How to Tell If a Car Battery Is Weak?

Your car's battery runs the electrical system and triggers the starter. Recharge a battery that has been drained through leaving the lights on or the alarm running. Replace older batteries that have become weak and are unable to hold an adequate charge. There are a few steps you can take to tell whether your battery is weak.

Instructions

1. Start the car. If it sounds like it's struggling to start or stay running, makes a clicking sound but doesn't start or doesn't make any noise, you've got a weak or dead battery.

2. Turn on the headlights. If the headlights are unusually dim or are slowly fading from bright to dim, you probably have a weak battery.

3. Test it. Buy your own battery tester--available at automotive stores--to test the charge yourself or take your car to an auto mechanic. Mechanics will generally test your battery for free. If the battery is not too old and simply has a low charge, they may recharge it for you.

Tips & Warnings

• Check your warranty. If the battery has gone bad within the warranty period, you may be entitled to a replacement.

• A car with a drained battery can be restarted with jumper cables. It can then be recharged by driving around for a half-hour with no electrical accessories turned on.

• If you know your battery is good but it still seems weak, make sure the battery and cable terminals are properly connected, clean and in good condition.

References

• automechanics.wordpress.com: How to Recharge a Dead Battery
• edmunds.com: A Shocking Expose: Your Car's Battery