How To Charge Trailer Battery – Multiple Methods

Charging a trailer or campervan batter example with solar

These Charging Methods Are Practical And Easy To Implement. Dead batteries of any kind are a complete inconvenience, but letting your trailer or RV batteries drop too low or even die can affect its ability to hold charge in the future. Maintaining the health of your batteries is crucial and keeping them charged is one way to help.

But how do you charge trailer and RV batteries?

Charging the battery of your travel trailer can be done with more than one method. The most common charging method is by plugging the battery into 11o volt shore power at your home or at your campground. You can also charge a trailer battery with a generator, a tow vehicle, solar panels, or a stand-alone battery charger.

Plug in to 110 Volts

The most common way to charge your battery is to plug the battery into a 110-volt shore power outlet. Using your RV or trailer’s on-board battery charger, you will be able to charge your battery fully. You can also expect a low flow of trickle charge after the battery is wholly charged, which allows the battery to stay charged.

You will most likely need a trailer power cord to hook it up to the 110-volt power source.

Use a Generator

Using a generator to charge your batteries will work in a similar way as having and being shore power cord plugged.

You can charge your batteries with a propane, diesel, or gas generator. If you use your generator to run the appliances on your RV or trailer, your battery will charge simultaneously.

Charging a trailer or campervan batter example with solar

Your Vehicle’s Alternator

If you are towing your RV or trailer, you can use your vehicle’s alternator to charge your house batteries as long as your car is running. You will usually need a 7-way connection from your tow vehicle to your trailer to charge the batteries properly. This method is typically very slow, which could be a problem if you only have a short distance to travel.

Solar Power

Consider installing solar panels on your travel trailer. Using solar power is a great way to charge your house batteries and keep them charged without needing to keep your trailer or RV plugged in. To use a solar panel, you need to make sure you have the proper wattage. A typical solar panel can handle 100 to 400 watts.

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Operate your 3800-watt portable generator right out of the box on either gasoline or propane, plus the unit holds 0.6-quarts of oil (included) and has a low oil shut-off sensor.

How will I know if my tow vehicle can charge my travel trailer’s battery?

If your vehicle has a 4-pin connector, you won’t be able to charge your travel trailer. However, if you have a 7-pin connector, you will be able to charge your travel trailer battery with your tow vehicle.

There is a straightforward way to tell if your tow vehicle is charging your travel trailer battery. You can use a multimeter to check the voltage or use the battery charge gauge installed on the travel trailer.

To get as accurate of a reading as possible, check your trailer battery’s voltage before plugging it into your tow vehicle for charging. This will work as the starting voltage and will help you figure out if the battery is charging.

If your starting number is between 12 volts and 12.6 volts, your battery does not need to be charged yet. If you get a reading lower than 12 volts, your battery could use a charge.

After you get your starting voltage:

  1. Plug the trailer or RV battery into your tow vehicle using the 7-pin connector.
  2. Turn on your vehicle, then head back to the battery.
  3. Recheck the voltage, and if it is higher than the starting number, your tow vehicle is charging the battery.
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The battery pack can be recharged from the sun with a solar panel (NOT INCLUDED); can be fully charged by being plugged into the wall outlet; and it can also be charged by plugging into your car.

How long will it take to charge my trailer battery?

The time it takes to charge your battery entirely depends on how much it has been used and could rely on the trailer brands as well. If your trailer battery or RV battery has gotten to where it is completely drained, you can expect to charge the trailer overnight. If your battery hasn’t been used much, it may not take much time at all to get charged.

The charging time also depends on the amp of your on-board charger. For example, if you have a 15 amp charger and your trailer or RV batteries have a maximum capacity of 360 amps and is empty, you can expect to charge the battery for a full 24 hours to get back to full charge.

If you are charging the battery with a generator, you can expect the same rate as listed above.

If you are using solar power, the charging time will depend on the sun’s conditions. On the sunniest days, you can expect your solar panel to charge at a rate of 5-7 amps per 100 watts each hour. If you are using a 100-watt panel, it could take up to 28 hours for the panel to charge. You can expect your battery to be ultimately charged in about four days if it was empty.

Using your tow vehicle will charge at a slower rate than solar panels because a car battery also has to simultaneously run the car.

How often do I need to charge my travel trailer batteries?

It is essential to keep your trailer and RV battery charged as much as you can. This will help you make sure you aren’t charging your battery for days at a time. It is extra important to keep your battery charged during the winter because you don’t want your battery to die and your RV to lose heat.

You should also be sure to keep your trailer and RV batteries charged even when you aren’t using them. This is not only good for the health of the battery, but it also makes it easy to get up and go on a last-minute camping trip.

How do I keep my RV battery charged in the winter?

If you are not planning on camping during the winter, it is always a good idea to take your batteries off the RV and keep them somewhere warm, like inside your house. I do not recommend it to store an RV battery in your garage because the temperatures can drop too cold. If you are going to store your RV batteries in a basement, keep them off concrete floors and place them instead on a shelf, counter, or some 2x4s.

It would be best if you hooked up to battery chargers as soon as you take your batteries out for the winter. Once the batteries are fully charged, hook them up to a battery maintainer. This will allow for a maintenance charge, keeping the batteries topped off all winter.

You will also need to monitor the water levels of your batteries. If the levels get too low, fill them back up. This step is essential but often forgotten about. Keeping water levels where they should be can extend the life of your batteries.

Keeping a DC charger on hand and or a solar power system is a sure fire thing to knowing you will have ac power and electrical appliances available for those long summer nights. Make sure to keep spare or charged rv house batteries and tow vehicle’s battery just in case.


Will my RV battery charge when it is plugged in?

If you have an on-board battery charger, your RV battery will charge as long as it is plugged in. If you have a newer RV, you will probably have a charger already installed by the factory, and you can find it within your power terminal.

How do I know when I need to charge my batteries?

It is crucial to monitor the voltage that your batteries are letting off. When your battery is good to go, it will give off at least a 12-volt reading. If you get a reading that is lower than 12 volts, you will need to plug your batteries in for a charge.

How can I charge my travel trailer at home?

The best way to charge your travel trailer batteries at home is to plug them into shore power 110-volt outlet. This will allow your on-board charger to keep your batteries charged and ready to go at all times. This is the best way to keep your batteries healthy as well!

Is it bad to leave my RV plugged in at all times?

Leaving your RV plugged in all the time can be good for your trailer batteries. This not only ensures that the batteries are always good to go, but it can also keep your appliances running and in excellent condition. You will need to monitor your batteries’ water levels to make sure they stay at a proper level.

How long do travel trailer and RV batteries last?

The life of these types of batteries varies based on how often they are used and how well they are maintained. You can usually expect these batteries to last between five and seven years as long as you take care of them properly.


When it comes to charging your RV or trailer batteries, there are several ways you can do it. The most common way to charge an RV camper battery is by plugging it into a 110-volt shore power source. This is also the best way to maintain the health of your battery. Other ways to charge your battery system are using a tow vehicle, a generator, and solar power. You should make sure your batteries are charged with a reading of at least 12 volts.