Finding the perfect solar generator for your RV, camper, van, whatever, can either be really hard or really easy. Building one from scratch is more of an endeavor than most are ready for. Solar generators on the other hand are all-in-one units that are no more complicated than plugging a solar panel into a box with a battery and power outlets. This post will explore how to pick the right size solar generator kit that will empower your time on the road.
What’s in a solar generator kit?
The main things at work are the solar panels collecting sunlight, a solar charge controller that optimizes the energy, and a battery to store it in. A solar generator bundle includes all of these, with the solar charge controller and the battery combined in the same unit. This unit containing solar input, a battery, and power outlets is called a portable power station as a standalone product, and when combined with solar panels is called a solar generator.
What size solar generator kit should I get?
To make things simple, we’ll look at three things: Available space, how many watt-hours you can’t live without, and how many solar panels you’re willing to invest in.
What might be the starting point to work backwards from for many road warriors is how much room they can dedicate to an off-grid power solution. Watt for watt, portable power stations are more compact than 12V battery setups, so it may not be a problem for motorhomes and camper trailers that want to replace them. For vans and tear-drop trailers, how many solar panels and what size battery you need may be determined by space. Below are the dimensions for four of the best solar generators for RVs – though add a little space for airflow.
What you can't live without
Find the watts (W)
Take the electronics you can’t live without – say a laptop, Wi-Fi hotspot, lights, coffee maker, and a skillet – and add up their watts. There are lots of ballpark figures on the internet, but it’s more accurate checking the watts printed somewhere on the product. Better still is going through your normal routine and using a wattmeter so all of the power losses are accounted for. You’re in luck if you already have an EcoFlow portable power station because it shows energy input and output on its screen and app!
Find the watt hours (Wh)
Just multiply the watts of a device by how many hours you plan to use it for.
Wi-Fi Hotspot 10W
Coffee Maker 500W
While this adds up to 700 watt-hours, it doesn’t mean you’ll need a 700 watt-hour battery or that you’ll need 700 watts of solar panels, as you’ll see in the next sections.
Picking a solar battery
If you plan to use 700Wh throughout the day, you won’t need a 700Wh battery because you’ll be creating energy as you consume it. But, there are several reasons to get a battery that's biggerthan what you plan to consume in a day. One of those reasons is that it’s not ideal to use the battery from 100% to 0% all the time, and you’ll get more miles sticking to the 80% to 20% range, or 60% of the total capacity. Consuming 700Wh from the 720Wh RIVER Pro would age the battery faster than if you had the 1260Wh DELTA, not to mention that it wouldn’t offer a “rainy day fund” for days when there isn’t much sun.
Picking solar panels
Find the output watts:The rated output you see on your solar panels (e.g. 110W or 160W) is what you’d get in an ideal scenario, and in all actuality, you should be happy with getting about 70% of the number on the box. For example, linking four EcoFlow 160W solar panels (640W total) generates 2000Wh after about 4 hours in great conditions but potentially twice as long when it’s overcast. The only way to be sure is real world tests, which you can see in the table above.
To get 700Wh of solar for the devices mentioned earlier, compare it with RIVER Pro to gauge how many panels it would take to get that many watt-hours. Keep in mind that 12 hours between sunrise and sunset doesn’t equate to 12 hours of usable solar energy. People in Arizona may be able to just get by with just a single 160W solar panel, but two 110W panels would be a safer bet for most people. How much the panels generate also depends on you.
Environment: Obviously much of this is up to the whens and wheres, but make sure panels are outside, not partially shaded, and not dirty.
How often you adjust the panels: The carrying case for EcoFlow portable solar panels doubles as a stand that can be angled early/late in the day and lie flat around noon. Occasionally adjusting the panels to face the sun as it moves throughout the day will bring in more watt-hours.
Efficiency: An MPPT solar charger is now the standard replacing the less-efficient PWM. All EcoFlow solar generators use MPPT so that fluctuations in lighting and other conditions won’t throw a wrench in the works.
Let’s get your questions answered
Chances are, your shore power cable isn’t the same as a regular wall outlet – the prongs are diagonal. Even with a dog bone adapter, the amperage supplied by a solar generator might not be high enough to run bigger appliances. All of the portable power stations in EcoFlow’s DELTA series output 20A, which might slide for a 30 amp RV if you have an adapter, but not for 50 amp. DELTA Pro, our flagship portable power station, has both a 20A outlet and a 30A outlet, meaning you can power everything in your rig with solar energy.
Check out this post for more on how portable power stations can integrate with your RV.
Yes, given a couple of things: the panel’s connectors and output. Finding a cable that links your solar panels to your solar generator should be fairly easy since most panels use MC4 connectors. However, matching the solar panel’s output to the solar-powered generator’s input has nothing to do with brands. Below we’ll go into if or how many panels you can hook up.
Let’s start with: Can you even connect one? Some solar panels output too much for a small solar generator to handle. Check a solar panel’s output volts, amps, and watts and compare it with a solar generator’s solar input (different from AC input).
EcoFlow 160W Solar Panel
Open Circuit Voltage 21.4V
Short Circuit Current 9.6A
Rated Power 160W (±5W)
Input Voltage 10–65V
Input Amps 10A
If a solar panel’s output current (amps) and power (watts) are above what an EcoFlow solar generator can input, the excess will be wasted but won’t damage the unit. Excess voltage can, however, and should be within the stated range. Pretty straight forward? Well, great, because when you connect two panels in series* the voltage doubles, triples when you connect three, and so on. Amps don't change. In the above example, three 160W solar panels (21.4V × 3 = 64.2V) would be just inside DELTA's maximum input (65V); a fourth would be too much.
*Likely what you’ll be using. It means panels are connected directly to each other instead of Y-shaped adapters.
Solar is quieter and cleaner, with the only drawback being how much energy can be produced in a day. Solar can be the clear winner for those who invest in enough panels and batteries to meet their daily energy consumption.
Yes, but the problem isn’t about power, it’s about capacity. RV fridges consume around 1,000 watts a day (maybe less if it’s a small one): 5 peak hours of sunlight you’d need 200 extra watts of solar panels if your inverter and solar panels were 100% efficient. Since they’re not, two 160W solar panels could be enough to run a fridge assuming you have a battery with enough capacity to get you through the night.
EcoFlow has a solar panel suction cup kit that lets panels be attached to very smooth surfaces like the roof and side of an RV or van. Just be sure to stick a reminder on the dash!