Building a solar trailer generator is certainly a change of pace from the motorcycle world. I’m running two 200W panels that like a nominal voltage of around 17V. You throw them in series and get 34V, and plug that into a converter/charger that’s a pretty interesting bit of electronics.
Solar panels are most efficient at their preferred voltage, which depends on how much sun is hitting them, so you have a charge controller that allows the input voltage to float around whatever the panels want to put out. Then, that gets converted to a voltage that your batteries want, and most charge controllers are set up for lead-acid. The one I have is set up for 24V, so 4 6V forklift batteries work swell.
All 500lbs of them.
So here’s the math. These are something like 400ah batteries, at 6V, so I have a pack that’s 9.6kWh. If they’re charged up, they’re going to give me more than enough to charge my motorcycle’s pack, even considering the loss in the conversions, and the losses at the charger. My pack is 3.2kWh, so at 50% discharge I’m only looking for 1.6 kWh out of it. Presuming the panels sit soaking up sun all day long for most of the week, and I only need to recharge a few times on the weekend, it should work just fine.
Next phase – making up the cables.