partial charges, SoC drift, and further thoughts on shade
harvest patterns vs shade
Normally my peak harvest from the van-mounted array would come at local solar noon. At this place/date solar noon is 1302 (1:02p).
But since I am (intentionally) in shade at “noon” and thereafter my actual peak is during a brief window when the whole array can see the sun:
- 0951 - 555w
- 1302 - 51w (!)
overpaneling
This is where overpaneling the bank pays off; MoAr PaNnul in challenging conditions means more harvest. Overpaneling is mainly a space problem rather than a cost problem, since higher voltage panels are dirt cheap on the used market.
measuring State of Charge
Once again I’m seeing the coulomb-counting monitors becoming unreliable under odd charging conditions. I think it is due to:
- low charge currents, dipping below the minimums the shunts need to count accurately
- failure to reliably hit Vabs where the shunts reset to 100% SoC. Normally the reset would counteract drift.
Update: later today it broke the streak and finished absorption. The shunts agree again.