GadgetGuy's Final P4 Flight

[MikeK]

Yup. Some of foolishly ordered directly from DJI. Apple gives you 14 days to return with no questions asked! Amazon is 30 days! DJI is only 7 days with a manufacturing defect, if you have flown the aircraft! Shame on DJI, for lying to customers trying to return, telling them they cannot return, if they have ever flown it! NOT TRUE! Every P4 has multiple mnufacturing defects, based upon the claims on the box! The battery is defecive and will not deliver 28+ minutes. The transmitter is defective and loses signal after 1.3 miles, and won't ever deliver 3.1 miles! The gimbal squeeks and squeals like a stuck pig, upon bootup, and during movement of the P4 after turning on the battery, and gets stuck in flight at a 45° angle, generating "maximum gimbal angle exceeded" errors! Lastly, the charger, unlike the P3 charger, won't let you top off a 95% charged battery, even if you turn it on before or after plugging it into the charger. It immediately shuts off, and stops charging.

Wow.

 

[Jussaguy]

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

Dang, it sounds like you got a lemon of a lemon.

 

[GadgetGuy]

The p3p did not do the 3.1 miles either in his test.

True, but the P3P control range was still some 20% farther than the P4. The P4 control range is still worse than the P3P, which is a step backwards, not forwards, as a result of the "enhanced" Lightbridge.

 

[GadgetGuy]

Dang, it sounds like you got a lemon of a lemon.

Apparently, but not enough to "sour" me on the P4's potential!

 

[TheLightSpeedz]

Apparently, but not enough to "sour" me on the P4's potential!

So you returned it?


Sent from my iPhone using PhantomPilots mobile app

 

[GadgetGuy]

So you returned it?


Sent from my iPhone using PhantomPilots mobile app

Yes, to DJI, for a full refund, so I can repurchase elsewhere, with a more liberal exchange and return policy.

 

[Jussaguy]

Yes, to DJI, for a full refund, so I can repurchase elsewhere, with a more liberal exchange and return policy.

Well done. Although the irony is you returned it to DJI.

 

[GadgetGuy]

Well done. Although the irony is you returned it to DJI.

Indeed! DJI doesn't even offer customers buying directly from DJI the same DOA return within 14 days, that DJI offers to their Dealers, and Apple!
That's just wrong on so many levels!

 

[John Locke]

True, but the P3P control range was still some 20% farther than the P4. The P4 control range is still worse than the P3P, which is a step backwards, not forwards, as a result of the "enhanced" Lightbridge.

I think if you set the transmission quality to 4mbps on the P4, it performs about the same as a new P3P today. Granted, it's not the same as older P3Ps, but it still works rather well with a windsurfer installed, a mere $25 slip on antenna accessory. I got 15,000' last week without a hiccup on the video feed.

 

[GadgetGuy]

I think if you set the transmission quality to 4mbps on the P4, it performs about the same as a new P3P today. Granted, it's not the same as older P3Ps, but it still works rather well with a windsurfer installed, a mere $25 slip on antenna accessory. I got 15,000' last week without a hiccup on the video feed.

I always use 4mbs and a windsurfer on my stock Tx's, and did the same on my P4 Tx. Supposedly, some early P4 Tx's were defectively underpowered. Mine must have been one of those. It lost signal at 6,700 feet and did a RTH. When paired with my FPVLR modded Tx, it easily reached 3 miles, but the 12 minute battery life prevented me from testing further.

 

[Tobrouk]

I get a constant 22 min out of my batteries! No ATTI and no sport mode... battery down to 15%...

 

[GadgetGuy]

I get a constant 22 min out of my batteries! No ATTI and no sport mode... battery down to 15%...

That's like driving your Ferrari to the grocery store. What a waste!
This baby was built for speed, like a Ferrari, and no Atti or Sport mode is wasting its potential. The 28 minute, larger battery was supposed to support that speed. Alas... The battery life was "greatly exaggerated"...

 

[MDodd]

That's not a good analogy , you can use a Ferrari for going to the shops and you will get good mpg, if you choose to race it at the track it will get bad mpg . I beleive you are being unfair expecting 28 minutes at max speed , I don't recall seeing anywhere in dji's marketing that you could get 28 mins at max speed ?

 

[Jussaguy]

That's not a good analogy , you can use a Ferrari for going to the shops and you will get good mpg, if you choose to race it at the track it will get bad mpg . I beleive you are being unfair expecting 28 minutes at max speed , I don't recall seeing anywhere in dji's marketing that you could get 28 mins at max speed ?

While I agree with you, I have to say, because I have a problem, that you would actually get much better mpg on the race track.

 

[GadgetGuy]

That's not a good analogy , you can use a Ferrari for going to the shops and you will get good mpg, if you choose to race it at the track it will get bad mpg . I beleive you are being unfair expecting 28 minutes at max speed , I don't recall seeing anywhere in dji's marketing that you could get 28 mins at max speed ?

I wasn't referring to the mpg but the speed. The Ferrari was designed for speed, not economy. No one buying a Ferrari cares about the mpg. The big selling point of the P4 over the P3 is the speed, and the claimed 20% increase in battery life over the P3. The P4 delivers on speed, but I certainly did not expect only 12 minutes in Atti mode out of a new P4 battery at 97% down to 7%! The P4 speed is only 10mph faster, but the flight time is half of the P3 battery at full speed! No one is getting 28 minutes, even hovering 3 feet off the ground on a P4 battery!

 

[Jussaguy]

I wasn't referring to the mpg but the speed. The Ferrari was designed for speed, not economy. No one buying a Ferrari cares about the mpg. The big selling point of the P4 over the P3 is the speed, and the claimed 20% increase in battery life over the P3. The P4 delivers on speed, but I certainly did not expect only 12 minutes in Atti mode out of a new P4 battery at 95% down to 7%! The P4 speed is only 10mph faster, but the flight time is half of the P3 battery at full speed! No one is getting 28 minutes even hovering 3 feet off the ground on a P4 battery!

A couple things, contrary to popular belief, hovering uses more power unless there is virtually no wind.

Secondly my battery tests and these have been under very windy conditions here in SoCal started with the 19 min vid.

Some were hovers, some were speed, but they were all around 20-25 mins. The 16min one I brought in after chipping a tree.

 

[GadgetGuy]

A couple things, contrary to popular belief, hovering uses more power unless there is virtually no wind.

Secondly my battery tests and these have been under very windy conditions here in SoCal started with the 19 min vid.

Some were hovers, some were speed, but they were all around 20-25 mins. The 16min one I brought in after chipping a tree.

I have no quarrel with your results, although they are certainly unique. Mine were vastly different, as are everyone else's. Perhaps your battery exceeds the stated mAh, while most others are well under. I got 16 minutes, 15 minutes, and then 12 minutes entirely in Atti mode mode, as that was the same mode DJI used for their 28 minute flight time. Hard to say how to explain the gross discrepancies. YMMV.

 

[MDodd]

I have a P4 and seem to get 24-25 minutes while flying with my son and his P3A who gets about 19 minutes flying at the same time, same type of flight, not scientific , but just what I have found , and if I want to go fast I get my 250 racer out, which was built for the job .
My P4 range has never been tested, as in the UK you have to remain in visual contact , and my eyesight must be bad as I lose sight at around a 1000 meters .

 

[Jussaguy]

I have no quarrel with your results, although they are certainly unique. Mine were vastly different, as are everyone else's. Perhaps your battery exceeds the stated mAh, while most others are well under. I got 16 minutes, 15 minutes, and then 12 minutes entirely in Atti mode mode, as that was the same mode DJI used for their 28 minute flight time. Hard to say how to explain the gross discrepancies. YMMV.

Yeah, weird!

I just found a dent in mine and I had a flight where I left the gimbal clamp on the whole flight so I was thinking of bringing her back and replacing at Apple since I can. Should I not?

One of my two bats btw is already down to 99% life which I don't remember my p3 bats doing that until after some time. That was only after like 25 flights or so. Maybe I'm running it down to low.

 

[MDodd]

The most efficient flight will be in slow forward flight , followed I would guess by hovering in ground effect ( which with something with such small rotor diameter is probably 2 inches off the ground ! ) I have found if you fly faster ( anything faster than P mode with collision avoidance on) it does effect battery life badly , but I did expect this to happen , as I was always taught you can't get something for nothing.

I actually don't think the P4 was built for speed , it can do it, but like an SUV will be really inefficient at high speed .


And a Ferrari definitely doesn't have better mpg around a track unless you are cruising at 50-60 mph with no one else around , but then who would want a Ferrari anyway.