It probably won’t be long before the bulk of lawn mowers and even snow blowers rely on batteries in place of gas engines. And while lithium-ion batteries are an impressive feat of engineering, they’re ...

D1 is the voltage reference zener. Tied to this is a string of divider resistors (R2-6) that set the various fixed voltage levels. R7 & 8 form a voltage divider to that divides the battery voltage by ...