A typical RV battery bank of one to two dual purpose RV/Marine Deep Cycle batteries will generally last about 3/4 of a day of normal use while boondocking. This is also assuming the RV has a single 200-watt solar panel on the roof continuously feeding power back into the battery bank. How long will RV batteries last while boondocking? It really depends on a lot of factors…
How Long Will RV Batteries Last While Boondocking?
Let’s consider the “typical” RV is set up as follows…
- One (1) deep cycle RV/Marine 12 volt battery, rated at 100 amp hours (AH)
- A single 200 watt solar panel mounted to the roof
- The usual 12 volt RV amenities (ceiling vent fans, water pump, power awning, power tongue jack, lights, USB outlets, furnace, and absorption refrigerator).
Let’s also make the following assumptions…
- The RV is parked under full sunshine during the summer.
- There are two adults camping in the RV.
- Most of the afternoon hours are being spent outdoors.
Under the above scenario, that single deep cycle RV/Marine 12 volt battery, which is a standard feature on most RVs, will provide enough power from sunrise to sundown, and continue providing ample power until the couple goes to sleep.
This is mainly because the 200 watt solar panel on the roof, sitting under full summer sun, is feeding power back into the battery, AND the fact that the couple is spending most of the afternoon outside, and not consuming power inside.
What Causes the Battery to Lose Power Quickly
The reasons why most single battery RVs lose their power so quickly is largely due to excessive power consumption and poor solar panel performance…
- If the couple chose to spend the entire day inside the RV, using the lights, running the ceiling vent fans, and watching television, their battery will run out of power by the time the sun goes down. This is because their single 200 watt solar panel on the roof is not able to keep up with their power demands. Thus by the time the sun goes down, the battery is already half-dead and just about ready to call it quits for the night.
- If the solar panel is shaded by trees, it won’t be able to send much power into the battery during the day.
- Running the furnace at night will quickly drain a single RV battery in just a couple of hours. This is because the furnace has a fan that consumes a lot of power in order to push heated air through the RV’s heating ducts. Plus at night, there is no solar power to offset the power draw.
The Trick is to Have Full Batteries for the Evening
As long you have solar panels on the roof, and you’re getting full sun during the day, solar power can usually do a good job of keeping your battery topped off and ready for evening use.
Thus it’s important to spend more time outside during the day so that your panels have time to recharge the battery. If you cannot spend more time outside, then try to minimize power usage by keeping the lights off, not running the ceiling fans, and not running the water faucet.
Recommended Battery and Solar Panel Configurations for RVs
Based on how much power you consume, here are the configurations we recommend for boondocking in an RV…
- Light Power Users – single person, or two energy-conscious adults – Install two (2) 12 volt deep cycle RV/Marine batteries at 100 amp hours each. 300-400 watts of solar panels on the roof.
- Average Power Users – two adults or family of four – Install four (4) deep cycle RV/Marine batteries at 100 amp hours each, or two (2) 6 volt golf cart batteries at 220 amp hours each. 600-800 watts of solar panels on the roof.
- Heavy Power Users – two adults up to family of six – Install three (3) to four (4) 100 amp hour 12 volt lithium batteries. 800 to 1,200 watts of solar panels on the roof.
Light Power Users are defined as those who spend most of their daylight hours outside, keeping power consumption to a minimum, and allowing solar panels to keep batteries topped off for evening use. These users have an absorption refrigerator that runs on propane full time, and but will still allow the furnace to run at night on a low thermostat setting.
Average Power Users are defined as those who go in and out of their RV during the day, allowing the lights to stay off during the day, but still running the ceiling fan. The water pump is used throughout the day from the kitchen sink and toilet. One laptop or cellphone remains on a USB charger. They also utilize an absorption refrigerator running on propane all day. They also have a 2,000 watt generator to run the microwave oven and cooking appliances. They watch television at night until they go to sleep.
Heavy Power Users are defined as those who spend more time inside the RV during the day. They keep the lights on and the ceiling fan running all day. They’ve opted for a 12 volt refrigerator instead of absorption. They have a 3,600 watt generator or higher so that they can run the air conditioner. However, they installed a 3,000 watt inverter so that they can run the microwave, coffee maker, and food processor from battery. They also work on their laptops all day, keeping them plugged into the inverter. They are trying to publish a YouTube channel, so they also need to charge their cameras and drone. They need to run their furnace all night and one of the adults sleeps with a C-PAP.
The Furnace is the Biggest Battery Hog
Propane furnaces installed into RVs have a fan that pushes heated air through duct work. This fan needs a lot of amps to push air effectively. A single 12 volt, 100 amp hour battery, can be drained in just two to three hours of furnace use.
If you plan to rely on your furnace for heating through the night, you’ll need at least four (4) of those batteries, or two (2) 6 volt golf cart batteries, to provide enough power to get you through twelve hours of use. You’ll also need 600-800 watts of solar to keep those batteries topped off during the day.
Note: you cannot run the furnace during the day, then continue running it at night. Your solar panels will not be able to keep your batteries topped off during the day if you try. Thus by the time the sun goes down, your batteries will not be ready to keep that furnace going at night.
- The better solution is to use a portable propane heater such as the Mr. Heater Buddy (see it on Amazon), which can run 3-4 hours on a standard propane bottle, or about 1 week on a 5-gallon propane tank. They don’t require any electricity to run, and you can move the heater to wherever you need it.
Can You Run Air Conditioning From Batteries?
Not really. Yes, several people have configured their RVs to run air conditioning from battery power, but it requires a lot of battery power and a lot of solar panels. Even most people who have set up such systems typically can only run air conditioning for 3-6 hours total, and will then have to wait until their batteries fully recharge before continuing.
Read, “How Many Batteries Does it Take to Run an Air Conditioner?“
You’ll Need an Inverter to Power Wall-Outlets From Battery
An inverter is needed to power wall-outlets from battery. RV manufacturers do not install inverters in their budget line of RVs. It’s something only found in their high-end models.
If you want to recharge your laptops and phones, run your television, or even run your microwave oven from battery power, you’ll need an inverter. Inverters are rated in terms of watts. Get at least a 1,000 watt inverter to power a television and recharge your laptop and phones. If you want to also power your microwave oven, then you’ll need at least a 2,000 watt inverter.
Serious power users will install a 3,000 watt inverter to go along with an aggressive combination of batteries and solar panels to run a microwave oven, a television, a 12 volt refrigerator, and charge their cellphones all at the same time.
