I took advantage of a cold snap here in Fairbanks Alaska to test my new 3P in minus 40F (and C) and thought I would share some of what was observed. After reading at various forums that sudden onset battery failure was a potential problem, I elected to begin a hover test over a homemade 'Pastrana Pit' made of foam padding. I also programmed my C2 button to bring up the battery page to monitor battery temperature. Two new batteries with three flights each were used. Camera was operated in 4K as it produces the most heat, necessitating the tiny muffin fan on the camera module for normal operation.
The bird was initialized inside to try to offset warmup time. Barometer drift became apparent about 1 minute into the hover test, followed by a loss of video transmission about 30 seconds later that never returned. Around a foot of altitude gain per 45 seconds was the norm throughout the test. A 12 foot hover eventually produced a -16 foot reading. Battery temps were at 24C at takeoff and plunged as low as 14C. Taping the battery compartment gills off slowed cooling considerably; all arm vents and VPS vents were left uncovered. Surprisingly, the tiny muffin fan on the camera module seemed to run the entire time.
The bird was lowered to about 6-7 feet and a very significant gimbal oscillation was observed. It looked to be about a 120 cycles per second shake moving the camera about 1/3 inch. The camera recorded flawlessly and the oscillation was not evident when the video was reviewed. No icing was present on the blades or body(extreme cold takes all of the moisture out of the air) and inspection afterwards showed no apparent cracking of the rubber gimbal parts. Up/down camera movement was normal throughout although I purposely kept movement down to a few adjustments every few minutes.
Very surprising was the battery life: from 97% and 96% to 30%(which dropped to 18% in the minute between shutdown and running inside to thaw) both batteries produced 15 and 18 minute flights. The number 1 and 4 cells would drop into the red first, number 1 leading the way. This occurred just at the 30% warning, and 14C battery temp. I elected to land at that point. The batteries have each been charged 7 or so times since then and show no sign of holding a grudge. My P3 was purchased in December and I haven't done any updates but I think I may have the cold weather battery management upgrade on board already.
The clear air of minus 40F is a photographer's dream; if you can compose without video feed you can catch some stunning images. While I am not hoping for more -40F if it shows up I can test my 3P while waiting for pipes to freeze and cars to break down…...
The bird was initialized inside to try to offset warmup time. Barometer drift became apparent about 1 minute into the hover test, followed by a loss of video transmission about 30 seconds later that never returned. Around a foot of altitude gain per 45 seconds was the norm throughout the test. A 12 foot hover eventually produced a -16 foot reading. Battery temps were at 24C at takeoff and plunged as low as 14C. Taping the battery compartment gills off slowed cooling considerably; all arm vents and VPS vents were left uncovered. Surprisingly, the tiny muffin fan on the camera module seemed to run the entire time.
The bird was lowered to about 6-7 feet and a very significant gimbal oscillation was observed. It looked to be about a 120 cycles per second shake moving the camera about 1/3 inch. The camera recorded flawlessly and the oscillation was not evident when the video was reviewed. No icing was present on the blades or body(extreme cold takes all of the moisture out of the air) and inspection afterwards showed no apparent cracking of the rubber gimbal parts. Up/down camera movement was normal throughout although I purposely kept movement down to a few adjustments every few minutes.
Very surprising was the battery life: from 97% and 96% to 30%(which dropped to 18% in the minute between shutdown and running inside to thaw) both batteries produced 15 and 18 minute flights. The number 1 and 4 cells would drop into the red first, number 1 leading the way. This occurred just at the 30% warning, and 14C battery temp. I elected to land at that point. The batteries have each been charged 7 or so times since then and show no sign of holding a grudge. My P3 was purchased in December and I haven't done any updates but I think I may have the cold weather battery management upgrade on board already.
The clear air of minus 40F is a photographer's dream; if you can compose without video feed you can catch some stunning images. While I am not hoping for more -40F if it shows up I can test my 3P while waiting for pipes to freeze and cars to break down…...
