PWM and voltage

from this thread:

PWM just wastes any voltage higher than say 19-21V.

I think it’s worse than that.  With PWM, the panel voltage is tied to battery voltage so it wastes anything higher than one’s highest battery voltage (usually Vabs).

Knock-on effects:

  • underperforms in Bulk (12.2v is a long way from Vmp)

  • performs better with lower-Vmp panels like poly and thin-film, rather than mono

  • power output increases when Vabs and Vfloat setpoints are set higher ;  they are sneaking up on Vm

  • systems with PWM-charged banks will do better when the banks are cycled less deeply.  Not [just] because there is less charging to do but because bank voltage will be higher –> panel voltage will be higher –> closer to Vmp –> more powah!