How to Hardwire a Power Inverter to a Battery

by Joe Murray
Power Pack image by Cinneman from

Power inverters convert 12-volt, direct-current to 110-120 volt, alternating-current. They are generally used in automotive and marine applications to power appliances, computers, TVs and similar 120 AC devices. Power inverters come in a wide selection of wattage, from 100 to more than 1000 watts. Hard wiring a power inverter to the vehicle or source battery is recommended for wattage over 350.

Step 1

Measure the distance from the battery to the chosen location of the power inverter. The distance should be as short as possible.

Step 2

Mount the fuse holder between the battery and the power inverter location. Situate the fuse holder as far from any heat source as possible, without compromising the length of the wire.

Step 3

Run the wire from the battery location to the fuse and from the fuse to the power inverter location. Secure the wire with wire ties and electrical tape to whatever permanent medium is in the installation location.

Step 4

Mount the power inverter making certain all grounding instructions accompanying the unit are followed.

Mount the power inverter, making certain all grounding instructions accompanying the unit are followed.


  • Read the power inverter instructions thoroughly. Installation procedures vary with brand and power usage. Remember the power inverter drains current directly from the battery. Don't over-tax the battery without charging it.


  • Cover the wiring with plastic conduit cover if installation will be exposed to weather. For correct fuse amperage, divide the total wattage of your power inverter by 11 and round up to the next whole number.
  • Many power inverters come with a battery isolation switch. If not so equipped, isolate the power inverter from the battery by installing a battery isolator switch in line with the positive lead between the fuse and the power inverter. When installing a high wattage power inverter for multi-purpose use, it might be best to install a three-prong dual outlet in an outlet box mounted in a convenient location.


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About the Author

Joe Murray began writing professionally in 1980. As a technical writer, he authored white papers and articles for Hewlett Packard and Intel. Since retiring, Murray has written several home-exchange travel articles for and CHECtravel,com among other outlets. He holds a bachelor's degree in philosophy from Santa Clara University.

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