I just started charging up four new TB48 batteries on the SPC4500 SmartCharger. I just put the batteries in without powering them on, and they all started normal charging LED patterns ("walking" green pattern with red LED on). After a while, one of them stopped normal charging, the red LED went out, and the "top" (the 100%) green LED started flashing the letter S in Morse (dit-dit-dit, pause....dit-dit-dit, pause....). I tried removing it from the charger and reinserting it. Same thing. With the battery removed from the charger, just briefly pressing the red LED, shown lower green on solid, next one up flashing. Reinserted it into the charger, same thing. So I powered the battery on and *then* inserted it into the charger. It's now charging ok. I've not finished searching for the meaning, but does anyone happen to know what the top green LED flashing like that means? (I suspect it means "there has been an error--see if you can guess what's wrong!" ) Andy.