How to charge RV batteries with a generator

Can you use a generator to charge your RV batteries?

The majority of campers and RV owners use some kind of 12 Volt electric systems to power lights. These batteries have an advantage in that they store more power and hold a charge for a long time as compared to regular batteries. When this battery is fully charged, it will keep all your devices running. But what happens when you need to power it up?

Others invest in an onboard inverter to change the 12 V DC into 110 that most appliances use. This raises the question of whether it’s possible to charge RV batteries with a generator. Yes, you can use the best RV generators to power your automobile home.

However, there are several factors you need to consider when charging RV batteries with a generator. These include the size of the generator, the battery’s state, and the load of the generator on the RV.

How to charge RV batteries with a generator

Use a smart charger

Generators aren’t specifically made to charge the 12 V batteries of an RV. This is why you may want to use the smart charger plugged into the electricity of your home. While the 8 Amp produced by a generator can charge a 12 V battery, it will do that slowly and may overburden the generator. The built-in generators in an RV have been designed to power the lights and appliances of the unit.

Charging RV batteries with a generator

There are several steps you should follow when charging your RV battery with a generator.

  • Charge your battery fully or connect it to the shore power outlet. If you would like to use your generator as the power source for your deep-cycle battery, you should ensure that it’s fully charged. Check oil or gas levels and fill it up. Go through the user manual if you are unable to do that. You should then plug the generator into a power outlet and ensure that it recharges fully.
  • Clean the battery. Before you can start recharging the RV battery, you will need to clean it. This is important as a damaged battery will drain for no reason. Remember to switch off the vehicle and put the emergency breaks before you start the cleaning process. Use a wrench to remove battery cables. Detach the black(negative) cable before you can remove the red(positive) cable
  • Check the battery connections to ensure that there is no corrosion happening. Check if there are any leaks, corrosions, and bulges on the generator. When you see green, yellow, or white fuzzy things, first clean them with a wet baking soda and a toothbrush.
  • Unless you are using a completely new battery, check the electrolyte levels. When you find the fluids below, you can pour some distilled water until this reaches the fill line. You should then reconnect the components of the battery before tightening the lid.
  • In case the generator is connected to the electrical system of your RV, ensure that you turn off all appliances and lights so that it charges as much as possible. Remember to consider the temperature. If there is an ambient air temperature below 40 degrees, this will limit the charge that can be held by the battery.
  • Connect the RV generator and connect it tightly to the battery. Ideally, you should charge it for 2 to 4 hours. But before you plug in the generator, be keen on your choice of a charger. If the battery if charged half charged or drained, use a three-stage charger.

Tips and warning

To ensure that you complete the whole process smoothly, there are a few things you should know.

  • Ensure that you begin by checking all connections and wires. When you see corroded or fuzzy terminals, clean them first.
  • Hydrogen gas will be produced during the charging process. This can be dangerous in a congested place. Therefore, you will want to charge your generator in a well-ventilated place
  • Wear the right protective gear. Since battery acid is caustic, ensure that you wear the right goggles and gloves
  • Avoid an open frame near the battery or generator

Connecting RV batteries into shore power

No matter how good your shore power is, it might still destroy your RV battery. However, if you will be running the RV appliances using shore power, there will be a minimal battery drain. There are motor homes that come with power inverters that enable owners to charge 12 V batteries offshore.  The downside of doing this is that it can take 4 to 6 hours depending on the inverter’s specification and size, and the battery’s state.

Can you use shore power to charge an RV battery?

Yes, you can do it. In fact, this is a good option. You will not need an RV park shore power.  You can charge the battery from any 110 electric outlets using a 12 V battery charger. The benefit of this kind of battery is that it reads the battery power level and will not overcharge it. This is unlike the cheap battery chargers that will only be dumping power into a battery. This can in the future wear down the internal parts and cause damage to the battery.

When using a smart charger, you can set it up to meet the needs of the different 12-volt battery.  Whether you are using gel batteries or lead-acid batteries, you can set them up to deliver charge accordingly. Where you got plenty of time, you can set it to charge slowly so that you can maximize the stored power.

A smart charger will keenly watch the power levels of the battery. It will throttle back, ensuring that it doesn’t overcharge and damage it. Ideally, you should plug the smart charger into the shore power and allow the battery to charge for several hours.


You can see that the process of charging an RV battery using a generator is fairly easy. The only difficult part is in refilling the electrolytes. When you follow the above guidelines, you will finish the recharging process smoothly without any risk of an accident.

error: Content is protected !!