How To Charge RV Battery With Generator

If you are an avid traveler and camper, your RV must be your handy companion on the road. Most RVs operate on 12-volt battery systems. Although many campsites consist of power sources, a high-quality RV battery is crucial for ensuring a smooth, stress-free trip.

RV batteries are extremely popular and utilize the same lead acid technology found in cars and trucks. They ensure you a comfortable camping experience by assisting you with light when it is dark, powering the heater when it’s cold, or the air conditioner when it’s warm. They help you save gas and money as you can power your electronics in the RV without starting the vehicle. RVs also act as a source of electricity for smaller vehicles like boats, electric scooters, and bikes.

These batteries require to be maintained and kept charged above 50% for sustainable usage. One of the most popular ways to charge an RV battery is through a generator. Let’s find out in detail about the different methods for powering your RV battery using a generator.

Can Your Onboard Generator Charge Your Rv Battery?

In general, generators are not essentially designed for charging the 12-volt battery system of an RV. Although the generator’s 8 amp power can charge your battery, its slow amperage output makes the process much longer. It can also be taxing for the generator if there are appliances running while the battery is getting charged.

The ideal way to charge your batteries is through a smart charger that is connected to the electricity of the entire unit or shore power.

If a 12-volt battery is on low charge and the generator has to function for a few hours, try using a smart charger. Besides, several generators are equipped with outlets that allow you to plug the charger. This helps you to utilize the excess power produced for your benefit.

How To Charge RV Battery With Generator

Charging your RV battery with a generator is a pretty straightforward process. There are two ways you can go about it. The first method is by directly plugging your RV into the generator. This is a relatively easier but slower process. The second method is using a battery charger to connect your batteries to the generator. This incorporates a few complex steps but gets the work done faster.

Plugging Your RV Directly Into The Generator

This procedure involves powering a complete electrical system of your RV or camper.

You need to specifically take into account that your generator has to be compatible with the power systems of your RV.

In most cases, RVs with 15A and 30A plugs function with any generator that produces an output power of 120V. You will require a heavier generator if your RV has a 50A plug.

Here are the steps you need to follow to ensure that your battery’s charging safely and accurately.

Step 1

Make sure the charging capacity of the setup is maximized. The ideal way to do this is by unplugging all the electronics like the AC and fans in the power system.

This will direct all the energy from the generator towards the charging of the battery. Although you cannot unplug appliances like the fridge for a long time, it is important to understand that every added electronic item will hamper the charging speed.Step 2

Conduct a thorough check of the shore power plug of your RV. If it’s the commonly used 15A plug that is standardized in all our homes, you can move on to the next step. However, you will require an adapter if your plug is 30A.

Your generator model will tell you whether it comprises these power outlets or not.

Step 3

In this final step, you first fill your generator’s gasoline or fuel tank and then start the power. Remember to let the generator run by itself for around 3-5 minutes before you attach the RV batteries to it.

As soon as the batteries are plugged in, your generator will begin pumping power. It is difficult to estimate the exact time required for this process as the time taken is highly influenced by the generator and RV models. As this method is more time-consuming, it also eats up more fuel.

Charging Your RV Batteries Through a Portable Battery Charger

This is a promising and fast method to induce power in your RV batteries. It is a complex process as it requires the portable generator to be plugged with a three-stage portable battery charger.

These chargers are compatible and help modify and decrease the power, thus helping avoid the battery getting overcharged while boosting the charging task. It also works to be economical and eco-friendly as it saves fuel and curbs pollution levels.

Here are the steps to follow to charge your RV batteries quickly and successfully through this method.

Step 1

The first step is similar to the one in the previous method. Flip your RV battery switch to disconnect it from the electrical setup. This will ensure that when the generator is turned on, all the power is sent only to the batteries.

Check the owner manual of the battery if you have trouble locating the battery disconnect switch. If such a switch does not exist in your battery model, make sure you find a way to unplug it from the electrical system before connecting the charger.

Step 2

Find your RV’s house batteries. Use the owner manual as it can be unique for each vehicle. After you locate them, conduct an inspection to spot any areas of corrosion or disruptions.

Step 3

Once you’ve inspected the house batteries, fill your generator’s gasoline or any other fuel tank. Switch on the power and let it function by itself for a similar time frame of 3-5 minutes.

Step 4

You are two steps away from finishing this task. Now, connect your battery charger to your portable generator. After you plug it in, make sure that it is working efficiently by checking the status lights.

Step 5

If you are charging an entire battery set to reach its maximum limit, use your owner’s manual. It will provide you with accurate instructions as the setups differ from model to model.

However, if you are charging your RV batteries one at a time, here is what you need to do:

1. Detach both the cables from each battery, first negative and then positive cable.

2. You have to take extreme precautions that the metals on the terminals do not come in contact with other metals. It can be very dangerous if it happens.

3. Next, attach the negative terminal of the battery to the black negative cable of the charger.

4. Repeat the same process where you attach the positive terminal of the battery to the red positive cable of the battery charger.

5. Once one battery is completely charged, move on to the next one.

Essential Safety Steps

Charging your 12 volt RV battery with the help of a generator can seem like a complicated process. Here are some guidelines you can adopt to ensure your safety.

1. Before you put your hands on your batteries, ensure that you are equipped with insulated tools and gloves for safety.

2. It can be extremely dangerous if a metal or cable passes between the battery’s two terminals.

3. Never allow contact between the positive cables from your battery and any metal. They have the potential to release electricity if they are still connected with the battery. This can cause grave injury or damage.

4. Carry out a detailed inspection for bulges, cracks, or damages in your battery before charging it. Get rid of ruined batteries and replace them with functional ones.

5. Lastly, your battery charging process must always be conducted in areas with sufficient ventilation.

Can You Charge RV Batteries With Shore Power?

A very commonly used boating term, shore power is any source of power that is not part of the RV’s power system and is not portable. It is an advanced power charging method. When you plug your RV battery system into shore power, the battery is charged through a converter.

This device converts AC power into DC power, allowing the batteries to charge efficiently. This process can last from four to six hours. The charging is highly impacted by factors like the size of the inverter, the condition of the RV battery, etc.

Charging With Jumper Cables

Jumper cables are another alternative to charge your generator. This, however, is not the best idea and must be used only in cases of emergency. These cables make use of a second battery, usually from another vehicle to provide the drained or dead battery some extra power.

This method is commonly employed by rustic tent campers. They supply power through a functional battery of a separate vehicle to recharge their boat’s 12-volt trolling motor batteries. This process is similar to jump-starting a car. Use jumper cables to connect the black terminal to the other black terminal and the red terminal to the corresponding red terminal and start the engine. That’s it, the battery will start charging.

Charging With Solar Panels

Many travelers opt for alternative renewable methods in the form of wind turbines or solar power. The solar power system consists of a solar panel that is connected to an amp controller. This is powered in connection to the RV battery. The charge controller or the amp controller prevents the battery from getting overcharged. You can either choose a PWM (pulse width modulation ) charge controller or MPPT (maximum power point tracking ) charge controller.

Although the charging speed is extremely slow, the solar panel is an environmentally friendly option. An additional problem with charging your batteries with solar panels is that the weather is highly influential in this process.

In many cases, RVs use a combined setup of generators and solar panels to help accelerate the charging.

Charging With A Wind Generator

Similar to the workings of a solar panel, this method consists of a small wind turbine that spins to generate charge. It works on a simple mechanism. The faster the wind blows, the faster the turbine moves. Hence, the greater the speed of the turbines, the higher the amount of power generated.

Many of these turbines are capable of handling a strong breeze or a rare gust storm. Based on the speed of the wind, they are also known to produce more output than a solar panel.


The procedures in this guide and the rules and regulations enlisted in the owner’s manual of your device can simplify the charging process to a great extent. Remember that every RV model, generator device, charger, and battery is different.

You have to strike compatibility between them to execute successful and safe charging.

Make sure you put in the effort to maintain your RV batteries so that they are efficient and last longer.

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