Battery/battery casing failure

[RupertW]

Hello all, 

I've noticed a battery in one of the box saloons has failed on the top and has split in several places as per the picture hopefully below. There's still plenty of fluid in the cells and a reading of 6.1v across the terminals which is obviously on the low side. Does anyone know what could have caused the failure? It may have been like it for a while.       

[richard wyatt]

My MGA uses a pair of 6volt batteries in series of the same type as yours;when I got my "A" out of long-term storage recently there were cracks on the top of the casings virtually identical to your picture. They retained electrolyte but only charged up very feebly so I have replaced them-MG Owners club seem to be the best buy. The brand name on mine is "Shield"and the tops look just like yours. I can only think of frost damage[of which I have heard but never seen]but I think that would be more catastrophic.A manufacturing fault perhaps? Mine way out of warranty anyway.Is yours the same make?

[RupertW]

Thanks that's interesting to hear you've had a similar issue. I'll double check what make it is, but shield sounds familiar. My only other thought was if it could be overcharging, but I'd think the fluid would have boiled off first? Also looks like these battery's have plenty of venting available

[Reckless Rat]

It looks just like a failure of the sealant between the cells. If the battery is OK and not leaking electrolyte I'd try a repair with some liquid rubber. I use the stuff that comes in a big cartridge, used with a mastic gun. It's great because it doesn't go off unless exposed to the air, unlike some mastics that set as soon as you've started the cartridge.

This is what I get in Macronland but I'm sure it's available over the Channel...

[Peter Naulls]

I had one with similar but smaller cracks. It still worked ok and the charging system didn't have any apparent problems. I assumed it was shrinkage of the plastic or sealant. I don't remember the make and it has since replaced due to old age.