Q: Can a Car Battery Freeze?

A new or nearly new car battery in most of today’s vehicles is fully charged if the voltage is at about 12.6 volts. When a battery starts to age the voltage that it can store will start to be less and less until the battery cannot hold a charge at an acceptable level for the automotive systems to operate correctly.

A fully charged battery of 12.6 volts should be able to withstand a cold temperature of about -76 degrees Fahrenheit. The battery can lose about 30 percent of its power when the temperature falls to 32 degrees F and can lose 50 percent when the temperature falls below freezing. A fully charged battery can withstand the temperature about 12 to 24 hours and then will start to drop power until the temperature drop kills the battery and it will freeze.

If you keep a small trickle charge going into the battery during freezing temperatures, it will help keep the battery warmer and help prevent freezing the battery. To help protect your battery from the below freezing temperatures you could keep the vehicle inside a garage along with keeping it fully charged. When the battery is below 100 percent charged, the battery electrolyte can start freezing at 32 degrees F.

If a battery freezes then the battery case may swell and crack. A cracked case will leak out all or most of the electrolyte fluid when the temperature warms. This will cause battery acid damage to the area of the spill and you will need to have the battery replaced. If the battery did not crack yet, allow the battery to thaw completely, then recharge and test it before use.

Winterizing your battery by having the cables cleaned and tested will help prevent problems with the battery when the temperature starts to drop in your area or where you are going. If the battery is weak or failing, then have it replaced now before it leaves you stranded.