Solar MPPT (AM-P50) The Solar MPPT is an on and off grid MPPT charge controller that will make the best of converting the solar energy to electrical energy. 500W Solar On / Off Grid MPPT Charger (UP-5P43) The 500W Solar MPPT Charger is an on / off grid MPPT charge controller that will make the best of converting the solar energy to electrical energy. 500W Solar On / Off Grid MPPT Charger (UP-5P33) The 500W Solar MPPT Charger is an on / off grid MPPT charge controller that will make the best of converting the solar energy to electrical energy. 1