hello, is it bad to charge a battery when its still has 2 stripes full or should i always wait until the battery is complete empty ! i want to have sometimes a full charge when i have a shoot the next day so i can not always wait until the battery is complete empty.its a 1d mark 4 battery
If you're using a Canon battery, with a Canon charger, it will manage the battery and only charge when appropriate. If you tried to charge it with it only down 5%, it wouldn't charge at all, from what I read a few months back.
I never wait until my batteries are empty...I just re-charge them after every outing no matter where the charge level is. These batteries now are "smarter" than what we learned when rechargeable batteries first came out a while ago. It is not bad for them nowadays...well, at least for the Canon ones but I am certain it is the same for every make.
As noted Lithium-ion batteries can be re-charged virtually at will. Two things to consider though: 1. They like to be exercised regularly. They don't like just sitting around. 2. Every now and then it is a good policy to fully discharge them and re-charge. Canon has this facility on the 1D4 and 1Dx charger by "calibrating" the battery.