RE: ESM Dauntless
I didn't double check my batteries before I took off. I charged the night before and I think I charged the ignition battery twice. Instead of charging them and putting them in the plane as I go, I laid the charged battery on the bench next to the RX battery then went back in the house to help my wife bring in some stuff from the car. I came back out and plugged in what I thought was the RX battery and charged it then put them both back in the plane.
I also didn't bother to check to see what the charge on them was at the field (shame on me). I took off and flew for a while and all was great until I made the turn on final and hit the flaps. With all the other control inputs the flaps were just too much and the RX went to failsafe with the low voltage. She went straight in from about 50 -75 feet. The airframe is totaled but most everything else is good.
When I checked the batteries one cell on my RX battery was @ 3.04V and the other was at 2.85V w/ no load. They dropped to 2.75V and 2.2V under 4 amp load. I did charge it back up (I thought it would fail because lipo's aren't supposed to be that discharged) and it took the full charge. It was an 1800 2 cell lipo and held 1810mAh. Needless to say, this one is scary and won't be going in the new build. I'm even considering firing my flight crew.