Solar Charge Controller

steveh27 wrote:
I discovered why my multimeter wouldn't show the Short Circuit Current (SCC). The 20 amp fuse was bad. I did check behind both panel's black boxes & the connections are good. One registered Open Current Voltage (OCV) of 21.2 the other 20.8. It's rated at 21.8. The rated SCC is 7.2 amps with max output of 6.67 amp.

Results:

SCC from controller connection = 6.5
from 25' 18 ga = 6.7
from 22' 10 ga = 6.6

I need to make the final solder & heat shrink connections on the 10 ga. wire. I may shorten it a bit to 16-18' if that needs done & would help.

Now my battery has a SOC of 87% with 12.7 v and a draw of -0.2a. When connected with the various cords my Trimetric shows:
with 25' 18 ga = 13.1 v and +2.9a
with 22' 10 ga = 13.2 v and +3.0a the v went up a bit the longer connected
with 16' 18 ga wire clamped direct to battery = 13.3v and 3.0a.

Maybe all is well & I just do not drain the battery enough to allow all the amps to charge?

You can test for that by running some loads on the battery like a few lamps and fans. No solar. Note the draw on the Trimetric, say it is -15a.

Now turn on solar. Amps will rise by the amount of solar you are getting. If they rise by 7a to -8a, then you know it was just the battery acceptance rate at 3a. If it rises by 3a then you are on half array.