Dual Lipo problem
Have 2 separate 2100 mah Lipos on an extra 300 50cc. Each goes through separate regulator (part of each switch) and then into its own battery port on a JR 921 rx. The two battery packs are not the same brand. After say three 12 min fights, one battery is down to ~7.9v or so and the other has not gone down, ie reads ~8.35v. Recharging, one pack takes ~400ma and the other with about ~50 ma. What is going on here ? I fear if I continue to fly, one pack will go too low and the other pack won't supply current at that time and the plane could go down. Any ideas on what is the CAUSE (not the solution), which is probably to get A123s.