Hiwayman,
Good news! I think I may have some information you have been looking for!
I'm really glad you brought up this issue as I noticed the same problems last year with some of my
Mavic 2 Pro batteries. I have not had any issues with any of the subject batteries performance-wise, and the oldest battery with the issue was manufactured in 6/2019 has 83 charges to date. Battery status for all batteries is normal from inside the DJI GO4 app and the cells are all pretty close in voltage at full charge. No swelling whatsoever with all of the batteries.
I have 7
Mavic 2 Pro batteries with production dates from 1/2019 thru 11/2019 and 4 of the 7 have similar issues with the connecting tabs. I use the DJI single port charger that came with the
Mavic 2 Pro and both a Yx and an FstopLabs branded aftermarket 3 port charger, one of the many blue ones out there, which are nearly identical. I have inspected each battery's connector tabs. I've examined all of the battery charger connector spades as well as the
Mavic 2's onboard battery connector spades and had some interesting findings.
Of the 7 batteries I own and use regularly, I'll refer to them as #1-#7, the first being the original battery in the
Mavic 2 Pro box, and the last being purchased almost a year later, #7. Batteries #1, #2, & #6 had no visible deformities or damage to the connector tabs. Batteries #3, #4, & #7 had damage on one connector tab. Battery #5 had deformities or damage on two connector tabs. First, I just want to say that I did not inspect the contacts upon receiving the batteries new, so I can not say with any certainty that the connector tabs were like that from the factory. The first photo shows normal connector tabs. The others show connector tabs with the damage issues. Pardon the lack of lighting/focus on the connector tabs as they are pretty small.
The
Mavic 2 battery charger connectors, DJI, Yx and FstopLabs have a corner that is dog-eared for indexing, not sure what the technical term is, so I'll just say for this discussion that the dog-ear is on the left. There are 10 vertical spade type connector pins which fit into the batterie's connector tabs, and for this discussion, let's say you would call the first contact spade to the left "A" and going alphabetically to your right on up to the 10th spade which we would call "J". I noticed that on the DJI brand charger of the 10 spades, A,B,C, & D are raised about a full 1 mm as compared to the E-J spades. Examining the
Mavic 2 drone battery compartment connector, the spades A-D are also raised about 1 mm.
Now when I examined both the Yx and FstopLabs chargers I found something interesting. The height of the connector spades are not raised in the A-D spades and also the heights and alignments of all the spades were not as uniform as the DJI connector spades. With two of my 4 subject batteries the bent connector tabs were at connector tab "D" and 2 were bent at connector tab "J" on the end. My first theory was that if any of the 4 connector tabs for each spade was bent after being put into service, it happened when inserting the battery due to a misaligned spade or tab. I have attached photos of those chargers with photos of their connectors following them.
It's not clear to me why the first 4 (A-D) DJI spade connectors are raised. The corresponding connector tabs on the batteries don't seem to be any longer in the contact points, if the purpose was to provide more surface area.
Now for the really interesting part and conclusion......So I examined the spades on the DJI connectors and noticed that the edge of the tip on the spades have a very narrow bevelled edge and rounded so as to help the spade find the empty space between the battery's connector tabs when inserting so as not to catch an edge and bend the connector tab. I then inspected the drone's battery compartment spades and found the same thing, very narrow points on the spade front edge. The 3rd from last photo is from the DJI single port wall charger.
Then I inspected the front edges of both the Yx and the FstopLabs connectors. They all were noticeably less beveled at the tips and much wider on the tips, therefore increasing the likelihood that an edge would catch one of the 4 connector tabs and bend it. The last 2 photos are of the Yx and FstopLabs connectors. When compared to the DJI spades they are clearly not as bevelled and rounded at the points.
So, my conclusion is that the aftermarket brand charge connectors are causing the bent connector tabs. I look at all of the other comments above and notice that ALL of them are using DJI chargers and NONE of them are having the issue, which further supports my conclusion.
Remedy? I guess there is one really easy remedy which is to use only DJI original equipment. Doesn't that sound like a typical manufacturer line? lol. I just wish DJI would realize that they need to up their game in the chargers they provide. For people who need to fast charge many batteries simultaneously, which are often professional drone pilots, what they offer doesn't fit the need for price and convenience. That's the only reason why some of us have had to resort to purchasing aftermarket chargers. When the
Mavic 2 Pro came out, to buy 3 separate DJI
Mavic 2 wall chargers would have cost about $300. But the aftermarket 3 port
Mavic 2 simultaneous chargers cost about $50 when first available back in 2019. Pretty easy decision, notwithstanding the bent connector issue.
Also, another remedy idea, you might try using a super-micro file and round and bevel the edges of all of your aftermarket chargers' tiny connector spades, which sounds kind of tedious. But it may help avoiding bent connector tabs on the batteries. I have not tried this yet.
What I find interesting is that the previous Mavic Pro/Platinum line had smaller 3 cell batteries and the same number (10) and size of connector tabs and spades. When DJI upgraded to 4 cell packs for the
Mavic 2 line they kept basically the same connectors despite having slightly higher voltage and amp draw requirements that increased the max speeds by about 5 mph. However, I have seen no evidence that this has created any battery draw or connector issues. I think DJI did a great job designing the battery/onboard battery compartment/battery connectors on all of the Mavics, including the new
Mavic 3. The same is not true, in my opinion, for the
Phantom 4 Pro line as I have read about and experienced several instances of melted battery contact tab housings and melted plastic around the base of the connector spades in the battery compartment. I won't go into that any deeper here, though.
Every few months, I have been careful to clean the
Mavic 2 Pro connectors of oxidation and contaminants, like dirkclod mentioned, and I use DeoxIT D5 in a spray can. I also read that WD-40 and WD-40 Specialist Contact Cleaners work well but have not tried them myself. On the spade contacts in the
Mavic 2 drone battery compartment and on each of the charger's connector spades I use a few drops of DeoxIT D5 on a trimmed down cotton swab and go between the spades and wipe off the residue. For the
Mavic 2 Pro batteries, I use a small piece of paper folded in half or half again, depending on the thickness of paper you use, and put a few drops of DeoxIT on that, and insert it between each of the 10 battery connectors to the point that it "rubs" all 4 contact tabs and when I pull it out it there is clearly visible dark oxidation residue on the paper. With all of the dust and the repeated cycles of inserting and removing the batteries there is definitely oxidation and contamination buildup on these connectors that is not helpful, especially for moments when amp draw is high. To me, it's about as satisfying as flossing your teeth after you have eaten corn on the cob, but I'm a dork like that.
Hope you all found this helpful !
Milo
