How To Charge RV Battery With Generator?

The RV is an amazing vehicle. It offers much opportunity for you and your loved ones to spend quality time outdoors. Especially when traveling along the countryside on the weekend, it can get you closer to nature, too. That is why it is essential to plan before embarking on a journey, and make sure that everything is checked, including a mobile home battery, for a rewarding and enjoyable adventure.

So, one of the most essential things to know if you go boondocking or camping with your mobile home or recreational vehicle is how to charge RV battery with generator. While many generators are not designed to charge an RV battery, it can be done. Typically, many would use a smart charger that is plugged into the shore power or home’s electricity. But if you still want to use a generator to do it for you, it’s fine.

An 8AMP generator can charge a 12V battery; however, it can be slow and can strain the gen set if it is also supplying AC for your appliances and devices. But then again, charging with a generator can be done.

Best Battery for RV

In this article, we’ll show you a short guide on how to charge your vehicle battery with a portable generator.

How To Charge An RV Battery With A Generator

Knowing how to do it is essential. It can maintain your battery at its optimal charged state, eventually prolonging its lifespan and preventing its damage. It can also ensure that you can supply power to your devices on-board. Check out the following steps to get started.

  • Prepare the DC charging cord

    Prepare the DC charging cord. If you don’t have one, you should buy it first.
  • rv generator user manual

    Get your generator’s user manual to read information about any specifics from the manufacturer on how to operate the generator to charge an RV battery.
  • dc outlet charging rv battery

    Find the DC outlet for charging the battery.
  • caution DC charge

    Take note not to use the DC charge function for long-term battery charging because it is unregulated. It might damage the battery permanently if left unattended.
  • plug cable DC outlet

    Plug the cable into the DC outlet.
  • connect rv battery generator

    Connect the red wire lead to the positive terminal and the black wire lead to the black terminal of the battery.
  • start generator

    Start the generator.
  • charge rv battery

    Charge the battery.
  • caution do not start generator running

    Do not start any vehicle while the generator is running with the charge cable connected to your RV battery. Otherwise, either the battery or generator will be damaged.
  • rv generator off

    Turn the generator off before disconnecting the battery charge cable.
  • disconnect clamps

    Disconnect the clamps in the reverse order – the black one first before the red one. You’re done!

Pro Tips
While it seems simple to charge the RV battery with a generator, it can turn out disastrous if you do it wrongly. See the following for some tips.

  • Don’t start with the charging if your generator is low in charge. That is why you should give it a full charge. You can also plug it into the shore power AC outlet.
  • Check the electrolyte level of your battery if you are not using a sealed battery. You should pour a small amount of distilled water on it up to the fill line. Reassemble the battery. Make sure to tighten the lid properly.
  • Check your battery connections. Are they okay without any corrosion? If you do find some whitish, yellowish or greenish buildup, clean it first. You can use an old toothbrush with baking soda to do it.
  • Is your generator wired into your mobile home’s electrical system? If yes, you must turn all the appliances and lights off. Do it to ensure that the battery will be charged fast.
  • Notice the ambient temperature. If it is below 40 degrees, it might limit the max charge of the battery. To prevent it from happening, move the battery and generator in a place with over 40 degrees.
  • Inspect all the connections and wires. Spend some time cleaning the terminals if you find any buildup on them. Pay attention to the black and red and the wire leads.

How Long To Charge RV Battery With Generator?

There is no one answer fits all for this question. It is dependent on several factors. They include the converter output, state of battery discharge and size of the battery. Many of the generator sets will charge your vehicle’s battery using a converter charger. However, it only dishes out a small amperage. It is why it can take some time to charge the battery with a generator.

At the very least, portable generators aren’t for charging RV batteries because of the limited output given by its DC, typically rated at only 8 amps. In this case, you can conclude that it takes a long time to charge your vehicle battery using this method.

Plus, the DC output’s voltage isn’t regulated or is offering constant amperage. So, as a safety precaution, never leave the battery unattended when charging with a generator. It will not stop automatically even if the battery is charged. There is a possibility of overcharging, which can give damage the battery.


The RV battery is your electrical system’s heart. It can keep the lights on and can turn the pump over when you’re taking a shower. It can also keep your appliances working. Sometimes, it is overlooked if connected to an RV park’s shore power and when the converter is dealing with the low-voltage requirements. But then, you should keep it charged so that it can continue running those stuff aboard your vehicle if you’re heading out for boondocking.

And one of the ways to keep its charge state optimal is using a generator, which typically has a 12V output. So, while it can take many hours, it is still valuable to know how to charge your battery with it. The generator can maintain your RV battery so that it’s ready in emergencies. However, make sure that you’re not overcharging the battery to prevent damage.

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