How to Charge RV Battery with Generator?

rv battery

Every RV owner including me at some point has suffered from dead batteries regardless of the cause. If you are at an isolated location with no access to shore power and suddenly your battery dies, there is hope. Your generator can charge the battery. A 12V RV battery is the most critical part of the vehicle. Virtually everything from lights to fans works on the battery. It is crucial to know these small DIY ideas if you want to live an outdoor life.

Can I Charge My RV Battery With a Generator?

An RV Battery can be charged using a generator. To do so, you have to check the fuel level and filter of the generator, terminals, and electrolytes of the RV battery, switch off all the appliances in your RV, plug the generator firmly with the battery, start the generator and allow the battery to charge for 3 to 4 hours.

Steps To Charge an RV Battery Using a Generator:

  1. Inspect the Generator
  2. Before using the generator power, make sure to check the oil, fuel, air filter, and carburetor. Sudden power surges may cause damage to the

    battery. If you have a dual fuel generator make sure to test on propane as well sometime a faulty house causes extreme voltage fluctuations.

    Start the generator, and let it run for a few minutes.

  3. Check the Terminals
  4. Make sure that battery terminals don't have corrosions. White, yellow, or green fuzzy stuff is the identification of corrosion.

    Clean it with wet baking soda and an old toothbrush immediately because it also prevents the battery from starting. Also, check the battery fluid (or water) in each cell. Lack of no water at all can also kill the battery. If your battery fluids are low, pour some distilled water until it reaches

    the fill line. Before using the generator, make sure you have gone through the above-mentioned steps. Maybe there is something wrong with your battery, so instead of going through the trouble, make sure your battery is fine and only out of charge.

  5. Turn OFF Everything in your Rv
  6. If your generator is directly wired into your electrical system, make sure everything is turned off including the lights to drive as much power as

    possible to the battery. Temperature also plays a role. If your battery has a good BMS (battery management system), then you might be able to properly charge the battery even if the temperature is above 40 degrees or cold. Otherwise, it might limit the maximum charge a battery can hold.

  7. Attach the Battery Charger
  8. Using the alligator clips, attach the battery charger to the battery terminals. Red clips are for the positive (+ve) terminal, and the black clips are for the negative (-ve) terminal.

  9. Plug the Battery Charger into the Generator
  10. Plug the battery charger into the 120V outlet of the generator. Let it charge for a few hours.

  11. Remove the Plug
  12. Remove the battery charger from the generator then turn it OFF. Never turn OFF the generator while the battery is still being charged.

    Attach the battery to its place. It might be running now.

Safety Precautions While Charging an RV Battery with a Generator:

  • Inspect all the cords you are going to use and make sure none of them are faulty or damaged to prevent electrocution.
  • Though most people don't wear gloves while cleaning battery terminals, I advise you to do so.
  • Start the generator at least 10 to 15 ft. away from the RV windows to prevent carbon monoxide poisoning.
  • Keep the battery and generator away from flammable material. Most people don't pay any attention to the red and black on the battery. I have also made that mistake countless times. Keep that in mind.
  1. Why the Generator Is Not Charging my RV Battery?
  2. Make sure that the battery charger is working and is not faulty.
  3. Most of the time cheap battery charger doesn't work as they should.
  4. Rusty or corroded terminals of the battery don't transfer properly.
  5. Clean with wet baking soda and an old brush.
  6. Due to heavy loads or internal faults, the breaker of the generator tends to trip. Reset it if it is down.
  7. Before charging, test the battery with the multimeter to check if the battery can hold the charge or not.

How Long Does It Take for a Generator To Charge an RV Battery?

The time an RV battery takes to fully charge depends on the size of the battery, and the amount of input power. A 10-amp charger will take ages to trickle charge the battery compared to a 50-amp charger.

If you have a 200Ah battery, getting an inverter that features a 15 to 20A charging current can take 10 to 12 hours to fully charge a dead battery. If you have a 100Ah battery and the generator's unregulated output voltage is 13.6, it will take around 6 to 7 hours to half charge them battery which is enough. Otherwise, charging progressively reduces from half point so it can take up to 24 hours. It all boils down to the battery charger. A larger charger will take less time.

Why is My RV Battery Draining Rapidly?

Batteries with less shelf life tend to lose their charger from non-use. If your RV is sitting idle for a long time, your battery might lose its charge.

Check the fluid levels. Low fluid levels also drain the battery faster than normal. Make sure the terminals are also clean. Corroded terminals resist the proper charge flow.

Will a 2000-Watt Portable Inverter Generator Charge RV Batteries?

A 2000-watt inverter generator produces more than enough voltage to voltage to a conventional 10-amp battery charger, or even a triple stage charger.

Do Cement Floors Ruin Rv Batteries?

Cement or concrete floors actually don't do anything to your rv's battery; however, they do have some negative effects on the longevity of your rv's battery. This is because many cars today are built using sealed batteries instead of flooded batteries. Sealed batteries are less likely to leak and corrode over time due to their tight seal. A sealed battery can last between 5-10 years before needing replacement. Flooded batteries, on the other hand, are not sealed at all, and tend to leak and corrode much faster than sealed batteries. The longer a flooded battery sits untouched, the worse it gets. If your rv had a flooded battery (which was popular back in the 70's), then replacing it would cost upwards of $200-$300. Nowadays, most people choose to switch to sealed batteries. While the price may seem high, the long term cost savings of paying for a flooded battery versus a sealed battery is the difference between spending hundreds of dollars or thousands of dollars.


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I hope this aricle was helful in explaining how to charge your rv battery with a generator. If you have any comments or suggestions, please feel free to contact us through our contact form. Thank you for stopping by.

About Author:

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Hi, I'm Kevin Pommells, a lover of camping and the great outdoors as everyone says nowadays. I'm also a passionate soccer fan and the proud owner of, a website dedicated to helping campers and outdoor enthusiasts make the most of their adventures. With years of experience exploring the wilderness and a deep love for the sport of soccer, I'm always looking for new ways to combine my two passions and share my knowledge with others. Follow me for tips, tricks, and insights on all things camping and outdoor recreation.

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