San Diego California Campground Sunset

RV Solar Series: Quit wasting electricity

RV Solar Series: Quit wasting electricity. Turn it off, make it better. Measure to know where it goes. Change your location.

Turn it off

One of the things I first encountered before measuring my energy use was that I had no way to completely disconnect the battery from loads. There was a switch in the RV labeled “battery on/off”– but that was just a lie. Instead, it had a relay, that would connect the major loads from the battery to when energized to the “on” position. Where does the energy come to operate this relay, you guessed it, your battery. I installed a true disconnect switch right after I purchased the RV.

Measure to where it goes

Many small loads are connected to the battery even with the relay in the off position, thus draining the battery. With my battery switch off, I still use .9 to 1 amp per hour, this is called the parasitic draw. The parasitic draw is used to run things like the smoke detector. If I were to leave the RV without a true battery disconnect, my battery would be completely dead in 300 hours.  Many an RV owner has come back to the RV only to find the battery dead because it was never truly turned off….. the fact is that it could not ever be truly turned off. Now that we live in the RV, we never turn the battery off, because we are not gone for long periods of time and because the solar will keep the battery charged.

Last year I logged every amp our RV used every time when camping without electric hookups. Our average overnight use is 66 amps in the summer and 96 amps in the winter, including energy used during the evening but not including energy used during the daytime.  The difference is that we use the heater in the winter with a fan to circulate the heat. In the summer sometimes we use the fan in the bedroom to stay cooler at night.  Heat, when camping, comes from propane.

My measured loads (all amps per hour of operation)

  • Refrigerator alone plus the parasitic draw is 1.5 amps unless the anti-frost function is on, then more than 3 amps – no, I do not have control of the anti-frost function. (note, this is a propane absorption fridge. If you have an RV with an electric-only “residential” refrigerator my calculations won’t work for you.)
  • Furnace fan consumes electricity (4 amps), when on. The heat between sunset and bedtime winter is about 40 amps give or take.
  • LED lights (.5 per light “bulb”),
  • Inverter 4.8 amps (even if doing nothing)
  • My sleeping time electrical consumption includes a CPAP machine (4.4 amps). 

On average, when we are not in bed, we use 13 amps per hour in the summer and 18 amps per hour in the winter (assumes refrigerator, LED lights, computer, TV and in the winter heat).  When in bed, we use 6- 8 amps per hour.

If you do the math we were looking at around 250-300 per day.

Where we waste electricity is an individual thing.  Avoid using incandescent light bulbs is the number one recommendation. Our LED “bulbs” take a half a watt to operate. An incandescent bulb would take a minimum of 40 watts to produce an equal amount of light. 

Change your location

I would say we have room for improvement, but overall we are pretty frugal in the electricity department.  An obvious wintertime use that could be improved is to avoid using the furnace fan.  Still, I want and need heat, so I could use a propane heater. This is an option that avoids the fan. One thing to think about if you were going to not use your furnace, is that my furnace also keeps my pipes from freezing. The answer there is to avoid cold weather.  You could say my tires are part of my heating plan.  We also anticipate getting a better inverter and using smaller inverters with less overhead operating costs.

RV Solar Series: Quit wasting electricity

Quit wasting electricity means to use less and is the key to living with limited solar and batteries or you could make more (my plan) or plugin (noting wrong with plugging in when needed).

We created this site to help our friends with their RV questions. Feel free to ask questions or comment and we will address them to our best abilities.


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