Frozen Battery?

[Lumatic]

One more battery question.

My not too new but very very dead 200 amp AGM battery has zero output. It got down to 35 below last winter and I have not used it since. Could it have frozen?

[Alumaholic]

Hi Lumatic. Did it have a full charge before we had the cold weather? Though AGM batteries are supposed to survive "most freezes," I suspect an AGM with a depleted charge would still be vulnerable to freezing whereas an AGM with a full charge would be impervious.
Lookin' forward to the Punkin' Chunkin'

[Lumatic]

Some charge but not a full charge.

[Wabbiteer]

"AGM batteries can withstand freezing - you will get little or no output from a frozen battery, but at least it will not ruin the battery or break the case." www.windsun.com

[Lumatic]

Originally Posted by Wabbiteer

"AGM batteries can withstand freezing - you will get little or no output from a frozen battery, but at least it will not ruin the battery or break the case." www.windsun.com

Not sure if she froze or not. But definitely thawed by now. And dead!

[Nuvite-F]

Did you say 35 below?! I'll bet it froze. I have had two ordinary wet batteries freeze over the years in little-used vehicles and once they've frozen all they're good for is trade-ins. The cases didn't split--they looked OK, but they were shot. I wouldn't be surprised if a good freezing doesn't displace the plates enough to break some connections, AGM or not.

With batteries as expensive as they are now I have learned that the little battery charger/maintainers are a good investment.
.