Originally Posted by
Plutonix
Decidedly bad advise.
Li Ion cells are typically rated for 300 charge cycles before they reach 80% capacity. Cheap ones probably less, but it is listed on their data sheets. A deep charge counts the same as a or topping off charge, so it is better to use a pack until you get a low power signal (or ~2.7V/cell) rather than topping it off.
I think you'd better read up on LiIon batteries a bit more. That's not correct. It's not very good for LiIon cells to run them completely down every time. If you can charge them at about 50% depleted every time, you'll get more total amp hours out of the batteries over their lifetime than if you run them down to recommended minimum charge every time (or even very frequently).