mppt vs pwm
Hi, A nice little video comparing mppt vs pwm with the batteries in bulk mode. mppt vs pwm
Forum Discussion
Jim, I think the buck converter in the "MPPT" controller is always working the same way even with the MPPT not working anymore once the set Vabs is reached.
So the controller does not suddenly turn into a straight PWM that has no buck converter and can only do panel Isc. (or does it?) The real issue is what happens with panel voltage now that it is no longer being held at Vmp?
You have that mystery voltage and panel amps as the input watts to the buck converter with almost the same watts as output. Divide that by Vbatt and that's your amps now the controller is not in MPPT. As always.
I don't think that would be panel Isc unless the panel voltage were now the same as battery voltage. If it were then the buck converter would have the same voltage at each end and do nothing. So how could you get any amps? With PWM you get panel Isc at that voltage on its IV curve. If the buck converter is doing nothing does that act the same as if not even there so it just passes Isc through?
Adding a load in Float so amps go over the 24v panel's Isc shows the buck converter IS working but just not at Vmp. So what panel V is it at? Once Vbatt drops to 13.2 then the controller's MPPT kicks back in so then panel v would be back at Vmp.
Somebody with MPPT solar in Absorb or Float with just battery charging happening, please rush out right now and measure panel (or controller intake) voltage and also note what battery voltage is.
Then add a load so amps are above panel Isc. What's panel voltage now compared with Vbatt? Thanks. :)
So the controller does not suddenly turn into a straight PWM that has no buck converter and can only do panel Isc. (or does it?) The real issue is what happens with panel voltage now that it is no longer being held at Vmp?
You have that mystery voltage and panel amps as the input watts to the buck converter with almost the same watts as output. Divide that by Vbatt and that's your amps now the controller is not in MPPT. As always.
I don't think that would be panel Isc unless the panel voltage were now the same as battery voltage. If it were then the buck converter would have the same voltage at each end and do nothing. So how could you get any amps? With PWM you get panel Isc at that voltage on its IV curve. If the buck converter is doing nothing does that act the same as if not even there so it just passes Isc through?
Adding a load in Float so amps go over the 24v panel's Isc shows the buck converter IS working but just not at Vmp. So what panel V is it at? Once Vbatt drops to 13.2 then the controller's MPPT kicks back in so then panel v would be back at Vmp.
Somebody with MPPT solar in Absorb or Float with just battery charging happening, please rush out right now and measure panel (or controller intake) voltage and also note what battery voltage is.
Then add a load so amps are above panel Isc. What's panel voltage now compared with Vbatt? Thanks. :)
