ORIGINAL: afterburner
I just don't see the point. You can hit these packs at 10 amps if need be and a fully discharged 2300mah pack would be charged in like 10-15 minutes. If you let the battery get to that point you probably would have lost the plane anyway. Best thing is to do what others have said. Get a baseline on per flight usage and leave a nice cushion to be safe.
Marty
Yeah, I have to agree with Marty, Chad and Vincent. - one of the best things about the A123 chemistry is being able to super fast charge them and always have a boat load of life in the pack without the down time of a typical charge. When in doubt, charge it while chatting or listening to an Ipod tune, then go fly. It's a very quick charge and cheap insurance to always operate close to full capacity.