I held back on this one but if a battery is not inserted deeply into the stock charger the balance tsps will not make contact and you’ll end up with a flashing blue light. The same can happen if the contacts are dirty.
As NorWes mentioned, the three contact points between the outer flat contacts are there for balancing the individual cells during the charging cycle and not employed in any way during flight. There is no feature inside the aircraft than can connect with them.
The battery has multiple cells to provide enough voltage to power the system when all are used in combination. Individual cells are not used to power specific functions. I can’t think of any system that uses multi-cell batteries to do that. Attempting that would be extremely difficult as it would be necessary to monitor individual cells to provide a means for the operator to terminate a flight before any individual cell discharged to a critical level and destroyed itself.
As systems do employ features that utilize different voltages such as low voltage components like compass and GPS, mid voltage components like the RC receiver and flight controller, and higher voltage components like motors and ESC’s, devices like UBEC’s are employed to step down the voltage from the battery. Such devices are essentially volt limit regulators. If anyone ever tells you that each cell of a multirotor battery is used to power individual components, kindly smile and walk away while vowing to never listen to or ask technical advice from that person again. It will save you a lot of confusion.
As for chargers, it’s always better to invest in a good after market charger and power leads to take better care of your batteries. You’ll also be able to charge them faster than stock kit chargers will. Do take a little time to read the charger instructions and review battery care techniques at websites that specialize in battery information and care before using an after market charger.
