how to charge rv battery while driving

How to Charge RV Battery While Driving: The Best Ways

Whether you like to go camping, fishing, or just explore nature, an RV gives you the freedom to do what you love. However, one thing that can be a bit of a challenge is to have a fully-charged battery in dry camping.

You must want a functioning and charged battery in a no-hookup campsite. We will outline some simple steps about how to charge RV battery while driving.

Do RV Batteries Charge While Driving?

Yes, they do. However, the traditional methods for automatic charging are not sufficient for fully recharging the RV house battery pack.

RV owners relied on the system of charging camper battery from tow vehicle in the past. They connected the RV’s battery pack to the alternator of the tow vehicle or motorhome through a 12V charge line. It was not the best way to charge RV battery while driving, but it was sufficient nonetheless.

But vehicle manufacturers have always been looking for ways to improve fuel mileage. So, a smart alternator has soon replaced the traditional one. While it helps with efficient fuel usage, its power is scanty for charging the RV battery pack.

Does camper battery charge when plugged into truck? You might have guessed the answer already. Yes, it does, but that won’t be enough to power up the battery.

how to charge rv battery while driving
You can charge an RV house battery while driving. Credit: CampingAXS

Which RV Battery Gets Charged While Driving?

To understand this, you have to know how many batteries or packs are working in the RV system. A travel trailer uses two types of batteries:

  • The starting or CCA battery
  • The house battery bank (a deep cycle battery)

The starting battery powers up the engine and all electronics in the vehicle. It receives continuous charge from the alternator when the engine is running.

On the other hand, the house battery supplies electricity in the RV when it’s not plugged into an outside power source. Suppose you connect the RV to the towing vehicle with a 7-way connector. In that case, the energy will mostly go to the vehicle’s electronics that the starting battery also powers up.

So, the house battery won’t get much of that power. The maximum amount could be 5 amps, which is nothing more than a trickle charge.

How to Charge RV Battery While Driving: The Best Ways

So, how to charge a trailer battery while driving? Remember that if the battery does not get charged at the time of driving, you won’t be able to do boondocking.

For how to charge RV battery while driving, you can rely on any of these solutions:

Use a DC to DC Charger

Whether your vehicle has a traditional alternator or the recent smart model, a DC to DC charger is an effective solution for keeping the house battery pack charged.

This charger improves the charging proficiency and transfers more than just trickle charge. Set it up inline between the RV’s battery and the tow vehicle’s alternator. It will monitor and ensure the correct amount of DC power transmission to the house battery.

Install an Onboard Generator

Another way for how to charge a deep cycle battery while driving is using an onboard generator. When you have a less powerful (weaker than 12V) charging setup, a generator comes in handy in recharging the battery while driving. You will need to use a 120V converter to transmit the generator’s power to the RV battery.

These days, some hybrid trucks have built-in generators, which are large enough to supply energy to multiple 120V electronics. With the help of the RV’s built-in converter, you can quickly draw power from the truck to the house battery at the time of driving. If you do dry camping often, using a hybrid truck as the tow vehicle will solve your battery power problem.

charge rv battery while driving
You can recharge the battery from an onboard generator. (Credit: OutdoorsEra)

Add an Auxiliary Alternator

If you are looking for another solution for how to charge RV battery while driving, install an extra alternator. However, the voltage drop could be a big problem in this setup.

The more the distance between the house battery pack and alternator, the more significant the voltage drop. It’s a perfect solution for motorhome owners because the house battery and alternator sit close to each other there. But the distance is too far to maintain a constant voltage supply in a towable RV.

However, you may still make this work by using heavy-duty wires and robust connectors. There are auxiliary alternator kits available that make the installation a breeze.

Install a Large Inverter

Many RV owners take advantage of large inverters’ ability to transmit electricity at high voltage. High-voltage electricity transferred through heavy-duty power lines can easily power up multiple large appliances and electronics.

A large inverter can transmit high-voltage electricity to RV’s electronics and house batteries. As a result, the battery receives enough power to fully charge while on the road.

You will need to hardwire the inverter under the tow vehicle’s hood. Combine this setup with an extra alternator to get the best result. Also, your RV should have a converter to transmit the power from the source to the house battery and other destinations. A heavy-duty connecting wire is mandatory too for electricity transmission without any voltage drop.

This system will generate 120V electricity at the source. This high-powered electricity won’t take much time to recharge the RV battery when driving. With a large inverter and auxiliary alternator, you will never have to worry about a depleted RV house battery.


How to charge RV battery while driving? By following these simple ways, you can keep the battery charged at the time of driving. This will help ensure that you always have power when you need it and stay worry-free about running out of juice while on the road.

You will also have a fully charged battery ready when camping in a remote place. Happy travels!

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