2 cool cheap item's i have for my lipo's and starter box is a basic cell checker and a battery monitor that has light's and will audibly warn you if the pack is getting dangerously low....and for under 15$ for the pair....there worth having around
Monitor
http://cgi.ebay.com/Maxpro-4S-Lipo-B...d=p3286.c0.m14
Tester
http://cgi.ebay.com/Li-Po-Battery-Vo...d=p3286.c0.m14