MGB Register Forum

Hi all.
Sorry to regurgitate an old subject, but is the 063 12v battery still the best fit in an early car, or is there something better these days and is the twin 12v battery in parallel set up still a good idea?
Thanks 🙂

My mistake, I should have said 036!

Hi Adrian
I needed to replace the 6 volt batteries in my 74 B last year. After looking at the price of the 6 volt batteries I decide to look at fitting a single 12volt battery. I looked at the 063 batteries but in my search also came across the 202 battery. This is exactly the same size as one of the original 6 volt batteries. 190 mm high 175 v 175 mm square. 44AH, 420 Cranking current so more than enough to turn over an MGB.
I bought the Bosch S4 202 version from Eurocarpart. Around £80 with their discount code with a 4 year warranty. It’s available in 2 versions, depending on the terminal layout. Positive on left Negative on right or vice versa. I chose the positive on the right for better access to the main battery lead. Since fitting the car has never cranked so well in all it life and an added bonus the indicators work at tick over so I think it is not necessary to fit 2 batteries.
Best regards
Mike Barclay

Excellent Michael thanks, I'll order one 👍

Michael, the AH rating for that Bosch battery is quite a bit lower than the standard and heavy duty batteries normally fitted to MGBs? Would that be any problem?

Ian F

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Went for this Yuasa in the end, plenty of punch for £52.99 🙂

Hi Ian
Yes you are correct the AH of the 12V battery is lower than the standard 6 v batteries. The MGB is very simple when it comes to electrics so the electrical load is quite light, unlike modern cars with all their power zapping electronics to drain the battery. The more important figure is the cranking current as this will determine how much power (and voltage drop) the battery can supply when the starter motor is engaged. I have owned my car for 42 years and have replaced the 6 v batteries several times in my ownership. In all that time, the engine has never turned over with such enthusiasm with the 12 volt battery and for the first time the indicators flash on tick over. The Battery has been in for just about one year now and not given any reason for concern. In fact taking the picture of the battery was the first time I have removed the battery cover since fitting.
Another bonus was no massive verdigris balls covering the positive terminals.
Best regards
Mike Barclay