How do you know if your car battery is bad or if it just needs a charge?

Answer by  tkarlav (1502)

you cant tell . what you need to do is have the battery tested . during the test they put the battery under loads to see if the battery can handle the power loss and recover in an aloted amount of time.if it cant it fails and needs to be replaced.or charge it and see if it dies quickly

Answer by  foxstang (133)

The battery should be load tested. This test will show if the battery has the capacity to retain a high enough voltage under a load, similar to what a starter would place on the battery. If it passes the load test, it simply needs a charge. If it fails, it needs to be replaced.

Answer by  Amber40 (24961)

You could simple use a battery charger and fully charge it then let it sit. If it can sit all night unhooked from the car then start it the next day with no problem then it should be fine. You can also have most parts stores or dealers run tests to check the condition of the battery.

Answer by  Crumudgeon (66)

The battery can be tested. Batteries charge while the car is being driven, so it should always be charged. If it works poorly often it is probably bad.