Hi i have 3 batteries.I flew one battery and i empty it to 15% and i forgot it in the drone for 4 days....So today i saw that battery was empty so i flew my other 2 batteries today until they empty ....So i put them all in hub to charge but only the 2 of the 3 batterys charge....The battery i forgot in drone for 4 days did not charge...So i took the battery that i was forgot in the drone put it back in the drone power it up and let it power off when battery empty completely,,,,All right i took the battery put it in the hub while the other batteries charging and then the other batterys stop charging and the battery i forgot start charge.This did not happen in the past......Any advice?My bateries have almost 100 charges each..

I’ve noticed this but I’m  not concerned. It appears the hub treats each battery similar to the way a conventional charger treats each cell in a battery, meaning it will charge tha battery with the lowest capacity until it reaches that of the other batteries on the hub. The charger operates at constant  current and variable voltage until the target voltage is reached, then switches to constant voltage , variable current until the capacity of the batteries is reached, then switches off.