Hi everyone. I'm a bit concerned about the voltage, amperage and temperature of the odd motors on this flight and the one before it. The day before this flight, the copter was set up the same way, carrying the same camera (5DMKII), balanced and the readings were fine. The next day, flying at the same location with the exact same setup, these were the results. Wind conditions were 5mph both days, temperature in the mid to high 80's, humid, compass was calibrated the day before. I flew it again today with the sony CX760 and everything looks normal. Any idea of whats contributing to high readings on odd # motors? GPX file is attached. Also, averaging 3 min/30second per flight before the low voltage warning? That's not right at all. QC 8000mAh. Alarm set to 14.4v Weird.... Flight date: 6/21/2013 8:17:16 PM Flight time: 8:17:16 PM - 8:21:01 PM (225 secs, 00:03:45) Batt. time : 228 secs, 00:03:48 Elevation(GPS) : 0 17.94 50.21 ft (min/avg/max) Altitude(Barom.): -4.59 24.06 58.56 ft Vertical speed : -6.17 -0.18 9.48 ft/s Max speed : 8.6 mph Max target dist.: 0 ft Sats : 8 10 12 Voltage : min. 14.2, max. 15.7 V Current : 14.8 71 99.9 A Wattage : 222 1066 1448.55 W Capacity: 4511 mAh Motor1: 1.7 11.4 17.6 A Temp: 91 145 187 °F Motor2: 3.2 6.8 10.7 A Temp: 90 127 149 °F Motor3: 1.0 11.8 15.7 A Temp: 86 147 169 °F Motor4: 2.2 6.5 10.6 A Temp: 81 131 147 °F Motor5: 4.4 11.2 14.9 A Temp: 86 156 180 °F Motor6: 2.7 6.0 11.4 A Temp: 81 124 138 °F Motor7: 5.6 10.8 16.9 A Temp: 82 142 171 °F Motor8: 3.5 5.5 7.9 A Temp: 88 118 133 °F Magnet Field: 101 105 114 % (ok) Magnet Inclination: 63 65 71 deg Errors / warnings: FC-Flag "LowBat" (5) occured 11 times!
Looks like the battery wasn't fully charged -- max. voltage was 15.7 volts -- and that would have been measured when you first connected up the battery and before you started the motors. There may be other issues, but that's what appears from the summary....sorry, haven't had a chance to look at the GPX file, Chris. Andy.
I noticed that too, but I charged the batteries the night before and checked the charge once off the charger...all batteries showed between 16.4 and 16.7, all cells within range. I use the hyperian 720i Duo.
I'd treat that battery with deep suspicion -- because the implication is that it self-discharged overnight and that's a Bad Thing. Andy.
I'd try again but read the voltage just before you plug it in to the copter. Maybe you are using a heavy lens?
I am...a 24-105, balanced. The day before the files looked fine, same setup. And then there are those who fly REDS with various lenses...
The 114 in magnetic field looks a little high. Ziggy once told me that if half your motors are hotter it could be a compass calibration problem even though it doesn't show any errors. I know that doesn't make any sense if you flew the same location the day before.
Dave, There were differences between the two days. I was flying at a motorcycle event/stunt show (not over the crowd). The previous day the was a test run with some of the stunt riders. The metal gates surrounding the track were not up yet and there were just a few bikes around. The day of the event there were thousands of motorcycles, vendors, food trucks, a DJ within close proximity and the metal gates were up around the track where I flew over. Funny you mention this. As the day goes on, my readings get worse and worse. That GPX file was the flight during the show where the track was surrounded by spectators, many of which had cameras and cellphones running positioned on the outside of the metal gate. Not to mention a few thousand motorcycles parked within stones throw (more like a lob). Possibly a lot of metal, cell phone and electrical interference? Just a thought...