Using my mod for low battery by pass, I tried some LG 18650 3000Mah cells.
Cut to the chase, still not worth it.
Got around 2:30 mins before S6 started to behave erratically because the voltage on pack got to around 6.6 – 6.8 volts and at that voltage the esc does not work correctly.
Starts erratically moving up and down and very unresponsive.
Only way to get around that is to wire in a third party esc that works on low voltages that could take advantage of 18650’s. Maybe I will do that at some stage.
Still I know for sure as things stand , 18650’s are not a viable option on this craft due to how many amps this S6 pulls and also the low voltage limitation of the stock esc board.
I have some lower kv motors on the way from Banggood that might prove more efficient to get some more life from this old quad with standard lipo’s.
Have fun