by daveesl77 » Sat Oct 14, 2017 5:13 pm
Back from our last long camping trip of the season and realized some stuff I should have already known.
We have 150 watts of solar in 2 commercial panels (100 watt and a 50 watt). Plus I built a crappy looking, but usable 40 watt panel that we did not take with us.
I originally installed a cheap, $15 PWM controller and now after 2 weeks of off-grid national forest camping I understand the need for a good MPPT controller over the PWM.
Granted, we were in the trees, everywhere and very little direct sun shine, but the 2 main panels were still putting out a reasonable amount of voltage and current. Problem was the controller, I never bothered to look at the operational characteristics of PWM vs MPPT. With the PWM I might as well had just the 50 watt panel. It put out power, but very little. I found myself needing to run my new Predator 2k inverter generator a fair amount to keep the battery up to snuff. I was running the dorm fridge non-stop for 16 straight days on either battery-inverter or generator. It worked great, but the solar setup which should have done great couldn't handle it.
Only time I'd really tested my setup in the past was in my driveway, with direct Florida sun, so the PWM had no problem keeping the battery up to snuff. I've now bought an MPPT and changing out the controller. Next, I had built a 20' cable to link up to the panels. In the forests I realized I should have at least double that to be able to find a possible good spot for the sun. So, I'll pull out some of my old #8 big wire that I got from an RV salvage yard and make a nice, heavy duty cable.
I made a frame to mount the panels to the roof of the camper when traveling and it worked fine, but I'm going to do some modifications to it, to make it better. Conch Fritter is going to get a major rework this winter, so lots of fun stuff to come.
After 2 weeks of dry camping, I can say with confidence that our little camper is fantastic. Often nighttime temps in the mid to low 30s, I was needing to run one of the computer exhaust fans and open 2 windows to keep from getting too hot inside. The Haier dorm fridge, just worked fantastic. The new Predator generator is amazing. Many people would come by and ask if we had a generator running. I would ask if it was bothering them and they all said "no, just can't believe it is so quiet" And it was.
dave