PWM controller question
I'm looking at the following panels, which are too big for indoor storage, but I think I have a viable plan for side mounting them http://2solar.ca/product/12v-140-watt-pv-solar-panel/ And I'm l...
Forum Discussion
jrnymn7 wrote:
Using a .25v drop max, and 14.8 Vbatt and 16.75 amps (2 x 8.37 Isc), I would need to go with 2ga wire for a 50' run.
The PWM controller I linked above wanted 0.25v for the short controller to battery run but was happy with 0.5v for the longer panel to controller run.
At 14.8 your amps will taper so will voltage drop.
EDIT looks like a 0.67v drop at 50 ft of #6cu and 17a at 13v. That would be fine IMO. Not going to see much diff between panel Isc and amps to the battery with that.
I get about 0.5v drop with my panel to controller run at 12 to 15 amps with no difference between panel Isc measured at the panel and the amps seen at the battery. Not sure what gauge to call the hodgepodge of jumper cables and connections in my run.
The ultimate test of your set-up is just that. Aim the panel at the sun with the panel disconnected, take the Isc, connect back up and run over to the battery monitor or solar controller display before any clouds go by and see what the amps are at the battery. Should be the same. If battery amps show lower, then you can decide if it is worth improving the wire run.
