How to Tell if Your Dead Battery Is Frozen—And Why That Matters

You turn the key and nothing happens. The thermometer reads 10°F and your dashboard is dead black. Your battery is either stone cold or frozen solid. One of those you can jump-start safely. The other can crack open and spray battery acid across your engine bay when you connect jumper cables.

The difference is visual. A cold battery sits flat in its tray and gives you dim dashboard lights or slow cranking when you turn the key. A frozen battery bulges at the sides or top because ice expansion has warped the plastic case.