Everyone else uses them as a pack. Everyone else charges them as a pack.
Not Completely true i'm afraid i have a pair me and my boy use them singly in mardaves and we charge our own that way as long as they are fully charged each. they will be balanced as a pair (ignoring negligible difference in chargers (if charged on different chargers) if used as a pair later and found to wildly out of balance then you more likey have a failing lipo that no balancing will remedy
no offence intended to anyone and quite happy to be put in my place and learn more about the black art of lipo tech
regards dave