Chad - no, that’s not right. You want to find the lowest voltage cell of the 3 and ONLY charge that cell to the same voltage as the other 2 cells. You NEVER want to charge the battery at 12v trying to ‘condition’ the pack. Here’s the issue, and understand this clearly, if you have one cell at a low voltage, let’s say 3.5v (fully charged LiPo should be 4.200v) and you charge the pack at 12v this will OVER CHARGE the good batteries with a real potential of causing a Fire. You only want to TRY and charge the cell that is not charging properly. This is called balancing the pack - and good chargers do this by design.
In the picture above, assuming it’s correct, if you measured cell 3 as low, you would charge ONLY THAT CELL at perhaps 5v for only a minute or two. You do this by putting the charger negative to the +9 terminal and the charger positive to the +12 terminal. That way only that cell gets a charge, not the complete battery. After a few minutes stop the charge and try the Yuneec charger again. If it does not work forget trying to condition the pack. Put it in salt water for 24 hours to discharge it and dispose of the battery correctly.