If your battery was down to 14.5v after ten minute easy flying, I'd say the battery is faulty if you are certain you had a full charge.
The QC on these batteries is probably not the best, so unless you are very confident you have good batteries, I would be landed at 14.7v. While flying, watch the rate of voltage drop, because it can be quick especially where it nears the point of the knee in the voltage curve.
Do not go by the claims of flight time, or wait for battery warning.
Can you check the internal resistance of each cell?? I am curious.
My 3 batteries are all sitting at 3milliohms per cell and working flawlessly after about 1 hour flight time each so far. I am landed at 14.6-14.7 volts, not less.
Just my suggestions