mppt vs pwm
Hi, A nice little video comparing mppt vs pwm with the batteries in bulk mode. mppt vs pwm
Forum Discussion
"With mppt, other than in low light conditions, I cannot imagine battery voltage ever getting even close to panel voltage"
Me either but I continue to see & hear of folks using 17Voc PV arrays with MPPT controllers (which to me makes very little sense} high array temps/heat will/can easily drop that Voc to the battery voltage.
"So I'm wondering if this could affect maximum power tracking? In other words, can one think of solar in terms of charging with a charger?"
When using a quality MPPT controller the battery SOC should have no affect (there are exceptions) on the tracking algorithm. An example of an exception lets say the array is over sized for the controller, high end controllers use the tracking function to reduce output current (by going away from the Vmp) thus saving them selves from destruction.
Sorry I do not understand the "charging with a charger" statement. Depending on the mode the controller is operating in, which should be controlled/mandated by the battery SOC the controller will simply output the Voltage / Current it is setup for or the array can supply. Exceptions abound controller configurations vary.
"Likewise, 1100-1200 watts of solar could supply 80 amps, using mppt. So, if starting from an 85% soc, it seems the bucking feature of an mppt would not function for very long."
Assume an array voltage of 50Vdc - the buck conversion is always active otherwise the battery would see the array voltage.
Me either but I continue to see & hear of folks using 17Voc PV arrays with MPPT controllers (which to me makes very little sense} high array temps/heat will/can easily drop that Voc to the battery voltage.
"So I'm wondering if this could affect maximum power tracking? In other words, can one think of solar in terms of charging with a charger?"
When using a quality MPPT controller the battery SOC should have no affect (there are exceptions) on the tracking algorithm. An example of an exception lets say the array is over sized for the controller, high end controllers use the tracking function to reduce output current (by going away from the Vmp) thus saving them selves from destruction.
Sorry I do not understand the "charging with a charger" statement. Depending on the mode the controller is operating in, which should be controlled/mandated by the battery SOC the controller will simply output the Voltage / Current it is setup for or the array can supply. Exceptions abound controller configurations vary.
"Likewise, 1100-1200 watts of solar could supply 80 amps, using mppt. So, if starting from an 85% soc, it seems the bucking feature of an mppt would not function for very long."
Assume an array voltage of 50Vdc - the buck conversion is always active otherwise the battery would see the array voltage.
