2 solar panels produce 0 to 20 volts. Turning serial if both lower than 11.5 volts. Turns parallel if one of them higher than 11,5 volts. To produce needed voltage for charge circuit but charger gets damaged over 25 volts. So they should not be serial at full sun. But produce enough voltage to make charger work at early hours or cloudy days.
i liked how both of them has 6 volts and output is 10 because my charger at least need 9 volts
comparing for 2.5 volts unfinished yet .
edit: added Rf to comparators. 1 source makes parallel at 11.7 and makes series at 11. the other source makes parallel at 11.6 and makes series at 10.9. hysterisis is 0.7 volts