my gopher battery indicator is too optimistic, leading to over-discharging batts. how to wind it back pls? it's an all rounder, but i hope they're all similar, and adjustable. pls advise, and suggest viable setpoint for working voltage. [minus one led from right end at working voltage?] 50ah batts, nom current 10A on flat, 75A motor [max] measure work volts awkward, will take few days.