Yes, I generally charge again. But if when you flew yesterday you only flew one flight (say 15 minutes), then you can safely fly in a few days without charging. Some packs self-discharge as much as 1-3% per day. So after 10 days they might be discharged by 10 - 30%. (I've never experienced this great an amount, but I think I read this somewhere). My mind is never reliable enough to remember whether a pack was partially discharged, so when I know I might go flying, I charge overnight the night before. If I cannot fly and the next weekend rolls around, I charge again. repeated overnight charging (using the C/10 charger that comes with the system), does not seem to hurt the packs. I believe you could charge them once every weekend overnight and they would still work for many years. I have accidentally left packs on for a couple weeks and no apparent harm. All of this is with NiCd or NiMh packs charged at a low rate (50 mA).