We are offering solar charge controller. Mmpt and pwm :a mppt, maximum power point tracker or pwm pulse width modulation is an electronic dc to dc converter that optimizes the match between the solar array (pv panels), and the battery bank or utility grid. To put it simply, they convert a higher voltage dc output from solar panels (and a few wind generators) down to the lower voltage needed to charge batteries.avavlable in 4amp,6amp,12amp,24amp,30amp and 90amp.