The 9.6V will still get you more motor revs. The 7.4V may be lighter with the same amperage rating. 11.1V will give you the best performance.
Lipo alarms is just that, a alarm. Get one that has the ability to warn you when it hits higher than 3.3V. AEG's can pull the voltage below the safe 3V, the point of no return. Once the alarm sounds, STOP.
Charging in your garage unattended will still burn down your house. I have my Lipo packs sitting inside ceramic bowl elevated off the table surface with another ceramic tile. If the Lipo bursts, nothing to burn but itself. Keep an extinguisher around. I had a Lipo go into flames last year.
Last edited by SuperHog; November 2nd, 2012 at 15:32..