All the information on the internet about how to set up an RV power supply for your motorhome or van can leave you feeling overwhelmed.
There are many different ways your electrical system can be set up and so many different components, brands, and recommendations. I found it helpful to look at what other people were using in their campers and I was then able to get an idea of what I might need. The perfect RV power supply set up for your camper will come down to the needs of each individual. What do you intend to power? How often will you be away in your camper, or are you living in it full time? How much money do you want to spend on it all?
A Small RV Power Supply Set Up
I had decided I wouldn’t need much in the way of solar panels and batteries and would have very little power usage. My RV power supply would be for a little portable chiller, a few lights and charge my phone and laptop. I purchased two 12 volt 100 amp hour batteries and a 150 watt solar panel with a PWM charge controller. Very basic.
RV Power Supply Needs Grow…
Over time my RV power supply needs grew. I added another battery and solar panel. It’s not recommended to mix new batteries with old batteries or different types of batteries. So I now had two solar systems set up. This wasn’t the ideal way to set up an RV power supply but it worked for now.
And then I went even bigger. I had moved in and was living in my motorhome full time. I now have every thing I could want in the motorhome and as such my power needs had grown.
The motorhome now has three different electrical systems with solar panels and batteries for each. Check out more about how to choose batteries for your electrical set up here.
System One
2 x 12volt 100Amp/hr batteries for a total of 200 Amp/hrs.
2 x 150W solar panels
1 x 30A PWM charge controller
I use this for the lights, diesel heater, and an 1100W pure sign wave inverter. This powers any 240V mains appliances such as laptop and monitor.
System Two
1 x 100amp/hr AGM battery
1 x 90 watt solar panel
1 x 10A EPever solar charge controller
This is powering the car stereo and 12V cigarette lighter sockets for USB charging of devices, and items like the gas hot water heater and gas oven get their spark from it.
System Three
2 x 100 amp/hr Lithium batteries. 100Amp hours @ 24V
2 x 370W solar panels
1 x 40A EPever solar charge controller
These power the water pump and Samsung Digital Inverter fridge
This isn’t the most cost effective way to put an RV power supply system together for your motorhome. I wouldn’t recommend it, but sometimes this is simply what happens. Over time you realize you really want to run more electrical items on your travels. If you’re wondering how many solar panels you really need, check out this article here. Most of my electrical components were bought from Sunny Tech Solar.
EPEVER Solar Station Monitor
I use the EPEVER Solar Station Monitor software on my laptop. It’s a great way to adjust charging settings and to monitor your solar input and loads. It’ll run on old laptops, or at least it runs OK on my old Windows 7 laptop.
You’ll need to buy a special cable that connects from the EPEVER charge controller to your USB port on your laptop. It’s called an EPEVER PC Communication Cable CC-USB-RS485-150U.
The image below is a snapshot of my system at this time… Blue line = power I’m using, Red line is the power from the sun, Green line is what’s going into the battery. This is 200amp hour lithium battery at 24Volts and 780W of solar. It’s a 24V system.
It shows a time period between about 2.15pm and 2.45pm in this picture. The load (blue line) starts out at just over 2amps. That’s my laptop I’m using which is also charging. The load (blue line) increases to just under 4 amps which is where I plugged my mobile phone in to charge. The next increase which takes the load to almost 5 amps is where the Samsung 255L fridge cycles on. The big spike up to 8 amps briefly is the water pump – tap being used.
The red line is what I’m getting from the solar panels. The batteries are pretty much full, and on a float charge so the green line – what’s going into the batteries is maintained by the charge controller at pretty much zero.
One downside of the EPEVER system is that you don’t really know what your solar panels are putting out in the way of amps UNLESS your batteries are way down and soaking up the sun power. In contrast, I have an old PWM controller on which the display shows exactly what you’re getting from the sun – perhaps 12amps, and the next screen shows 2 amps actually going into the batteries. (or similar figures)
See more about my charge controllers and the EPEVER Solar Station Monitor here.
Pros and Cons of Three RV Power Supply Systems
I like having each separate system though. It gives redundancy, meaning if something breaks in one of them I still have power. Eventually I’ll reduce it from three systems down to two. I definitely recommend using Lithium batteries. The motorhome is well equipped for electrical needs. I don’t ever find myself running low on battery power or having to conserve power usage. I’m able to do all the normal things, I charge two cell phones daily and run a laptop and monitor all day every day. I’ll put the stereo on and use all the lights at night. It’s like living in a little apartment on wheels and the power is provided by the energy from the sun. With the combination of batteries and solar panels on the roof of the motorhome, I never have to worry about how much power I’m using. Even in the winter after a few cloudy days, I still have enough in the batteries. The solar panels will generate enough power even on cloudy days to keep the batteries from getting too low.
RV Power Supply Set Up for My Van
My van is a much simpler set up.
I have one 270watt solar panel, 200amp hours of Lithium battery at 12V, a 40 Amp EPever solar charge controller, and an 1100watt pure sign wave inverter. I run a little Waeco 40 litre fridge, and charge the laptop and mobile phone all using the inverter. Lights are 12V LED strip lights. I have a diesel heater for the winter, and these draw high amps on start up for a short time.