"Topping Off" my battery?

[pianoflyer]

My procedure for charging my batteries has been to get home from flying, plug the battery in and charge until the lights go out. The next time I go to fly (let's say the next day or a couple of days later) when I check the battery I get 4 lights denoting full. But if I plug it in (with the power on, as advised ny the manual, since it has more than 75% charge) it will seem to keep charging for about 5 minutes before the lights go out. I assume it's discharging a bit overnight and I am"topping it off" . Is this a good idea and am I getting any more flight time since I do get the 4 lights when I first check it.
Thanks,
Steve

 

[voodoo]

Even though you see 4 lights, it's probably not 100% always. You may be around 95% but that extra "top off charge" may give you that extra 30sec - 1 min of comfortable flight time.

Topping off Lipo batteries is fine. Discharging a Lipo all the way to 0% (impossible for safe P2 flying I know) is exactly what you do not want to do. There is a relationship between discharge amount and the life cycle of a battery. If you only use from 100% to 90% of a Lipo, you can get immensely more discharges as you would going from 100% to 10% each time. This may seem straightforward upon hear it, but many people worry that charging a lipo that isn't fully discharged is actually damaging it. This is untrue.

 

[Meta4]

If your battery is >90% charged, the lights won't come on and it will appear to be 100%.
You can get the last <10% in by turning on the battery (lights come on) and then plugging it into the charger.