Replace a Car Battery
Test, remove, and replace a dead or weak car battery safely, including terminal cleaning and proper installation.
Tools Needed
Find Materials Near You
Tap a store to find the nearest location on Google Maps.
Instructions
Test the Battery
Use a battery load tester — most auto parts stores test for free. A healthy battery reads 12.6V at rest. Below 12.2V or failing a load test means replacement.
Turn Off the Vehicle
Turn off the car and all accessories. Note any radio codes you may need to re-enter after disconnecting power.
Disconnect Negative First
ALWAYS disconnect the negative (black, -) terminal first. Loosen the clamp bolt and wiggle free. Then disconnect positive (red, +).
Remove the Battery
Remove the battery hold-down bracket. Lift out the old battery — they typically weigh 40-60 lbs. Keep it upright to avoid spilling acid.
Clean the Terminals
Use a battery terminal brush or baking soda paste to clean corrosion from the cable clamps and battery tray.
Install the New Battery
Set the new battery in the tray. Reinstall the hold-down bracket. Connect POSITIVE first, then negative. Apply terminal protector spray or grease. Test start the vehicle.
