During heavy use periods, my iPhone 6 battery doesn't last the day. I'm looking at the battery cases available and curious if these actually reduce the life of the resident battery?
My understanding of rechargeable batteries was that they should be allowed to run down, and then fully charge. But that belief may be based on NiCad technology, and the newer LiOn may not have this issue.
It seems that if the phone has such a charging case, the case will function the same as just leaving the phone plugged in and 'topping off' the charge.