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rv trips & travel

How To Charge An RV Battery With A Generator

RV’s are pretty flexible. Using a battery, gas engine, or shore power through an inverter, they can find power just about anywhere. RVs could use power just about anywhere, too.

The battery does need recharging once in a while to keep up with the need to start the vehicle and power many of the appliances inside. Thankfully, like a regular vehicle, an RV can be charged with a generator. Most RVs also at least have a place for a generator if they don’t come with one. 

Your RV battery can be charged with a generator. Genreally, running the generator while connecting it either to your battery terminals or external plug ins will help recharge your battery. Generators can be very convenient when other options aren’t available though we’ll review some safety thoughts too.

Getting started with charging the RV battery with a generator

First, you’ll want to prepare your generator and ensure it can charge. To charge relatively quickly, you’ll want your generator to be at least 3500 watts. This will help charge batteries without waiting all day or wasting gas.

  • Keep your generator at least a few feet from the RV itself. Generators can be loud
  • Ensure the RV is level and on a level surface. A generator vibrates and can move.
  • Put enough gas in the generator. Be sure to follow the instructions on the generator in regards to what type of fuel to use and whether or not to fix in oil
  • Start the generator using the pull cord or switch
  • Let the generator run for a few minutes, adjusting the choke and other starting switches as necessary. Once the generator is “warmed up” it’s more ready to produce electricity efficiently.

Your RV might have a built in generator somewhere in an exterior compartment. Built ins are generally easier to start as they came designed for the motorhome.

Connecting with an input 

Some RVs have an exterior outlet, or inverter, that brings electricity from the generator or “shore power” and powers the RV while charging the battery.

  1. Find an extension cord. You’ll need one to run from the RV generator to your inverter
  2. Plug the extension cord into the generator first
  3. Plug the other end into the inverter
  4. You may have a meter somewhere inside your RV that indicates if the battery is charging. Ensure this indicator is showing the battery charge.
  5. The question of how long depends on the power of the generator and the size of the battery.
  6. Once the generator is finished charging the battery, turn the generator off.
  7. Unplug the power cords from the RV and from the generator.
  8. Put the generator away.

Connecting to battery terminals

RVs also often have the option or requirement to connect a charger to the battery terminals.

The setup regarding the generator itself is the same in terms of safety.

Generators often come with a connection that uses a traditional household outlet but converts to the clamps you often see on jumper cables. Others have terminals (the copper posts) to clamp jumper cables onto.

  1. Locate the battery within your RV. The placement does depend on the RV. It might be in the back, in a compartment in the floor, under the stairs, or under the hood.
  2. Move the generator to a place where it more easily reaches the battery, if you need to.
  3. Start the generator and let it warm up for a moment.
  4. Connect the jumper cables to the generator itself. Connect black to black and red to red. Start with black first, then move to red. You can try this in different orders. We suggest keeping the red end away from metal once you connect it to the generator itself.
  5. Remove the terminal caps from the battery, if it has any. These might be exposed.
  6. Get the clamps over the battery. Connect the black clamp to the black terminal. This is your ground cable and doesn’t send electricity.
  7. Connect the red clamp. Be careful not to touch any metal within your RV besides the terminal. Thankfully, most items should be plastic.
  8. Ensure the connections are secure. Wait a while and see how the meter on your battery is doing.
  9. Once the battery is done charging, turn off the generator. With the power off, the disconnect order of your cables won’t matter.

RVs with internal generators

If you have an internal generator, you might not need to do much! This generators come with a connection to the battery and other appliances. There may be a switch to decide between internal power and battery power. Use this switch to start the generator and have it send power to the battery. 

This is the easiest method. 

How long will it take?

The answer depends entirely on the size of the generator and the capacity and level of the battery. We recommend at least a 2000 watt generator to charge a battery in less than a couple hours.

A smaller generator can take hours longer.

Why charge on the generator?

There may a time when your battery needs a charge and you are not near a good power source. A generator can definitely help get your battery back in shape in a matter of less than a few hours.

For people who are camping off the grip a bit, generators can be very helpful. So long as you can get enough gasoline to keep a generator running, you’ll be fine to run appliances and your RV so long as you keep an eye on the carge.


Setting your generator up to charge your RV depends on whether you are using cables and a built in generator. Read our instructions above to charge your batter in a safe, easy, and efficient way. Generators can be very helpful if you want to avoid having to go to an RV park or there isn’t one nearby.

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