I just got an ipv3 and I heard you are supposed to switch the batteries in place when its at 50% battery. is this true? thanks
Personally, I would not bother with this. What I would do for batteries in series is label the batts 'A' and 'B' and put 'A' on the left side once and then on the right side next time. If you have multiple sets of batteries, lable them '1A', '1B' and '2A', '2B'.
You should definitely keep these batteries in pairs and not use them by themselves in other mods.