Review on ⚡️ Battery Charge Controller with Digital Display & Protection Switch - 12V, 24V, 36V, 48V Battery by Ryan Springer

later Edit: Not DOA, it's only powered by a battery, not a charger, so you have to connect a battery for it to turn on. Only charge the charger after it has been programmed. I deducted two stars because a) the instructions suck and the above isn't mentioned, b) it draws 4 watts in standby mode (!) and c) it didn't come with a work stand. Also, you have to infer which button is which, based on the defaults set in the description, you can't read Chinese because that's the only writing on the board.