We recommend for our minivan conversion, a generator no larger than 2000 watts. Smaller generators might work, depending on the actual load you plan to put on it, but I recommend one that will handle a 15 amp load at 120 volts (15 x 120 = 1800 watts). If you plan on running that load constantly, then a slightly larger one, like a 2500 watt or 3000 watt would probably be better. You should always allow a margin of at least 25% extra, just to keep from over-working the generator and causing it to overheat.
For our minivan camper conversion we recommend a propane powered generator. You have to keep in mind the amount of storage room you will have. Besides the generator, you also have to carry fuel for it. Chances are, you are going to have propane for other things, like a barbeque grill. If you have to carry gasoline, too, that’s just one extra container. Besides, gasoline is stinky and you’ll be smelling it in your vehicle for the next month! Also, having a gasoline container in the car can be deadly if you ever get into an accident!
As an added advantage to using a propane generator, the engine will last longer because they burn cleaner without all that sludge from petroleum-based fuel. The tanks are also better built, and aren’t as likely to leak or become damaged as a gas can.
Also, check reviews and sound ratings of a generator before you buy one. Many of them can be very noisy. It is always better to get one that has a sound rating that is very quiet.
Solar Panels and controls suitable for your minivan:
(For inverters, please see the Electrical Control & Distribution page.)
When choosing a solar panel for your minivan camper project, the best bet is to talk with a solar specialist. He can ask questions about how you plan to use it, how you plan to use your camper, and can calculate what you will need. But logically speaking (and using Ohm’s law) if it generates 12 volts, and you don’t want to exceed 15 amps (assuming you are going to plug it into the cigarette lighter socket to charge the vehicle) 12 volts x 15 amps = 180 watts. I have heard some say that you can go up to 220 watts, but that’s only if you can verify that your lighter socket is fused at 20 amps rather than 15. You can verify that by checking the cigar lighter fuse in your fuse compartment on your vehicle.
For our purposes we don’t really “need” to go over 15 amps, and we know that will work with ANY vehicle, so we’re staying to the low side of the equation. Also, you ALWAYS want to use a regulator with a solar panel, as they can actually put out much more than 12 volts in bright sunlight. Their output varies with the intensity of the light that is shining on them. The regulator will keep that under control so that you don’t overload something.
Also, for our concept, if you did use a solar panel it all , it is assumed it would be portable, probably in a frame to keep it from being damaged, and you would simply set it on the ground when using it and plug it into the cigarette lighter on your vehicle.
The way you use your minivan camper will also make a difference in whether you even need a solar panel or not. Solar panels come in handy if you are going to be out boon-docking for awhile and have no other power available. In that case, you want to put back into the battery (in daylight hours) on a daily basis whatever you take out of the battery in 24 hours. If you don’t, then eventually you will deplete the battery.
But on a minivan camper, if you normally use places that have shore power available when you park at night, you probably don’t even need a solar panel. Larger RV’s with tow vehicles can be parked months at a time, because they use their smaller vehicle for running around, but you will probably be using your minivan camper every day! So every time you drive it, you will be recharging your batteries!
Another thing to think about, our minivan conversion process was created with the idea that you make no holes or mount anything permanently to the minivan. So unless you are going to secure the solar panel to your roof rack, and drive around with it all day with a wire run through the window (which is pointless as long as your engine is running) the only time you would have to charge anything is after you stop at your campsite late in the afternoon! For that little bit of charging time before dark, it isn’t really worth having one! It may ONLY be worthwhile if you are parked for days at a time without other power.
So in other words, solar is not for everyone. And for the size of the solar panel that you would have to have, trying to find a place to store it could be a problem. My suggestion is, unless you do a lot of boondocking, don’t mess with it.