There’s any number of reasons why you leave your RV plugged in. Maybe it’s winter and you want to make sure the pipes don’t freeze.
Whenever the RV is plugged in, the coach battery is charging. It might just be a trickle charge, but it’s a way to make sure your battery is fully charged before you head out on the road or lock up for a season. However, that little charge will deplete the electrolyte levels in the battery cells over time.
Do RV Batteries Charge When Plugged Into Shore Power?
There are two batteries in your RV that keep you energized while you’re on the road: the house batteries and the chassis battery.
The house batteries in your camper do in fact charge while your RV is plugged in. The house batteries power your 12v and 120v appliances. These include the water pump, vent fan, and interior pump.
Unlike the house batteries, your chassis battery may or may not charge when plugged into shore power. The chassis battery starts the engine and powers all the driving equipment. Most RVs charge the chassis battery when plugged in, but not all do.
It’s common for chassis batteries to not charge in smaller motorhomes while they are plugged in. In that case, the alternator charges the battery while the engine runs.
RV Electrical Systems
A motorhome’s electrical system can be a daunting thing to understand if you aren’t familiar with how similar systems work. However, the basics aren’t too complicated.
Most RV appliances run off the house battery, which is charged whenever the RV is plugged in.
That house battery provides a 12-Volt direct current (12V DC) or 120-Volt alternating current (120V AC) if you have an inverter.
12V DC Power
The RV’s house battery generates power for 12v DC appliances. As long as you have an inverter, it will also provide you with power for 120v AC appliances.
Some battery banks house 6v batteries. However, these are still wired together to generate 12 volts of electricity.
House batteries can power many of your devices regardless of whether you’re plugged into shore power or not. That being said, it is unlikely that your house batteries will be able to handle the work out of running larger appliances like the air conditioning on a daily basis without being totally drained.
This is why you want to be sure you have an alternative method for charging your house batteries while you’re on the road.
RVers traditionally bring along a generator, though solar is quickly becoming the way to bring a portable battery charger out into the boonies.
120V AC Power
120v AC power keeps all of your household appliances running. This includes the microwave, air conditioner, and power outlets.
We mentioned that running all these appliances off of battery power is a great way to run the batteries empty. A generator will keep your house batteries full so that you can enjoy the home luxuries that 120v AC power provides.
Many RVs come with an onboard generator which can help you camp in style while you’re out in the boondocks or otherwise away from shore power. You can also purchase a portable generator that stores easily onboard your rig.
How Is The RV Battery Charged On Shore Power?
With the help of a converter, AC power is converted into DC power that then charges your battery.
Most RVs have built-in converters, called a converter-charger. Larger RVs also have inverters built-in to let you convert 12v DC power to 120v AC power. This device is called an inverter-charger.
All these devices allow the house batteries to charge safely and also enable you to immediately access this power to charge your devices.
Why To Not Stay Plugged In
It can seem convenient to keep your RV plugged in. This makes it possible to keep your batteries topped off through the trickle charge. It also allows you to use your appliances without drawing power from the battery.
However, just like with phone batteries and laptop batteries, the convenience is sometimes outweighed by the cost.
Constantly charging batteries can wear on their electrolytes, lowering their overall capacity. The last thing you want while you’re out in the boonies is to find that your fully charged house batteries are only holding a charge for a fraction of the time that they should.
Another thing to consider is temperature. If your batteries are not plugged in and not in use, i.e., they are being kept in storage, then cold temperature could damage the batteries over time. Always be sure to store your batteries in a relatively warm spot to prevent any accidental temperature-related damage.
What Are Some Other Ways That I Can Charge My RV’s Batteries?
Plugging into shore power is certainly the easiest way to charge your batteries and keep them charged. However, this and your on board generator are not your only options.
Alternator. Your motorhome’s alternator might be wired so that it charges both your chassis (vehicle) and house (RV) batteries while you’re driving.
Solar. Solar power is the newer option and is now pretty common among RVers. They’re especially useful if you’re going to be spending a significant amount of time off-grid, without the option to charge at a campground or other shore power source.
Most RVs don’t come with solar power options, but there are many options out there for RVers now, and many of them are easy to install yourself.
How Do I Know If I Need To Charge My Batteries?
Some RVs come with a battery comitor that will show the batteries’ status in 25% increments, and they are compatible with single or multiple battery banks.
We hope this sheds some light on how to keep the lights on in your RV. Plugging into shore power will charge your RV’s battery. Still, there are plenty of options for charging both your house and chassis battery, no matter how far off the beaten path you roam.