Along with PWM, there is one other methodof solar charge regulation that is considered the most efficient method: MPPT(Maximum Power Point Tracking).
MPPT solar controllers are the mostefficient and powerful controllers that we offer, but they should only be usedwhen the solar panel voltage is much higher than the battery voltage. An MPPTsystem is able to lower the voltage of a panel (or an array of solar panels)that is up to ten times higher than the voltage of a battery to match thevoltage of the battery without losing any of the current in the process. TheMPPT controller works at a higher efficiency rate than the PWM controller;while a PWM controller operates at an efficiency level of 75%-80%, an MPPT controlleroperates at an efficiency rating of 92-95%.
MPPT controllers also boost the amount ofcurrent going to the battery, which can vary in amount depending on theweather, the temperature, the battery state of charge, and other factors. Therewould be no negative repercussions from using a MPPT controller on a solarpanel with a voltage close to the battery voltage, but the benefits from MPPTin this sort of system would be much lower.