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r/MechanicAdvice•
JakeBake

Safe to jump start a car that has been sitting in freezing temperatures for weeks?

Hi all,

My girlfriend left her car sitting for 2-3 weeks in freezing Canadian temperatures. I've never jump started a car before, but after a bit of googling, I'm going to do it. One thing I've come across while researching is that it is not safe to jump start a frozen battery.

I'm wondering if it is safe to try jump starting the battery when it has been sitting in the conditions I previously described... Sorry if it's a stupid question.

If it matters, her car is a 2012 Toyota Yaris and mine is a 2005 Corolla CE.

Thanks for any advice.

Posted Feb 20, 2021, 5:04 PM UTC

46
Tired_of_yer_ish•

Basically if its not bulging out in any way it should be good.

If you have concerns about the electrolyte being frozen, bring it inside and let it thaw out. It won't harm anything to disconnect the battery and bring it inside for a few hours or overnight even.

8
JakeBakeOP•

I guess bulging will be fairly obvious to see without disconnecting it? Thanks for the advice

3
Tired_of_yer_ish•

Yes, but be highly critical, even a little bend is a bulge. Bulging indicates short circuiting. If you bulge, plan on replacing even if you get the car running. It's not unknown to push a battery with a bulge and it literally explodes.

3
metalhair307•

Can you pull the battery out and take it inside for a few hours? A frozen battery will show signs of stress. If it is frozen it will be bloated/swollen. Try warming it up first

5
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1
Kumanogi•

I don't know much, but my car's battery was completely drained (didn't use it for months) and the weather has been a bit cold over the past few months (California, so not freezing cold, around 40f at its lowest). Battery wouldn't charge at all and my jumpstarter didn't even detect it. Took it to autozone to get it tested and yup, its faulty. No bulging or anything though. Battery was around 7 months old, so I just took it back and replaced it under warranty.

So what I'm saying is, if you don't have anything to test it/jump it with you might save some time and just take it to the nearest autozone for a free charge and test. 😅

1