hi,
I have two AW 18650 batteries and a Pila charger, is it best to wait till the battery if completely empty before recharging or can i recharge when they are half full?
Don't run a li-ion cell all the way down if you have a choice. I swap cells when they hit about 3.7 volts (which puts them somewhere between 40% and 60% spent, depending on whose numbers you believe).
Are they protected (red stripe) AW batteries? If so, they will shut off when they reach 2.8V if I recall correctly.