I replaced a Renogy PWM charger with a SmartSolar MPPT 100|20 charger and in full sunlight, the old PWM charger was charging at the same voltage (13.5V) but almost 2 amps more current (I have 3 PVs (two 100w and one 160W) with open voltage around 20v and a single 105AH 12v LiFePo battery).
The PWM was at 100% (PV voltage same as battery) while the MPPT determined a PV of 15.3V was best. I noticed in the morning, the MPPT ramps the PV voltage between 15.3 and 18V (to determine the best PV operating point?). Is the 15.3v floor (~1.8v greater than the battery) the lowest that the MPPT can work into the 13.5 battery voltage, and that the PWM works better as the PV's best operating voltage is below 15.3? If so, then would connecting the PVs in Series help?