If the battery doesn't recharge overnight, you're outta luck. It's really not a big deal with the 248 though. It has one smallish 12V SLA battery that costs $20 or so to replace. Just pop the top cover off your 248, pull the battery out and find a like replacement on the web or at your local Batteries Plus. Only requires two solder connections. Just make sure you reconnect red to the positive terminal and black to negative terminal.