RV Electricity Explained
RV electricity is a topic that seems to leave a lot of people with questions. While an RV electrical system is not simple by any means, it’s easy to make sure you don’t have any issues as you enjoy StressLess Camping.
Essentially there are effectively two electrical systems in an RV; the 110 volt system like in your house that is fed by that big cord that attaches to the pedestal at a campground and a 12 volt system driven by the batteries. Yes, this is an oversimplification but stick with us.
The 12volt system runs your lights, the fan in your heater, the circuit boards in your refrigerator and heater, the water pump and vent fans, if you have them. There are also likely to be 12volt USB charging stations if your RV is newer. All of this basically uses battery power but also has a relatively small draw. Your carbon monoxide sniffer, too, uses battery power and emits a repeating loud chirp if it senses that battery power is low.
If you’re plugged in to “shore power” such as at an RV park via the fat cord that came with your RV then you’ve got 110vac power. In this case, there is a heating element that operates in your refrigerator and one in the water heater so you can run those appliances from shore power. You will also be able to use the 110vac outlets throughout the RV and your air conditioner(s) and microwave will work as well.
This shore power will also run through your RV’s electrical system to charge the battery(ies).
A lot of people don’t understand this shore power. In your home, for example, you might be running the air conditioner and a hair dryer and a microwave all at the same time. So why can’t you do this in some RVs?
A basic way to measure the amount of electricity coming into your RV is with amperes, or amps. Many RVs, especially those with one air conditioner, have a 30amp electrical system. Larger RVs such as motorhomes and larger fifth wheels and travel trailers likely have a 50amp system.
Compare this to most homes that have an electrical service between 100 and 200 amps and you’ll see why an RV is a much less capable system. So what is an amp and why does it matter?
Think of one amp as a puzzle piece. In a 30amp system you get 30 puzzle pieces to build your electrical “house” on.
If you look at any appliance or item that draws electricity they typically measure their consumption in watts. For example, a hair dryer might boast that it’s 1700watts of power. Again, this is a vast oversimplification, but you can think of 100watts as roughly one amp.
So, when you’re drying your hair in the morning you’re drawing about 17amps of power. With 30amps in your RV that leaves just 13amps for everything else. That means if your water heater kicks in to heat the water, it draws about 1400 watts so you’re now at maximum capacity of that 30amp circuit.
One thing to take note of is that using electricity to change the temperature of things draws a lot of power. For example, a typical LED light in an RV may only draw 1/10 of an amp but a 13,500btu air conditioner will suck down 14amps. This is why your home electric bill is more in the summer than in the winter if you heat it with something other than electricity.
You can download a chart of all the things that draw electricity in your RV and what they typically consume, but think about those puzzle pieces, how many you have and then how many you’re using at any given time.
When you run out of “puzzle pieces” but still want to add a toaster oven or coffee maker while drying your hair and running the air conditioner the universe will issue a big “no way” in the form of tripping the breaker at the pedestal outside or on the fuse box inside your RV. If you haven’t donned your clothes yet, you’re going to cause quite a stir if you have to go outside to reset that breaker!
I had written that a 50amp RV service is a different sort of animal. The 50amp service is actually two 50amp services, of sorts, and provides 100amps to an RV. This is why larger RVs use this - many of those have residential refrigerators, two air conditioners and other high-draw systems and a 50amp service can accommodate these.
As you’re planning your StressLess Camping adventure think about the various things in your RV that are going to draw power. Perhaps you might like that electric heater and toaster oven, but it might not be a bad idea to leave one of those at home. In our trailer we use propane to heat water for coffee (on the stove) using our Aeropress and do most of our cooking outside with the barbecue, having our meals planned in advance to take advantage of this.
You can still enjoy a great getaway by using the resources in your RV and taking advantage of both its propane and electrical systems. And, really, that’s why we’re getting away - is to not have to think about all this.
One more thing, at the start of this article I mentioned just two types of electrical systems but this ignores the generator, which feeds the 110vac system. You might also have a solar system on your RV but this basically feeds the 12volt infrastructure by charging the battery.
There is one more system a few RVs use - an inverter. This takes 12volt power and converts it to 110vac power. This is useful to take the stored energy in the battery(ies) of the RV and allow the 110vac outlets to work. A few RVs nowadays are coming with this or available with it as an option, and it can be added after the fact. This is particularly useful when used with solar panels to charge the battery(ies) and can be a life saver for those using things like a CPAP machine, enabling the 110volt outlets to operate throughout the night without the noise of a generator.
I also realize that people who truly understand electricity are probably pulling their hair out over this oversimplification but is to make this understandable for RVers who may have little or no knowledge of circuits and amps whatsoever. Hopefully this will help you enjoy StressLess Camping.
