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MG MGB Technical - Conversion to single 12v battery

Anyone succesfully converted their B to a single 12 volt battery? If so, some details would be appreciated.

Sorry if this has been covered before, I have searched both the Live BBS and Archive but cant find anything.

Dave P


I have converted both my Bs to 12v batteries using a standard 063 pattern battery. I have actually fitted them in the passengers side but others have claimed to have fitted them in the drivers side although there is an intrusion there by the fuel pump. If you fit in the passengers side you will have to extend the stsrter cable by fitting a joining sleeve covered with shrink film material. To fit the 063 it has to be lowered at an angle, use a belt round the battery to lower it and withdraw after fitting. You will also have to adapt the battery clamps but can get suitable items in a breaker's yard and adapt quite easily. I have used the 063 for ten years now and have had no problems with plenty of cold cranking current
Iain MacKintosh

Dave, try searching 12v in the archives. Then scroll down to 12v and also battery and you will find lots of info. I have a chrome B converted to 1 battery it is fitted to right hand side behind the driver RHD car. This picks up the original battery cable to the motor and is also the same side the rubber nose cars have there 12v battery fitted. Consider fitting a battery isolating switch at the same time.
K Stuckey

a varta b35 battery fits perfectly in a 6v battery cage and also fits in the plastic battery box with no cutting at all.

Ste Brown

I'm planning to fit a B35 myself.

As you can see, the footprint is the same as a 6v, but it is slightly shorter.

Dave O'Neill2

I fitted two 12v batteries, there is quite some ooomph there when I turn the key.

John Prewer

Get one with a handle in the top if you can. That makes extracting it later much much easier!

Mike Standring

Hi dave,
I converted my car to 12 v found a battery that fits the original box.
I got the battery at a uni part outlet prt,no UGCGBA4063 this battery is a tight fit but dose has a handle to pull it out, also the battery has more plates than the standard battery built into this case and therefore more cranking amps. I've found this battery turns the engine over a lot faster than two 6 v batteries.

Regards Patrick
P.T. Tighe

Thanks for all the replies, I knew I could rely on you guys!
Dave P

This thread was discussed between 29/01/2013 and 30/01/2013

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