How to Charge RV Batteries With Generator?

The batteries are the heart of an RV. They power up most of its essential parts including awnings, stab jacks, lights, and even 110V appliances such as fridge, furnace, and so on.

But how do you get the RV camper batteries to charge? You generally charge them by plugging its power cord into a shore power such as an AC Electrical Grid. 

What if you’re out into the wild or a place where there’s no shore power available?!

In such instances, it’s the generator(a portable one) that you can use to charge RV batteries. But how?

Check this guide out here to know how to charge RV batteries with generator in the fastest and easiest way.

Can you charge a battery directly from a generator?

Yes, you can although a generator isn’t intended to charge an RV battery directly. It’s because a generator comes with a limited amperage which could make the charging process tedious.

Can you charge a battery directly from a generator

Also, your generator could be harmed. So using an intermediary battery charger is the best way for charging lithium batteries with generator for RV campers.

Fastest Ways to Charge RV Batteries With Generator

Let’s get into the core part now — how you can charge your RV batteries with a generator in the fastest (as well as safest and easiest)way. 

Fastest Ways to Charge RV Batteries With Generator

To take you through the complete procedure here’s our step-step guide below.

Get the Essentials for Fast Charging

To charge your RV batteries using a generator in the fastest way, you’ll need a few things. Most importantly a portable generator with an output of 2,000-watt and a triple-stage battery charger (with amps output from 45 to 80 amps).

Get the Essentials for Fast Charging

The more the output of the generator and the battery charger, the faster the batteries will charge.

You’ll also need alligator connection clips and a cleaning wire brush to clean the terminal points of the battery.

Take the Precautions & Preps

So here are some measures you need to take before you start charging the RV batteries with the generator.

  • Place the generator outside on a leveled surface and at least 3-feet away from any open windows or doors
  • Have a good understanding of the user manual and be familiar with all its controls, receptacles, and emergency stop procedure
  • Check the fuel level of your RV and make sure it’s full
  • Make sure the generator is fully charged and is able to work properly
  • Switch off your RV and engage its emergency brakes prior to checking the battery connections
  • Remove all the battery cables to check for any leaks in the battery
  • See if there’s any dirt build up in the battery terminals, use the wire brush to clean them with soda water
  • Allow the terminals to dry

Inspect Electrolyte Levels and Reconnect the Cables

Once you’ve done the preps and taken the precautions, it’s time to check the electrolyte level through its built-in indicator lights in the battery. If it seems low, pour in distilled water to get the level right.

Then reconnect your battery cables, positive ones followed by the negative ones. Once done, tighten the lid.

Inspect Electrolyte Levels and Reconnect the Cables

Turn off All Your RV Appliances

To make sure all the generator power is used solely to charge up the battery and not to hog up other appliances, turn off everything in your camper.

Turn off All Your RV Appliances

Inspect the Temperature

Check the temperature of your battery and make sure it’s below 40F. Otherwise, your battery’s maximum charge can quickly drain, something that you wouldn’t like.

Start Your Generator 

The starting method varies in different generator models. However, starting a generator to charge RV batteries will generally include the following steps-

Start Your Generator
  • Turn off the eco throttle switch first
  • Then switch on the fuel valve
  • Drag its choke to the ‘closed’ position
  • Then turn the key ‘On’
  • Now push the choke back again

Warm the Generator Up

Once you’ve started the generator, get it running for a few minutes. This will allow the generator to warm up. So you can see if everything’s right before you finally connect it to the battery or RVappliances.

Attach the Battery Charger

Now you should use the alligator clips to attach the battery charger to the terminals. Attach the red alligator to the positive battery terminal and the black one to the negative battery terminal.

Plugin the Charger into Generator

Your RV batteries can be charged on the generator power. However, we want you to avoid connecting the RV power cord directly to the generator. Instead, you’ll be using a three-stage or smart charger here.

Plugin the Charger into Generator

So if you’ve done everything right so far, you can now plug the battery’s charger into the 120V outlet of the generator. Turn the generator on and monitor the status of the charger by looking at its status light.

Turn the Charger Off

When you see the battery charge status is full, you can turn it off. And then unplug the charger from the generator. Disconnect the attached cables in the reverse order they were attached — negative clamp first followed by the positive clamp.

Now your RV batteries are charged and ready to power your RV and all appliances.

How Long Do I Need to Run My Generator to Charge RV Batteries?

Well, this is a supplementary question to the process we followed so far. You actually need to know how long it takes for a generator to charge your RV batteries.

Since we’re using a charger, the charging time will depend on the battery charger size or capacity. For a triple-stage charger with 50A capacity, the generator should take from 1 hour up to 5 hours to charge your RV batteries based on other underlying factors.

Run My Generator to Charge RV Batteries

Some of the other factors that determine the charging time include generator output (more the output, less the charging time required), number of appliances (more appliances will require more time), and the number of batteries (more batteries will require more time).

How Long Does It Take a 2000 Watt Generator to Charge a Battery?

If all the underlying factors are favorable, a 2000 watt generator should charge at 50 amps per hour. Since the 12V battery holds 100 amps, you’ll expect this generator to fully charge in an hour if it ran down to 50%.  

How Long Does It Take a 2000 Watt Generator to Charge a Battery

Similarly, a fully empty battery should be fully charged within 2 hours. But again, the charging time depends on a few other factors and you can expect the required time to be a little more than anticipated.

Fix – RV Battery Not Charging from Generator

If your RV battery isn’t be charging, it could be due to different possible underlying issues. Here we’ll discuss these possible issues along with their fixes. 

RV Battery Not Charging from Generator

Check & Fix the Connection

One common issue that affects charging speed could be the problem in the connection. The connection cables between the generator and the charger may have gotten detached or corroded. So make sure all the connections are fine or reattach if necessary.

Inspect & Fix the Alligator Clips

See whether you’ve connected the alligator clips properly — positive to positive and negative to negative. Check out the status light of the charger to know everything’s working right.

Add Distilled Water If the Fluid is Low

Deep cycle batteries may be low on fluid and could result in overheating while trying to recharge your RV batteries. Add some distilled water to get the fluid level into the right position.

Clean the Terminals

If the battery terminals have dirt buildup or have corroded, the battery won’t be charged. So clean them properly with soda water and a wire brush. Also, use a cloth to clean it entirely. You can also apply some petroleum jelly to avoid or delay future buildups.

Check & Fix If the Generator Has Issues

Sometimes the problem could be with the generator which is the power source in this case. See if there’s any problem with the generator fuse or the voltage regulator. If they’re worn out or damaged, you should get them replaced.

Final Verdict

There are a few ways to charge RV batteries with generators. But as far as this article is concerned we’ve focused on how to charge RV batteries with generator in the fastest possible way.

And we believe this could be a savior for campers, especially when you’re out in a remote place and running out of battery.  

While you’re charging your RV batteries, you are actually taking some kind of care of its batteries as well as its overall system. This allows you to go through routine maintenance for your RV. 

So while it’s a tedious procedure to recharge the batteries using a generator, it’s eventually a good one once in a while!