Bloated Mavic Air Batteries - Replacing and Fixing

This message discusses two main aspects of the batteries for the Mavic Air:

  1. Replacement by DJI
  2. Repair

Background
All three of my Mavic Air batteries supplied in the FlyMore kit in March 2019 had suffered the classic swelling commonly reported all over:


The one on the left has managed to pop the casing off, and the other two have significantly swollen bellies.

Although they can fly for 14-18 mins, they could only just about fit into the battery compartment. The standard advice, here and everywhere else, is not to use them in this condition - there is significant risk to both the aircraft and the public (since they can pop out of their plastic locks).

Whilst this risk can be mitigated with sufficient strapping, the general consensus is to replace the batteries. These seem to be hard to acquire in the UK, with many suppliers showing no stock, and those with stock being of dubious virtue (eBay, “Drones Planet UK”) , and highly priced - for example, £124 each.

Replacement

In a posting (that I have not been able to find) on this site, (or possibly on MavicPilots), someone discussed the fact that DJI had replaced their Mavic Air batteries after the 12 month warranty. The poster said it was a consumer law issue, and the batteries were not of merchantable quality.

I thought it was worth trying this method. I went on the DJI website, explained that the batteries were beyond the 12 month warranty, and DJI asked me to send pictures and serial numbers. After a few days I got an email from DJI Support with their conclusion: the batteries are out of warranty. Since I had stated that from the outset, I wasn’t too surprised…

However, I’m a persistent person, and looked up UK consumer law on the interweb. It’s relatively unspecific, but does imply some responsibility for quality and durability in proportion to price. It also implied that you have to do everything you can to seek redress with the company before even thinking about legal measures.

So I wrote back to DJI to check on how long they considered was the reasonable lifespan for their batteries. They wrote to ask me to specify the “UK Consumer Law” that I was referring to, which I did, and then wrote back to say that since the batteries were more than 24 months old, they would not replace them.

I replied to this email, asking them to confirm that they did not expect their batteries to last longer than 24 months.

This latter resulted in DJI agreeing to replace the batteries. They came fairly quickly and in consumer retail boxes:

They look and feel brand new, with fresh DJI stickers on them, and have a marking:
image
“IN TW RU”, perhaps implying Indonesian or Indian, Russian and Taiwan markets?
Also, they appear to be fairly new - produced in March 2021?:
image

So: some kudos to DJI for replacing them after 30 months, but perhaps they could admit to a production error since this problem is so widespread?

Repair

With the confidence of having three new batteries, I looked again into how I could fix the bloated ones. Even in their dangerous state, they keep the Mavic Air flying, and AirData estimates their Efficiency at 16-18 minutes:
image

Airdata suggests they are not too damaged:
Screenshot 2021-08-27 at 17.32.40

Also, what ever “Life” is, this battery has a fair amount left:
image

If it wasn’t for their swelling (and the consequent risk), I would have been satisfied by their longevity.

I consulted YouTube and got a mixture of opinions on fixing methods:
• “nothing works” (Puffed and swollen DJI mavic pro batteries opened up to reduce swelling. DO NOT DO THIS YOURSELF! - YouTube)
• “this works, but requires cutting tools” (DJI MAVIC AIR BLOATED BATTERY WORKAROUND - YouTube)
• “this just works” (EASY WAY TO FIX YOUR BLOATED BATTERY AT HOME ( MAVIC AIR DRONE) - YouTube)

So I decided to try the latter, with nothing to lose (battery-wise). The method given in the video required just two bits of kit (a small screwdriver and a pin) and simple method (prise open case then pierce battery pack). I decided to add a face mask, gloves and protective goggles to the required kit, and ensured the battery was not fully charged. I also did the job outside, (and still had fewer ants involved than the guy in the video).

It really was a very quick procedure: my battery was very keen to open, and the pin prick was even smaller than the one in the video. I didn’t have to squeeze it as much as the video showed. Nothing visible exited the battery at the rear end, and I could find no residues on the battery case, gloves or face mask. No noxious smells. I didn’t go green and explode either.

The initial result was impressive:
image
It “feels” flat, is not spongy in any way, and sits on the table as a perfectly flat object, rather than an object that rolls. It also charged back up to 100%.

I have used it three times in the last two weeks, and noticed:
• it fits nicely (and safely) in the battery compartment - no squeezing or hoping for the battery to lock, and no strap required
• no decrease in flight time

Conclusion
I’m feeling much happier about flying and my DJI purchase than I did two weeks ago. A large part of this was the battery replacement by DJI.

However, for those who have exhausted the DJI route, or who are not able to pursue them, there is the repair to consider… Whether this is a long-term fix for the issue, I cannot say - two weeks isn’t enough. But if you were thinking of abandoning your aircraft and batteries due the safety issues around otherwise powerful and effective batteries, this is perhaps worth trying if you observe all safety precautions?

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@Steviegeek :open_mouth: :open_mouth: :open_mouth:

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What a fantastically detailed post @facherty

Thanks for taking the time to type all that up, with pictures, and sharing :clap:t2: :bowing_man:t2:

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Okay - Here come’s the Devil’s Advocate. You’re flying your drone with any of these batteries after you have ‘fixed’ them - it develops a problem in flight - it careers to the ground causing some considerable damage to either property or an individual. How’s your Public Liability Insururer going to deal with this - and how do you think the appropriate authorities should deal with you?

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I applaud your persistence in securing replacements and I’m sure the first part of this post will be of interest and assistence to many :wink:

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No different to the guy who doesn’t have his car serviced by a main dealer, or tinkers with it himself I’d wager

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Is it just me? Or is this iffy. Popping a puffy lipo with a pin? I throw a brick on it to finish the job.

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LiPo batteries are sealed for a reason - like any lithium based battery, if moisture gets in they tend to combust rather fiercely

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Worth a read about venting of a LiPo :scream:

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:notes:
Puffed the ageing LIPO lived in a drone
And frolicked in an FRZ at an airport near my home!
:notes:

Eat your hearts out Peter, Paul & Mary! :+1:

Nah they’re fine just like this :grimacing:

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I couldn’t agree more with this sentiment…
Basically you are flying an incendiary device, a mini V1 albeit with some control up to the point it expires…
I commend the persistence in getting replacement batteries but be bloody grateful and surrender the blown items before shit goes wrong

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Great job getting the replacements. I’d advise not using the repaired batteries. May kill the drone and all that effort for the replacements would’ve been a waste.

@PingSpike: Thanks for the kind words.

@Greyseal2021, @notveryprettyboy, @Sparkyws, @SirGunner, @AHCL and @TassyWass: thanks for re-emphasising the point in my original post - “standard advice, here and everywhere else, is not to use them”, “dangerous state”, “significant risk”, etc. If that was not clear from my posting, my apologies. I will use only my brand new batteries for flying, and it is a rare day when I use three, let alone require six of them!

I am also aware that there are many people with bloated batteries who have been unsuccessful in securing replacements from DJI, and do not choose to secure new ones (presumably on finance/availability grounds). Some of these people (from evidence on YouTube and drone websites) are attempting battery modifications. Informing them that, for me, the procedure was safe and the outcome was positive, at the same time providing the warnings, seems a responsible thing to do. I also tried to supplement the safety guidance (outdoors, mask, gloves). (I would want to reassure @MartG1960 that I did reseal the battery using the toughest tape I have.)

One last point: after four more days with the battery, it:
• still charges fully
• flies for as long as I can stand the noise in my back garden
• does not get excessively warm
• has retained its slimmer shape
This proves nothing; it is just data for our community to balance with other other data.

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If you would like video footage of why you should get rid of puffy LiPos asap the young lads at my flying site just love smashing old LiPos and they explode akin to a hand grenade at worst and piss out probably very toxic smoke at best. Please dont puncture them to “flatten” them, lithium reacts pretty violently with water any sort of moisture getting in there is gonna end badly.

This is what happens when water enters a lipo

Pinched from another post but it does fit in this post too

https://greyarro.ws/t/gator-eats-a-drone-smoking/36130?u=speatuk

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This video should make you feel better I hope.

SAY WHAT!!! Your posting was as clear as you meant it to be. Now you’re inferring… ‘Oh… I wouldn’t personally play with fire - but here’s a box of matches and a flamethrower I just happened to bring with me’. For myself, having dealt with many EU bureaucrats over the years, I prefer it when folk say exactly what it is they mean. I find your reply a poor attempt at a rebuke for you being a bit of a ‘Rodney’ on this topic which you initiated. :wink:

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