How to Change a Car Battery Without Losing Power

by Don Patton

Today's cars have a number of circuits that require continuous power. If the sound system loses power, preset radio station tuning will be lost and the clock will have to be reset. There may even be a security lockout that keeps the sound system from operating until it is reinitialized with a secret code. Settings for the car’s remote entry system may also need to be re-entered if the battery is disconnected. These problems can be avoided if you use a portable jump starter as a substitute power source while replacing the battery.


Make sure the car ignition is turned off. Remove the keys from the ignition to be sure.


Set the jump starter power switch to the "Off" position.


Connect the positive (red) cable of the jump starter to the positive clamp that is connected to the terminal of the battery to be removed. Connect it so as to not interfere with the loosening and removal of the battery clamp from the terminal.


Connect the negative (black) clamp to the car’s chassis or a solid non-moving metal component or body part.


Turn the jump starter power switch to "On."


Using the wrench, loosen the bolt that holds the positive clamp on the terminal of the battery you're replacing. Slide the cable clamp off the terminal and place it away from the battery. Make sure the clamp does not come in contact with any grounded metal parts of the vehicle. Wrap it in a towel or rag to provide insulation from surrounding parts.


Loosen the negative clamp and remove it from the terminal in the same manner.


Firmly grasp the old battery and lift it from the vehicle.


Position the new battery in the vehicle battery area.


Position the positive cable clamp on the positive terminal of the new battery. Carefully tighten the clamp hardware with the wrench.


Position and connect the negative clamp to its terminal in the same way.


Turn the jump starter power switch to "Off."


Disconnect the jump starter clamps from the battery terminals and clamps.


  • check Unlike the positive clamp, the negative clamp does not need to be insulated while the new battery is installed.


  • close This procedure is intended for vehicles with 12-volt negative ground electrical systems only.
  • close Batteries can generate explosive vapors, so always work in a well-ventilated area. Never clamp directly to both battery terminals as sparks could cause an explosion.
  • close Batteries contain acid. Be very careful when working with batteries; wear gloves and safety glasses.

Items you will need

About the Author

Don Patton began writing after retiring from an engineering career in 2006. He holds a Bachelor of Science in electrical engineering from the University of California at Berkeley and continued with graduate study in software engineering.

More Articles

Photo Credits

  • photo_camera Thinkstock Images/Comstock/Getty Images