. I would just make sure the generator was putting out enough to charge the battery. I would say you probably should read about 9 volts at the battery when charging. If you are reading 8v or lower, I would take it to an auto elec shop and find an old guy who knows what he is doing. He should be able to turn the regulator up a little bit.

 

What he has is not an 8 volt but a 9 volt battery. I used to have one a long time ago in an old chevy. For a while. You tweak the voltage regulator up a bit to get enough charge for the 9 volt battery (more like 10 volts if you can get it). It works in that it will turn the engine over faster for easier starting. An absolute pain, however, when it comes to burning out headlights and taillights. I don't imagine that it is very good for the gauges either. The lights burn real bright, for a while, but get used to buying them at Walmart by the case and carrying spares around with you. I got rid of the 9 volt battery. Better to spend your money to fix your 6 volt system so that it works correctly or convert to 12 volts.

 

Well, I kinda hate to admit it but I have an 8V system in my 1949 F1 and I thought I was the only one on the planet. The previous owner bought the battery at the local battery shop (special order?) and also a new 8V regulator. (1 month before I bought it.) His logic was if 6 was good, then 8 was better. For the last two months absolutely everyone gave me a blank stare when I described it until yesterday. One guy says "Oh yes, the military used 8V systems in their jeeps for the same reason. I don't know if he's right but he seemed to know of which he spoke. It sits at about 8.3V and charges at about 9.1V One of my Ford books lists the bulb live vs. voltage. At 6.1V a typical bulb lasts 3300 hr. At 7.3V it's 322 Hr and at 8.1 it's 87 hours! (This was under troubleshooting: "One or more bulbs burn out repeatedly.") I don't have enough hours to have had a problem yet. My gages are all screwed up, probably due to this and other problems. Haven't got to them yet. Think of this, if it dies, what are you going to do. My charger is 6v or 12V. Maybe I can get a jeep to jump me. I am very careful to turn the lights off. Eventually I will go back to 6V or make the jump to 12V. Probably 12V which is common and seems pretty easy. Good Luck, Johann

 

Sorry about questioning 8 volts. I guess you learn something new every day. I didn't think there was such a thing as an 8 volt battery. The way I always understood it was that each cell in a battery put out 1.5 volts (just like one C-cell). So, you ended up with batteries that were combinations of 1.5 volts. Six volt batteries had 4 cells, 12 volt 8 and 9 volt had 6 cells. How you ended up with 8 volts is a mystery to me but there is always something new I haven't heard.

The number of cells times 1.5 volts is not quite accurate. Even a 12 volt battery has more the 12 volts at rest. Closer to 12.5 volts if a recall.

Is your battery a conventional automotive battery? How many cells does it have? Could it be a 9 volt that isn't fully charged? A healthy 7.5 volt battery?

 

I think a car battery is closer to 2 volts per cell. That's why 12 volt batteries have six caps (in the old days). Some of the caps that you can still get off have two large caps with three cells each underneath. Of course an 8v battery would have four caps or cells.

 

Absolutely everyone, except the last guy I mentioned, said exactly the same thing. "I have never heard of an 8V battery." It is a standard automotive 8V and has 4 cells. Lead/acid batteries are about 2.1V per cell, depending on how charged they are.
Johann

 

Johann5,

Sorry, Your right, I was wrong. Memory has failed me. 2 volts per automotive cell makes 8 volts. It was an 8 volt battery that I had and not 9 volts. Guess I've been replacing the battery in to many smoke detectors. Still, we agree. The extra voltage does shorten bulb life.

 

Where the 8 volt battery is most commonly used this day and time is in heavy equipment where lots of amps are needed and 3 - 8volt batteries are put in series for a total of 24 volts. They tend to be more robust than the modern 6 volt battery for just this reason. many over the road trucks use 8 volt batteries in series. Hope this helps...

 

All this talk about batteries is making me dizzy. It reminds me of an old CHEERS episode. Next thing you know I'll be trying to test my house circuits with a battery tester and blow myself up.
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