@TheSnowyPilot ,it is acceptable to put a label inside the battery compartment ,as a back up in case the one one the outside of the drone becomes detached ,i would not attach anything to the batteries of the Mini drones ,in case it got jammed inside the drone ,and prevented the battery from being removed
with regards to numbering your batteries it allows you to keep track of their use , and prevents you from using the same one over and over again ,i tend to fly mine in reverse order ,every other time i fly ,so thats 1-2-3-4 in one session then 4-3-2-1 the next time i go out,that way, say i went out with the 4 batteries fully charged ,then due to a change in the weather ,or some other circumstance that only allowed me to fly 3 of them ,till maybe the next day then i would use Number 4 first and so on so i am always using them in sequence ,it works the same if i only want to charge,and fly two batteries of the 4 on a given day i know that next time to use the two other numbers first
i know what you are thinking ,i am being obsessive about my batteries ,but hey it works for me ,and thats all that matters