I do use a timer, but it appears the TO sucks up more power than the T-34 did with the same power plants. The Apprentice I get 14 minutes off the 3S 3300 packs, but about 6 minutes is tops for the TO. My LT-40 flies 14 minutes on a tank, the 4*120 for 30 minutes on a tank, so a 6 minute flight is not very long. When done flying the packs are usually at 3.6v per cell, which is where I have my battery minder set, when a cell dips below 3.6v it starts to alarm, and what I find with the TO is that WOT right after takeoff will drop voltage on at least one cell below 3.6v on a full charged pack. Needless to say I put many more flights on my GP/Gas than I do on the electrics.