Even though I balanced charged my lipo the cells were still way out of balance and the charger never told me it was "FULL". It just timed out so when I took a reading it should one cell at 4.22V and the other at 4.12V. I thought nothing of it and took my DIY mini quad for a brief flight. I guess the voltage dropped below the ESC's low voltage cutoff and the quad plummeted out of the sky and slammed into a wall.
I wanted to share how I got my cell rebalanced. This assumes your cells are still good. If you can't get them to balance then don't fly with it. You may have a weak cell and it's not worth the risk.