Battery Basics - Car Won't Start

Your car won't start?

When your car won't start, you might jump to the conclusion that you have a dead battery. You should realize something else could be the culprit.

Your battery could also be discharged, which simply means it needs recharging. Check around to see what may be causing the battery to discharge.

Has your car been sitting for a long time? If so, the battery may discharge by itself.
Are there drains on your battery when your car is turned off? Check accessories including cell phones, radar detectors, GPS, TV, or computers. Even car alarms can impact your battery.
Have you left your headlights, dome light, glove box light, or trunk light on for a long period of time? That can cause an excessive drain on your battery.
Is it extremely hot or extremely cold? Both high and low temperatures can take their toll on the battery's charge.
Is there an electrical short anywhere in the vehicle?
Have you modified your vehicle with air conditioning, power boosters, advertising signs, or additional radios?

The problem could also rest in something around your battery.

Are your terminals or battery clamp corroded? If so, your battery won't charge properly.
Is there a loose ground wire giving you an intermittent connection?
Do you have a cross-threaded bolt on your side terminal? That could cause a loose connection.
Is there a loose or worn belt? That can make your battery work too hard.
Is your voltage regulator functioning? If not, your battery could overcharge or undercharge. You should also check your battery for related problems.
Is your battery installed correctly? An improper holddown or a lack of holddown can cause excessive vibration and internal damage to the battery.
Do you have the right battery size? If your battery is too small for your vehicle, it may not function correctly.