I've got the Zippy K 4300 3S pack and the Imax-8 charger. I also see 4.25v per cell on a ballance charge. This is my first experience with lipo's and I was a bit worried at first, but so far everything seems good.
BTW: the Zippy K 4300 3S in my rustler with a mm 5700 combo it is barley controlable. I love it, it weelies on comand at almost any speed. Before I got any highspeed gps runs in I broke the chassis in half
oh, well a new one will be here soon.
-Brian