We travel full time, and live and operate an online business from our RV travel trailer, so we’re always searching for power.
In this guide, we demonstrate how we get electricity from (1) AC electric sources, like outlets found at home, in many RV parks, and on power generators, (2) DC electric sources, like our deep cycle 12V ‘house’ battery, and (3) RV solar panels.
We are not experts; this information is based on research and experience, so we won’t be using complicated terminology, but we’ll do our best to explain everything simply and thoroughly.
Table of Contents
Chapter 1: AC Electric Power – Plugs and a Generator
Chapter 2: DC Electric Power – Batteries and an Inverter
Chapter 3: Recharging Using AC and Solar Power
Epilogue: Okay, to Summarize…
Chapter 1: AC Electric Power – Plugs and a Generator
AC, or Alternating Current, electricity is the kind most commonly associated with powering homes and businesses. For RV purposes, AC electric is used when sourcing from a house, RV park, other business, or power generator. In travels, AC is commonly referred to as ‘shore power’ and usually provides between 110 – 126 volts.*
*Testing campground power outlets with a multimeter is a good idea, especially with older campgrounds. If the wiring is substandard, the meter may read below 110V, which can be bad for your electronics. See this helpful blog for more info:
RVs accepting AC electric will have a 50 amp, 30 amp, or a 20/15 amp receptacle. Our fifth wheel travel trailer uses a 50 amp RV plug.
What’s an amp?
Amps, or ampere’s, are the base measurement for electrical current. So, a 15 amp plug can handle 15 amps of electrical current. Any more than 15 amps will usually trip a breaker switch or blow a fuse, but if not protected the plug can melt and/or start an electrical fire.
Caution: Electricity is dangerous.
Our 50 amp RV plug can handle 50 amps of appliances at the same time when plugged into a 50 amp receptacle. These types of receptacles are typically only found at RV parks, but not all parks have them.
To figure out how many amps an appliance is using, check any labeling on the device, look at the instruction manual, or search the internet for any information regarding your appliance (or one similar).
Labels are all different but will generally show electrical input and output in terms of AC or DC, Voltage (V), Watts (W), and/or Amps (A).
Here is the basic formula for calculating watts, amps, and/or volts if your label is missing one:
Volts x Amps = Watts
120V x A = 1500W (air conditioner)
So, we divide Watts by Volts to get Amps:
1500 / 120 = 12.5 Amps
In order to stay within our 50 amp limit, the amount of amps being used by our appliances must be at or below 50.
We are always on high alert if using energy hungry appliances like Air conditioning, the microwave, the electric water heater, a blow dryer, the vacuum, or a coffee maker.
If we are trying to plug into a less than 50 amp receptacle, adapters are required.
Many places do not have a 50 amp receptacle for us to use, including lots of RV parks. When this happens, we use our 50 amp to 30 amp adapter. When 30 amp isn’t available, like when we plug into a household outlet, we use the 50-to-30 adapter anda 30 amp to 15 amp adapter.
**It’s important to note that the lowest adapter number in the conversion is the amount of power available for use. Even though we have a 50 amp plug, if we are converting down to 15 amps, there will only be 15 amps of power available.
No shore power available? Start the Generator.
Our next option for AC electricity is a power generator (genny). There are many genny options, including gas, diesel, and propane powered versions of all wattage levels.
Motorhomes, and even some trailers, can come with a generator already installed, but our trailer didn’t, so we had to go with a portable version.
When it came to choosing a generator, important factors we considered were (in order of importance):
- Power needs (measured in wattage)
- Physical size/weight
- Fuel type
- Price
- Quality
Power– We wanted to be able to run the Air conditioner if we needed to, so that meant finding a generator over 2000 watts. However, some recent internet chatter has indicated that a soft start switch can be added to your setup, which helps allow A/C to run from a 2000W genny.
Physical Size/Weight – We’re always conscious about adding weight to our rig, so we didn’t want to go too large. Plus, we wanted to be able to carry it!
Fuel– We tow our travel trailer with a Ram 2500 Cummins diesel truck. Since we don’t need to carry regular gasoline, we didn’t want to start just because we got a genny. Plus, regular gas contains ethanol which will eat at the rubber components of the generator if left unattended. Diesel generators…are expensive. So, that led us in the direction of a propane powered generator. We already carry propane and it’s cheaper and cleaner burning, so it was almost a no-brainer.
Price – We live on a budget, so we’re usually looking for the cheapest, best option.
Quality – The purpose of the generator was to provide a back-up source of power, so it needed to be reliable, but we were willing to sacrifice some quality to meet other needs.
With all of these factors to consider, there weren’t many options under $1,000. So, we went with the Sportsman 4000LPG. It has:
- Power: 4000 surge watts and 3250 running watts, so plenty to power the A/C and then some
- Size: We can both carry it by ourselves, even though we generally use a hand truck
- Fuel: It runs on propane
- Price: It was cheap
- Quality: The quality is cheap, but we purchased the 3-year extended warranty for insurance.
To date- 09.2018 – our one-year old genny has logged 190 operating hours, 4 oil changes and one air filter cleaning.
It starts up every time without hesitation- it can sit for months and then fire up right when you need it.
At $350, we are definitely happy with this purchase. When we factored in the 3-year extended warranty, we could buy three of these generators over the next nine years for less money than buying a single expensive model.
If we had unlimited money, we would probably would go with an expensive, reliable name brand generator and install a propane conversion, or just buy an LP model, which is all available for around $1,500+.
Chapter 2: DC Electric Power – Batteries and an Inverter
DC, or Direct Current, is the kind of electricity most associated with batteries.
While we use regular household batteries to power remote controls, flashlights, smoke detectors, a fridge fan, and a few other things, a special battery is required to power our trailer.
A Deep Cycle battery has an extended discharge capability at a lower rate, which is what you want to power things longer term. Short term power at a higher rate is the kind of battery you might use to start a car or truck, and not one to power electronics in an RV.
We did a lot of research about batteries after ours died when we really needed it. You can read about that catastrophe in our blog We Dropped the %$&@! Trailer.
The battery that came with our used RV was a small 12V marine battery from Die Hard. It wasn’t right for the job and it died before we left our first site.
In the hunt for a more reliable battery, we realized we were going to have to spend a bit of money to get some peace of mind.
At $225, our 12V Trojan 31AGM has been a fantastically reliable battery. We chose this battery because:
- a 12V Group 31 size was the largest we could fit without using additional storage and routing new wires. Ugh.
- Trojan is a well-known brand with a loyal following.
- We wanted a sealed battery as opposed to a battery you have to maintain with water, so an AGM (Absorbent Glass Mat), or maintenance-free battery, seemed like the best option.
- It boasts a 100 amp hour rating.
There are a variety of battery configuration options, and this is by no means the best, but it works for us right now and we are happy with it.
Since this was the largest battery we could fit (in our trailer and our budget), we make due, but maybe someday we’ll be able to purchase a lithium battery- a lighter, more powerful, and longer lasting battery that comes with a hefty upfront cost.
What the battery does and how long it lasts.
The battery in our trailer acts as the power hub when we’re not plugged in to AC electric. It powers many appliances, like the electric jacks that hold our trailer up, the electric stabilizer motor, most of our lights, the water pump, the propane refrigerator, the vent fans and any other onboard 12V device.
Our battery has a 100 amp hour rating, but lead-acid batteries are only supposed to be discharged to 50% for better lifespan, so that means we have about 50 amps of power to work with before we need a recharge.
To figure out our exact usage manually, we would need to calculate every appliance’s amp rating and use a stopwatch to time how long they are using power. This is obnoxious, so we use guesstimates and conservative figures to stay within our limits. I’m sure there is some super high-tech way to monitor our electric usage, but we’re not that fancy.
As an example of power usage, 3 LED lights use approximately 1 amp- meaning that in 1 hour, 1 amp has been depleted from our battery.
Fun fact:Just 1 incandescent trailer light uses about 1.3 amps and runs hot to the touch, making LED’s much safer and more efficient!
Heavier appliances are more cause for concern, like the water pump. That hog consumes about 6 amps of power, so we try to use it conservatively when we are not on AC electric.
So, how long our battery charge lasts depends highly on how we use it, but on average we can power essentials for about 24 hours.
Using the Battery to Power 120V Appliances
Our battery also powers an inverter, which turns DC electric into AC electric. This is helpful for using items that have a 120V AC household plug, like our oscillating fan, laptop chargers, and television. Inverters also consume electricity, so we have to factor this into our power usage. Smaller inverters use around 1 amp of electricity, while larger inverters can consume several amps, just to be powered on.
Originally, we purchased a cheap 400 watt modified sine wave inverter with no fuses, but it died about 10 months in. It was replaced with an emergency, cheap 400 watt inverter (this time with a fuse) until we received our new top-of-the-line 600 watt pure sine wave inverter.
The difference between the modified sine and the pure sine has been noticeable. The fan on the pure inverter hardly ever turns on, whereas the fans on the cheapies were always running. Also, the power from pure sine is cleaner; the modified sine caused my fan to make a funny noise and caused horizontal black lines on my TV screen.
Our inverter is mounted next to the battery, as per the manufacturer recommendations. An extension cord passes through the wall (a hole we drilled) and runs up and over the inside of the pass-through compartment door, and into the trailer through the air intake vent through the stairs.
Chapter 3: Recharging on AC and Solar Power
Our battery is relatively small for the amount of strain we put on it.
50 amps of battery just isn’t that much when you’re trying to run an online business!
Once, we tried charging our laptops directly from the battery- big mistake. Each laptop drained about 15 amps, leaving us at 70% battery power without factoring normal appliance usage.
So, we found that in order to run our business we either have to, (a) be plugged in to AC electric, or (b) have the battery plugged into solar panels with reliable sunshine available.
Recharging the Battery on AC
Inside our RV, under the refrigerator and behind the fuse box, is our charger/converter. This device converts 120V AC electric into 12V DC electric for the 12V appliances like the lights, water pump, electric jacks, and others we’ve mentioned. In addition to converting 120V to 12V, it also charges the battery, hence the name charger/converter.
Side note:This is a good time to point out the difference the inverter and the converter. The inverter is used when AC power is not available; it turns 12V battery power into household 120V power. The converter is used to turn 120V electricity into 12V power. Both the inverter and converter are necessary because the RV has a mix of 12V and 120V appliances.
Recharging the Battery on RV Solar Power
We are fairly new to the solar game but are already enjoying it immensely! We decided to try free camping more while touring the western United States, so solar became a necessity for our budget. Running the generator all day, every day seemed excessive, and expensive. Plus, it’s noisy, while solar power is silent (so we’re able to hear more nature!)
How we came about our solar panels is a bit of a story, and we like to tell it in person, so if you’re interested, let’s have a campfire and some beverages!
Our solar set up consists of:
- Two 120 watt ACOPower portable solar panels (240 Watts total)
- Renogy Adventurer 30 amp Solar Charge Controller
- 8” of 10 gauge wire connecting the controller to the battery
- 30’ of 10 gauge wire connecting the controller to the 2 panels
- MC4 branch connectors, to connect the two panels in parallel*
*Connecting in parallel means we are doubling the ampere output, whereas connecting in series would double the voltage. Since I’m charging a 12V battery, and a single panel is meant to charge a 12V battery, we wanted to double the ampere output instead of doubling the voltage.
How Our Solar Setup Works
Solar panels collect solar power, but that power needs to be regulated through a charge controller. The charge controller regulates the amount of electricity flowing into a battery, from the panels.
When appliances draw power from the battery, the charge controller draws energy from the solar panels to recharge the battery. So, the battery remains the energy source for any appliances, and the panels are used as a method of recharging the battery.
Our ACOPower panels came as individual solar kits, which each included a 10 amp charge controller and alligator battery connectors. We also ended up with a Renogy 100 watt solar briefcase, which included a 30 amp charge controller.
Connecting the two 120W panels together can generate more than 10 amps in good sunshine, so we used the 30 amp controller, kept a 10 amp controller for backup, and connected the other 10 amp controller to the Renogy 100W panel.
We wound up selling the Renogy briefcase since it was only 100 watts and weighed in at a whopping 30 pounds. The other two panels equal 240 watts and total 16 pounds combined weight- a no-brainer for the weight-conscious RVer.
The 10 guage wire came as a later purchase after we realized the panels weren’t putting out as much power as they should’ve been. We added 30’ of extension wire and this length is usually enough to reach the sunshine when it’s out, but another couple of feet would be handy sometimes.
At peak charging times, we see up to 12 amps of power being pushed into the battery at well over 14 volts (the battery manufacturer’s recommended charge rate is 14.4V). If our battery is at 60% capacity (60 out of 100 amps), that means we would need 40 amps of charge to bring it up to 100%.
If the panels are pushing, say, 10 amps, it would take about 4 hours to recharge the battery.
The percentage of the battery charge can be tested with a multimeter, following this chart:
Here are just some gratuitous shots of us harvesting sweet rays:
Epilogue: Okay, to summarize…
AC electric comes from plugging the RV into a land source, or a power generator. These sources will usually provide between 110 – 126 volts, which will allow the use of the household electrical outlets in our trailer.
If the trailer is plugged into a 15 amp source, like a household outlet, we only have 15 amps of available power to use. But, if we are plugged into a campground with a 50 amp receptacle, we have 50 amps available for use. Our generator has a 30 amp RV receptacle, so we use our 50 amp to 30 amp adapter and enjoy up to 30 amps of power within the generator’s 3250 watt limit.
Real life example:
A/C (12.5 amps @ 1500 watts) + Microwave (12.5 amps @ 1500 watts) = 25 amps @ 3000 watts
DC electric comes from our 100 amp hour deep cycle ‘house’ battery, which will power 12V essential items like lights, the water pump, etc. for about 24 hours before needing to be recharged.
We can recharge the battery through the converter by plugging the RV into an AC electric source, or we can recharge the battery using our RV solar panels and charge controller.
To power 120V appliances while using battery power, we use an inverter, which turns 12V battery power (DC) into household 120V AC. Our 600 watt inverter will power our laptops, oscillating fan, 32” LCD TV, and a Nintendo Wii without breaking a sweat, but it is no match for power hog appliances like the microwave, A/C, a toaster oven, or a hair dryer.
That’s it, that’s how we power our lives in a travel trailer!
When we were newbs, it took many experiences and hours of research to learn all of this information, so if you’re new, stay calm and start bookmarking and taking notes if you haven’t already! Electricity can be complicated, and remember, it’s also dangerous, so be sure to get all the info you can, and if you don’t feel comfortable doing something, find a professional.
Have more questions, or a story about RV electricity you want to share? Leave a comment!