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MG MGB Technical - Jumpstarting/charging twin 6V batteries

This is a very trivial question I am sure, but what is the correct way to jump twin 6V batteries, negative grounded 74B?. Also is it possible to charge both at the same time in situ?

I have never had to perform this on twin 6V batteries and a thus a little weary!

GG Ginty

I wouldn't risk jump-starting a B, just because the crocodile clips will be really close to the bodywork! However, in theory, you can do it by connecting to the outside negative of one battery, and the outside positive of the other (i.e. the two terminals that aren't directly connected together).

Think of the batteries as one, big battery: they're connected in series, so you can treat them as one battery made of two cells.

I think, in theory, you can charge in the same way, although you should never charge batteries while they're installed. Having said that, I do trickle charge mine in situ, with a battery conditioner connected to the cigarette lighter...
D Ainsworth

Connect your positive jumper cable to the main stud on the starter solenoid and the negitive cable to the engine block rather then at the battery. You can add a copper tab to the solenoid conection to make this eaiser. you can also run a short heavy cable form the solenoid to a post on an insulator in a convenient spot to connect your cable. This is getting common on new cars as they bury the battery under other components. You can charge them both at once in series as a 12 volt battery. I wouldn't exceed a 6 amp charger if the batteries are not removed from the car.
John H

A 12-volt battery is really 6 2-volt cells connected in series. In your case, there is a bigger separation between two of the cells than there is in my Spridget's battery, but so what? John's suggestions are good.
David "a single 12-volt Interstate battery is stronger than most pairs of the 6-volt batteries available today" Lieb
David Lieb

This thread was discussed on 02/10/2008

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