For weekend RV camping, the best way to size solar is to start with your daily power use, then build the system around that number instead of guessing by panel wattage alone. A lot of people overbuy panels and still end up disappointed because the battery bank or charge controller is too small. Others buy a huge battery and not enough solar to refill it during a short trip. The trick is to match all three parts: usage, storage, and charging.
Start by listing what you actually run in a day. For many weekend campers, that might be 2 LED lights for a few hours, phone charging, the water pump for short bursts, a furnace fan if it’s cold, and maybe a ceiling fan or a TV. If you are not using an electric fridge, air conditioner, microwave, or electric heater, your total daily use may be fairly modest. A simple weekend setup often lands somewhere around 200 to 600 watt-hours per day, depending on how much fan or furnace time you have.
Once you have that number, size the battery so it can cover at least one cloudy day, preferably more if you like camping under trees or in the shoulder season. For example, if your daily use is around 400 watt-hours, a 12-volt 100 amp-hour battery gives you roughly 1,200 watt-hours nominal, but usable capacity depends on battery type. With lead-acid, you usually want to use only about half, so that battery gives you around 600 watt-hours usable. With lithium, you can use much more of it, which makes sizing easier for short trips.
For solar panels, a common starting point for weekend use is 200 to 400 watts. Two 100-watt panels can work well for light loads and decent sun. If you want more flexibility, 300 to 400 watts gives you a better chance of recovering what you used the day before, especially if you park at an angle, get partial shade, or camp in seasons when the sun is lower. Keep in mind that a “300-watt” system rarely makes 300 watts for long. Real output is lower because of heat, angle, clouds, and controller losses.
A charge controller matters too. For a 12-volt system, a 20-amp controller is usually enough for a 200-watt setup, while 30 to 40 amps is safer for 300 to 500 watts. If you’re using a bigger array, MPPT controllers are usually worth it because they handle panel voltage more efficiently, especially in less-than-perfect light.
If you want a practical rule of thumb, many weekend RVers do fine with 200 to 300 watts of solar and a 100 amp-hour battery for light loads. If you use a fan a lot, camp in mixed weather, or want extra reserve, step up to 400 watts and 200 amp-hours of battery capacity. That gives you a lot less stress about whether the battery will be full by evening.
The biggest mistake is sizing for “what might be nice someday” instead of what you actually use now. If you want the system to work well, measure your loads, assume less-than-ideal sun, and leave yourself a little headroom. If you’d like, I can help you estimate the wattage from your actual RV appliances and build a simple setup from there.
