Lost my M2 Pro with DH- weird speed limit descend

[cmunozs]

If it were a slightly higher fit I might consider very slightly sanding/shaving some plastic to get a proper fit.

I bought a used M2P from eBay earlier today. We'll see how it is when it gets to me, but I will upload a video of how these big batteries fit into the drone. It will be interesting to feel the difference when I am already used to do it with the drone I lost. Don't think it needs sanding. Might help, but is not really about that.

I'd be wary of third party batteries in general.

I believe the Aliexpress batteries were made from original DJI batteries. Nevertheless, they are still third party.

Too bad we don't know why the rate of decent was so slow compared to what you were used to.

I strongly believe, after what was previously discussed here, that the reason for my "event" happened because the battery not fitting well in the drone or getting loose in flight.
The speed I was used to flight up and down with this drone was 9m/s (32km), again, either ascending or descending, but when this happened, I noticed that the speed dropped to 3m/s when descending. I didn't try, of course, to ascend to test if that was equal. I double checked it in the DJI Go 4 app.

How many of the AE batteries do you have @Conservative Nihilist ? Are they all equally built? I remember there were two different suppliers when I bought them and two different sizes in mAh. I bought the biggest, but just one.

 

[Conservative Nihilist]

I bought over ten Ali Express extra-range batteries in my most recent order, with a further 3 as my initial purchase. I'm including my order list here to show the less-known battery upgrade for the DJI Air 1 which boosts the mediocre 15-minute flight time of that first-generation DJI Air to 23 minutes which is sufficient for that antique DJI bird to cover 6 miles round-trip distances Two additional humpback batteries for the Mavic 1 Pro from the same order are not shown in this screenshot.



The performance of these batteries has generally been true to the product description claims. Mavic 1 Pro and Mavic 2 Pro drones fitted with these batteries fly for a respectable 32 minutes at 27 mph before landing with 20% battery power remaining after covering between 11 and 13 miles in total. On landing the battery contacts were warm but not too hot to touch, indicating normal engine operation despite the longer duration of the flights to which the drones are subjected.

Within 2 years I lost THREE of the Ali Express batteries, with the same number of Mavic I Pro drones in total also written off as outright losses. Every single one of those crashes occurred because of my initial failure to recognize the need to utilize a battery retention strap as a safeguard against the effects of heat on the drone's battery retention clips.

With the Ali Express super-batteries exonerated in all my drone losses thus far, this report would not be complete if I did not mention the alarming fact that TWO of these hitherto flawless Ali Express batteries recently delivered in the post, turned out to be absolute duds that would not take a single charge. My dismay was compounded when I discovered that, unlike eBay where contact between vendors and their customers is encouraged, I could find NO means of contacting Ali Express vendors to register my displeasure and perhaps request replacements.

With this very recent tarnishing of a previously unblemished performance record using these extra range Ali Express DJI-compatible drone batteries, I can now only recommend Ali Express DJI-style batteries to drone owners who are willing to take a calculated gamble in terms of their monetary outlay, bearing in mind the near impossibility of contacting Ali Express vendors once the purchase payment has changed hands. As a gambling man of good repute, I will still patronize Ali Express because thus far it is the only online store where a variety of DJI-compatible, plug-and-play extra-range batteries are consistently available.

 

[Conservative Nihilist]

When my drone flying life is over and I must come up with some words of profound wisdom to be carved on my gravestone, those words will be carved as follows: " Always use a zip-tie to secure your older DJI Mavic Battery."

Here is my Mavic 2 Zoom decked out in full formal attire complete with a tastefully selected necktie.



To the left of this frame, you might notice my trained attack civet cat conducting his usual tour of inspection as day breaks here by the Equator. For such a small beast, he crunches chicken bones with alarming alacrity.

 

[cmunozs]

Hi all!
So, I finally got my new Mavic 2 Pro that I bought from eBay a while ago. Took some time to het to my hands, but finally it is here. Drone is in perfect condition, maybe even better than the one I previously had, which was also second hand.
It came with a very old firmware, so I updated it just because all the latest firmware versions can be used with DH too. Upgrade it and calibrated all the necessary things to get it properly working. And also applied DH right away, which what I was interested for in the first place. All good.
Went for a first fly and I was having the same problem I had last time, previous to my incident. Battery showed 0 volts, but I was sure again it was fleshly charged. Switched batteries and now I got it up un running correctly.
I flew thousand meters up. No problem. Test completed, but the battery issue keep me thinking it the error was not coming from the drone, but the batteries themselves. So started checking them one by one, until I see what the problem is and was:


This was easy to spot, but I had a couple more that was not easy and just a bit of the plastic was cracked and loose So what I think it happened during my flight was that I used one battery that was already cracked and while I was flying, vibration made the electronic parts somehow loose proper contact with the drone and miscommunication, maybe those small pieces of plastic that felt from that part, got into the wrong place... who knows. That in the end, turned out to be the reason why I lost power, made my drone decent slower than usual and eventually, lose it.
This will continue to be a theory until I find my lost drone, which might be still possible. but it is unfortunately a good one, I believe.

I, for sure, will not continue using those broken batteries with the drone, even though the drone recognizes them ok after I bend back those contacts. They still can be charged and used as a power bank IfI want to.
Good thing is that my Ali express battery still intact. Now, I might get a few more of those...

Why the contacts got broken, you may ask? Well, I think it is due to two reasons: 1.- Batteries are getting old now, and that part is just plastic. Putting in and out of the drones and chargers wears them out, eventually and looking at the plastic itself, it is not as strong as one thinks and 2.- I believe the chargers from aliexpress I got a while ago, were too tight to fit sometimes, which got me to force them without measuring how bad this was when putting them on the charger.


Chargers are good, don't get me wrong, but I will be more careful from now on.

Extra thoughts: Aliexpress battery still gets a pretty tight fitting in this drone, same as previous one, but works pretty good.
Might be a good exercise to check your battery connections on any other drones you have. I did not think this was a possibility, so I did no look for it before. Now I know and I'll keep checking for something like this in every drone I own.

PD: Descend speed is good now

 

[Conservative Nihilist]

I need to get my magnifying glass and pay closer attention to the contacts of my drone batteries. Already I have seen one Mavic 1 Pro vanish without a trace, had a second M1P crash, along with a Mavic Pro Platinum that crashed, all most likely due to battery detachment since I only recently learned about the zip tie fix.

Now I know the battery contacts require close scrutiny before each flight. Thanks for this infiormativce post C Munoz, and for the clear photographs that illustrate the battery contact breakage so well.

 

[Felix le Chat]

Hi all!
So, I finally got my new Mavic 2 Pro that I bought from eBay a while ago. Took some time to het to my hands, but finally it is here. Drone is in perfect condition, maybe even better than the one I previously had, which was also second hand.
It came with a very old firmware, so I updated it just because all the latest firmware versions can be used with DH too. Upgrade it and calibrated all the necessary things to get it properly working. And also applied DH right away, which what I was interested for in the first place. All good.
Went for a first fly and I was having the same problem I had last time, previous to my incident. Battery showed 0 volts, but I was sure again it was fleshly charged. Switched batteries and now I got it up un running correctly.
I flew thousand meters up. No problem. Test completed, but the battery issue keep me thinking it the error was not coming from the drone, but the batteries themselves. So started checking them one by one, until I see what the problem is and was:
View attachment 181483View attachment 181484

This was easy to spot, but I had a couple more that was not easy and just a bit of the plastic was cracked and loose So what I think it happened during my flight was that I used one battery that was already cracked and while I was flying, vibration made the electronic parts somehow loose proper contact with the drone and miscommunication, maybe those small pieces of plastic that felt from that part, got into the wrong place... who knows. That in the end, turned out to be the reason why I lost power, made my drone decent slower than usual and eventually, lose it.
This will continue to be a theory until I find my lost drone, which might be still possible. but it is unfortunately a good one, I believe.

I, for sure, will not continue using those broken batteries with the drone, even though the drone recognizes them ok after I bend back those contacts. They still can be charged and used as a power bank IfI want to.
Good thing is that my Ali express battery still intact. Now, I might get a few more of those...

Why the contacts got broken, you may ask? Well, I think it is due to two reasons: 1.- Batteries are getting old now, and that part is just plastic. Putting in and out of the drones and chargers wears them out, eventually and looking at the plastic itself, it is not as strong as one thinks and 2.- I believe the chargers from aliexpress I got a while ago, were too tight to fit sometimes, which got me to force them without measuring how bad this was when putting them on the charger.
View attachment 181486View attachment 181485

Chargers are good, don't get me wrong, but I will be more careful from now on.

Extra thoughts: Aliexpress battery still gets a pretty tight fitting in this drone, same as previous one, but works pretty good.
Might be a good exercise to check your battery connections on any other drones you have. I did not think this was a possibility, so I did no look for it before. Now I know and I'll keep checking for something like this in every drone I own.

PD: Descend speed is good now
View attachment 181487

I managed to bend one of the battery contacts using the standard DJI brick (not being as careful as I should have been... lesson learned), but the design of that Ecoflow Powerfly charger is poor - I can see how the damage to your cells occurred. The battery rebate shoulders are way too low

 

[Rchawks]

I'll be more careful to check this. I always check for swelling I'll add this to the list.