GadgetGuy's Final P4 Flight
I decided to give the P4 one final test to see if I could squeeze any more battery life out of it by flying only in Atti mode, which is the mode DJI used to arrive at their 28 minute flight time.
I have already given up on the P4 GL300C transmitter, and, instead, again paired the P4 with my FPVLR v2 modded GL300A with 3W boosters, just like on my second flight.
Once again, I could not top off the P4 battery above 95% before launch, as the new charger refuses to top off a slightly used battery, unlike the P3P charger. No matter whether I turned on the P4 battery
before connecting it to the charger, or
after connecting to the charger, in both cases, the battery immediately shut itself off, and stopped the charging process.
So, starting with the P4 battery charged as high as I could at 95% upon launch, with OAS turned off, front LED's turned off, channel 30 set on the hack, 4 Mbs set on the video transmission, I took off and immediately switched into Atti mode, flying in Orange instead of Green throughout the flight. During bootup, the gimbal made disturbing squealing sounds, but it has done that every other time, too, with no apparent side effects.
I flew as I always have, at full throttle, and speed was between 30 and 40 mph throughout. 2 to 3 second video dropouts started at the 3 mile mark, while flying at 40mph, which meant I had to stop until it recovered each time, but in Atti, it just drifts. No active braking, so no battery power consumed, like it would have been, in P-GPS or Sport mode.
However, battery was being consumed faster than I have
ever seen before. I quickly turned around and headed for home. On the way back, the gimbal briefly locked up and stayed tilted at 45° for several seconds, while the app displayed a "maximum gimbal angle exceeded" warning! Very disconcerting! I finally landed with
only 7% remaining battery and had to fight hard to keep the aircraft aloft, during autoland after 10%, while maneuvering to a safe handcatch. I had flown 39,175 feet, but my
total flight time was only 12 minutes, 19 seconds! She's a speed demon, but at a
huge battery burn, and props are often in the frame, ruining the video. The "maximum gimbal angle exceeded" error is a new one (which also ruins a continuous video), and should never happen in Atti mode, with no braking going on. Never seen anything like that on my P3P.
1. My first P4 flight was
16 minutes, 14 seconds and 30,000 feet total with the stock TX in all modes.
2. My second P4 flight was
14 minutes, 40 seconds and 40,750 feet with my FPVLR in P-GPS mode.
3. My third and final P4 flight was
12 minute, 19 seconds and 39,175 with my FPVLR in Atti mode
Flight times are getting
WORSE with each flight,
not better, and even Atti mode
cannot improve them!
DJI promised flight times
exceeding 28 minutes, but is now actually
delivering 12 minutes! Even TWO P4 batteries in parallel won't deliver 28 minute real world flying times on this aircraft. Also, the crappy video transmission from the aircraft cannot even be fixed with a transmitter mod.
Because I was so demoralized after this last P4 flight, I pulled out my W323 P3P, with its battery mod, and hooked it up to the same FPVLR setup
just used with the P4.
I then flew my P3P directly
over the same route as the P4, and just kept going, and going, and going! Flight time was 25 minutes, 37 seconds, over 66,000 feet, and I still had full video and control at 5.2 miles away, and returned with 15% remaining battery.
Final Conclusion: My W323 P3P rocks! This
particular P4 sucks! My DJI 7 day return period for manufacturing defects ends tomorrow. Shipping the P4 back to DJI in the morning! Already have my return shipping label! Plenty of manufacturing defects, between the defective battery, the defective charger, the defective control, and the squirrelly gimbal! I only needed
one. I found
four!
See also:
GadgetGuy's First Flight Impressions of the P4
and:
GadgetGuy's Second P4 Flight Impressions