We don’t have our van yet, so for two weeks of camping, with some boondocking, we rented a converted minivan from Lost Campers. In order for Becky to sleep comfortably, especially at altitute, her CPAP with humidity/heat is essential. This means 300-350 Wh/day, with no other consumption. We decided to try out the Goal Zero Yeti 1000 Lithium from Costco, both for this trip and as a possible initial electrical system. My theory was that we would use it as a temporary system on our Promaster once it arrives. Since there is no DC charger yet, I figured it was a good chance to experiment with solar too.

Lost Campers van with Solar

I picked up 2x Renogy 100W panels, and the Yeti 1000 has 2 Anderson Power Pole connectors for solar input, so I built a Power Pole connector to 30’ MC4 extension cable and used Y-connectors and short cables to connect the 2 panels in parallel. Since this isn’t our van, we can’t mount panels on the roof, but portable panels means we can park in the shade and have panels in the sun. This has worked reasonably well when stopped for a full day and not surrounded by big trees. Unfortunately, that has been true for only one day out of our seven day trip so far.

Overall, we aren’t too impressed:

  • in full sun, with panels angled precisely, the PWM solar charger tops out about 135W (panels in parallel as recommended by Goal Zero)
    • Solar charging takes much of the day to charge from 40% -> 100%, even reorienting panels regularly for max input
  • 80 Ah battery is too small - enough for 2 nights CPAP and not much else, 3 nights takes below zero
  • no DC charging option (yet), since Goal Zero DC chargers are set up for their non-Lithium batteries
  • AC charger is slow, 57W input from A/C, where a larger AC/DC converter could provide up to 1800W. (OK 1800W charging is a bit excessive, even if it is only 1.8C, well within typical Lithium battery tolerances, but 57W is 3% of that)

Options to make it more usable:

  • Get a 12V aux plug inverter, and connect it to the Yeti’s AC charger - at 57W, even a small inverter should work, but that’s still a lot of driving - 6 hours to recover 350 Wh
  • permanently mount solar to the roof of the vehicle, and charge while driving
    • Yeti max input is 360W solar at max 30V, and this would make for faster charging while driving

It is nicer than the older Yeti batteries, which took a long time float charging to reach full capacity, but still not a good solution for our needs.