Originally Posted by
rumrunn6
was reading safety warnings for a car battery charger I got yesterday. one of the warnings was never charge a frozen battery. they didn't say why but there's probably a good reason. was gonna take it out of my kids car, bring it inside to charge it overnite. but the warnings about gas clouds & explosions, etc had me doubting the idea. eventually my mechanic said he'd go check it out & it was probably the starter anyway
Car batteries throw off hydrogen gas while charging, but if you're doing it in a well-ventilated area and not making sparks (like moving the cable clamps unnecessarily) you shouldn't have much to worry about. If your battery has gotten low enough to freeze (I had one that was literally bulging years ago), there's a chance your alternator isn't up to snuff anymore, either.