How to Hook Up a Power Inverter to a Battery

By:Michael Johns

hooking up inverter to battery

Hooking up an inverter to a battery can be a little intimidating if you’ve never done it before.

But don’t worry, it’s actually a pretty simple process once you understand the steps involved. 

Once you have your inverter connected to your vehicle or deep cycles battery you’ll safely be able to access off-grid power anywhere, anytime.

In this article, I have written a simple and easy-to-follow outline of how to install your power inverter in either a temporary or permanent setup. Take the time to read the information and consider all the points before starting your installation. 

If at any point you are not sure of what you are doing, I would advise you to consult a professional. 

Temporary Inverter Connection to Battery

First I will go through the process for a temporary connection if you want to use a portable inverter with a car or other off-grid battery source. If you want to mount an inverter in place for long-term use, I suggest you follow the steps for a permanent connection that will be safer and more secure.

For a temporary connection, you won’t need many tools. All you’ll really need is your inverter, alligator clips, and a battery. 

  1. Ensure your alligator clip cables are securely fastened to your inverter terminals. Red/positive to red/positive and black/negative to black/negative. If you bought these cables separately, ensure they are the correct gauge/size for your inverter. This information should be in the user manual or compare to cables that arrived with the inverter.
  1. Identify the red/positive and black/negative terminals on your battery. This is where you will connect your alligator clips.
  1. Using the alligator clip, connect the black/negative inverter cable to the black/negative battery terminal
  1. Using the alligator clip, connect the red/positive inverter cable to the red/positive battery terminal.
  1. Ensure the alligator clips are secure and have a snug connection to the metal battery terminals.
  1. Switch on your inverter to check all systems are running correctly – Usually, a green LED light will turn on if everything is running correctly. If you are hooked up to your vehicle starter battery always ensure the engine is running while the inverter is in use. Otherwise, you will quickly exhaust your battery leaving you unable to start your engine.
  1. You can now plug in your appliances to make sure you can draw power.

Permanent Inverter Connection to Battery

What you’ll need:

  • Wire strippers
  • Pliers
  • Screwdriver
  • Spanners/wrench
  • Inverter
  • Fuse/circuit breaker with cable and lugs

1. Mount Power Inverter in Position

The first step is to mount your inverter in a suitable position. It’s always best to place it as near to the inverter as possible to keep connection cables as short as possible. The longer the cable the more the voltage will drop and the less efficient your inverter will be.

Most inverters over 500 watts should have a mounting plate included in the shell. To it is just a case of drilling corresponding holes and screwing into place. Make sure you place it in a dry well-ventilated area to allow cooling systems to work properly.

2. Install a Fuse (Recommended) 

Not everyone adds an in-line fuse to their inverter. Modern products usually include in-built fuses to keep you safe. But this will not protect the cables between the inverter and the battery. If these were to short circuit or become exposed it would present a fire risk. So it is highly recommended to add an in-line fuse between the inverter and battery. You should refer to the manual for recommended cable and fuse sizes. You should match what the inverter already uses. Here’s how to add your fuse

  1. Find a spot close to the battery to install the fuse. This should be within 18 inches on the positive wire.
  2. Using the correct AWG cables strip the ends you want to connect to the fuse. End from the inverter side and one end from the battery side. Some inverters come with cables already attached so you could cut and insert your fuse into this cable.
  3. Add connective lugs to the two freshly stripped cable ends.
  4. Crimp the lugs onto the wire so you get a snug connection
  5. Finish with electrical tape leaving just the O-ring of the lug exposed.
  6. Screw these two cables and lugs into each end of the fuse.

If you prefer a video explanation watch this great tutorial:

3. Grounding Wire if Needed

Next, you might need to add a grounding wire. If you are connecting to a vehicle starter battery this is included in the negative battery terminal so you can skip this step.

You should see a small grounding terminal to connect a ground wire to on the inverter. You then need to run the other end onto the bare metal of the vehicle body. Or outside of a vehicle to a metal post into the ground.

4. Connect the Negative

Now we can start hooking up the inverter to your battery. This can be made easier by using O-rings to hook over the battery terminal. Start by connecting the black/negative cable to the black/negative battery terminal. Then tighten with the battery terminal nut to secure it in place.

5. Connect the Positive

Next, you can do the same with the red/positive cable to the red/positive battery terminal. Once again fasten in place to ensure a snug connection between the metal surfaces.

6. Check operation

Everything should now be connected. You can double-check and tighten all your connections to ensure they are snug.

Try switching on your power inverter. Usually, a green LED light should signal that everything is working correctly. If this is the case, plug-in an appliance to see if you can draw power to your electronics.

Safety Tips for How to Hook Up an Inverter to Battery

  • Engine off – If you are connecting your inverter to a vehicle starter battery ensure the engine is switched off before you start any work.
  • Disconnect positive – When making any adjustments or maintenance disconnect the positive cable to break the circuit to avoid short circuits and electricution. 
  • Avoid bad weather or rain – Power inverters and batteries should never be exposed to rain or water. This instantly damages your equipment.
  • Not under the influence – Avoid working on your circuit after you have been drinking alcohol as this can lead to mistakes.
  • Check the manual for details – If you’re not sure about technical information, refer to your user manual or contact the manufacturer for correct specifications.
  • Remove metal jewelry – Take off items like rings and watches as they conduct electricity.

Do Inverters Come with Fuses?

Yes, most new power inverters now come with in-built fuses. This is great as it protects your inverter and appliances from things like power surges and short circuits. 

The in-built fuse will not protect the cables between the battery and inverter.

Do You Need a Fuse Between Battery and Inverter?

A fuse between the battery and inverter is highly recommended. It will protect the cables running from the battery to the inverter. Without an in-line fuse here you will have a safety risk. Should the wires become exposed and create a short circuit there will be nothing to trip the power which creates a fire hazard.

Fuse to hook up inverter to battery
In-line fuse between inverter and battery

Final Words on Hooking Up an Inverter to a Battery

Once you understand the different components it becomes a lot easier to work out how to hook up an inverter to a battery.

If you have a portable inverter you want to use temporarily you can quickly connect using alligator clips. Quite often, these are supplied with lower-powered products like 500 watt and 400 watt inverters.

On the other hand, permanent inverter installation requires a little more attention as you need to be more aware of safety risks. You should consider adding an in-line fuse to your battery and inverter.

The above guide is an outline of how to hook up an inverter to a battery. You should take the time to check your own equipment and read user manuals before attempting your installation. If you are not sure, then consult a professional to help you.