mppt vs pwm
Hi, A nice little video comparing mppt vs pwm with the batteries in bulk mode. mppt vs pwm
Forum Discussion
RE; Panel Wiring and MPPT:
Correct me if I'm wrong,
It has been said, when using an MPPT controller, once Vabs Setpoint is reached, the controller operates in pwm mode only. If so, there would be a distinct disadvantage to using 12v panels in series with an MPPT controller.
Assuming ideal conditions, and using two 140w panels with specs of 7.9a Imp, 17.7v Vmp, and 8.2 Isc, and using a Vabs Setpoint of 14.8v:
If wired in parallel:
While in mppt mode, bulk charging at an average of say 14v (13.2-14.8), average current would be 20a (280w/14v).
Just before switching to pwm mode, bulk charging current would be at 18.9a (280w/14.8v).
As it switches into pwm mode, current would drop to 16.4a (2x Isc), and amps would taper from there.
If wired in series:
While in mppt mode, bulk charging at an average of say 14v, average current would be 20a (280w / 14v)... Same as with parallel wiring.
Just before switching to pwm mode, bulk charging current would be at 18.9a (280w/14.8v)... Same as with parallel wiring.
However, as it switches into pwm mode, current would drop to only 8.2a (1x Isc), and amps would taper from there. So if abs charging continued for any significant length of time, there would be significant losses.
Correct me if I'm wrong,
It has been said, when using an MPPT controller, once Vabs Setpoint is reached, the controller operates in pwm mode only. If so, there would be a distinct disadvantage to using 12v panels in series with an MPPT controller.
Assuming ideal conditions, and using two 140w panels with specs of 7.9a Imp, 17.7v Vmp, and 8.2 Isc, and using a Vabs Setpoint of 14.8v:
If wired in parallel:
While in mppt mode, bulk charging at an average of say 14v (13.2-14.8), average current would be 20a (280w/14v).
Just before switching to pwm mode, bulk charging current would be at 18.9a (280w/14.8v).
As it switches into pwm mode, current would drop to 16.4a (2x Isc), and amps would taper from there.
If wired in series:
While in mppt mode, bulk charging at an average of say 14v, average current would be 20a (280w / 14v)... Same as with parallel wiring.
Just before switching to pwm mode, bulk charging current would be at 18.9a (280w/14.8v)... Same as with parallel wiring.
However, as it switches into pwm mode, current would drop to only 8.2a (1x Isc), and amps would taper from there. So if abs charging continued for any significant length of time, there would be significant losses.
