I agree w/ Richard. Your lipo cut off setting may have been too low. you don't want to drain any lipo lower than 80% of your total capacitance or roughly 3.2v per cell. I typically look at the discharge rate and capacity / volume of lipo as a good guage or measurement of the quality of the battery.
For example: if two battery has the same dimensional size and weight (density), but one has higher capacity and discharge rate, it's obvious which is better quality battery.
Lower the quality of the battery, the higher the lipo cut off setting should be.
Ideal cycle for Lipo is to cycle by the capacitance, not by voltage of the battery, but since the voltage is easier to measure it's typically cycled 4.2v to 3.7v or .5v per cell, this way you maximize the performance and the life cycle of the battery.
For better quality batteries, you can drain them much lower (e.g. 2.0v per cell for Kong Power) and not damage or shorten it's life.