Explorer solar and battery grid
Explorer solar and battery grid:
My Explorer has a radio and a dashcam, and I also want to keep a spare battery (to run the dashcam 24/7) as well
as a supercap bank to jump start vehicles. The challenge is how to keep the batteries separated from each other
while both benefiting from the solar power. I want the vehicle battery to get solar to keep it topped for good
winter starting. I was connecting the dashcam battery to the charge guard output via schottky so it would get
charged when the truck was on, but wouldn't power the radio. The problem this created was when the truck went
days without running (like when I was on vacation) the dashcam would flatten the battery because it wasn't
getting any solar power. But when I moved the schottky to the truck battery, then it started drawing power
from the truck battery instead and I ended up with two low batteries on long breaks because when the dashcam
battery got low it would draw power from the vehicle battery.
I tried another variation using a schottky to isolate things a bit so the backup battery and dashcam could not
discharge the truck's battery, but that ended up slowly discharging my backup battery over time because the
truck wasn't being driven enough to recharge the battery. (it was getting connected to the main battery and
solar through the charge guard) This ended up deep-discharging my backup battery, and I'm not sure just how
badly it was damaged by that. (but I'm pretty certain that its capacity was permanently reduced by a lot)
My newest design uses two solar controllers - one for the main battery and one for the spare/dashcam/supercap
box. With this arrangement, the main battery isn't connected to the dashcam so it can't possibly drain the main
battery. The supercap box and the dashcam are both connected through their solar controller's load line, which
will protect the spare battery from deep discharge. And both solar controllers will always see a battery on
their battery port. This appears to solve all three problems.
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