Battery Swelling - beware - near accident today

[WDKZoom]

it would seem that temperature is the biggest issue with battery life up to now my batteries are fine, but in the UK we dont get the extreme heat so maybe that contributes to the lack of swelling ,as far as replacements are concerned ,they are getting thin on the ground ,the MPP ones still seem to be available ,and of course there are aftermarket ones as well i purchased my MPP flymore in 2018 as well just around the time the M2P was released and i also purchased an extra battery so i have 4 as well i have 458 flights 108 hours 442 miles according to airdata on the MPP

Would you be referring to the extreme heat of the day, storage or both? I am in Nevada coming off a summer off a record number of consecutive over 100 degree F days. I have flown only early mornings when the temperature is around 85 degrees and my batteries are stored at 78 degrees. Do you think those conditions would be subject to swelling?

WDK

 

[Lets Fly]

Here in Florida yes we get hot. I have one battery from my Mavic Air that started to bulge after a year and a half.
The only time they get hot is during the flight, then into an air-conditioned car to the AC house and I always let
them cool before charging. I have three newer ones that are fine. Holding them and looking at them sideways
they may appear fine. Place the battery on a flat surface and just tap it If it spins replace it.
Hoping not to see this for a long time with the new M2Z.

 

[old man mavic]

it is clear that any lipo that gets very hot for what ever reason will at some point swell as it gasses off ,this can happen in flight under a hot sun ,during storage in a hot vehicle ,or if stored in excessively hot conditions ,heat is a by product of the way a lipo stores and discharges its charge ,and dont forget the batteries we use in our drones store a lot of charge for their size and are able to discharge at relatively high current rates ,comparing them to devices such as phones or other battery powered devices is really not applicable ,one of the reasons that DJI have tried to put safeguards in place in their battery packs to protect them from miss use is because they are volatile if abused

 

[Pushkur]

Tried out the Velcro strip with shims,I found in a bag or drone bits and pieces,think they belonged to my mavic mini travel kit.
Not perfect,but I felt so much more confident, especially as sun is blazing today.
Dji should be supplying something along these lines ,not leaving it up to there customers, when they know the design is flawed to cope with a battery that can swell without warning.
pic below...and also my cool new black silicon copper yagi’s that are a centre mount,as opposed to the original design.
Need every nite possible flying in bright sunlight with no shade,hence the monitor /Lifthor combo

 

[Ken-Mav-Mtl]

Tried out the Velcro strip with shims,I found in a bag or drone bits and pieces,think they belonged to my mavic mini travel kit.
Not perfect,but I felt so much more confident, especially as sun is blazing today.
Dji should be supplying something along these lines ,not leaving it up to there customers, when they know the design is flawed to cope with a battery that can swell without warning.
pic below...and also my cool new black silicon copper yagi’s that are a centre mount,as opposed to the original design.
Need every nite possible flying in bright sunlight with no shade,hence the monitor /Lifthor combo

Thanks for recognizing this to be a major design flaw. The workaround with Velco is the fail-safe needed to fly with confidence.

 

[DanMan32]

Keep them cool until flight time. In warmer weather, I keep the batteries in a small cooler with an ice pack during transit.

The higher battery temp during/after flight is probably not as much of the problem since you're already probably below 80% before it reaches temps that we'd be otherwise concerned about in storage.

Laptop manufacturers are already setting options that users can use if they tend to keep the battery charged most of the time, where the battery will only be charged to about 80%.

 

[WDKZoom]

Thanks for recognizing this to be a major design flaw. The workaround with Velco is the fail-safe needed to fly with confidence.

I don’t share the design flaw thought. While I am not aware of that many batteries all told that over the time of one flight swell and eject themselves but rather was already slightly swollen or a problem before you put it in. Once is too many of course especially when it causes your drone to fall from the sky, however a Lypo battery has its known faults and under the right conditions will fail just like a prop motor the motor or fan....no strap for those. I choose to check the battery very carefully and place it in the cradle and fly it as was intended without a strap.

WDK

 

[Ken-Mav-Mtl]

I don’t share the design flaw thought. While I am not aware of that many batteries all told that over the time of one flight swell and eject themselves but rather was already slightly swollen or a problem before you put it in. Once is too many of course especially when it causes your drone to fall from the sky, however a Lypo battery has its known faults and under the right conditions will fail just like a prop motor the motor or fan....no strap for those. I choose to check the battery very carefully and place it in the cradle and fly it as was intended without a strap.

WDK

I disagree with you that the Mavic 2 (battery fit to drone) is not flawed by design.

The battery design was changed from Mavic Pro to Mavic 2 to remove the expansion area on the bottom of the battery.

The Mavic 2 batteries sit flush to the frame of the Mavic 2. I assume that they needed to use this extra space on the bottom of the M2 battery to allow for the greater performance needed for the Mav 2.

See the attached photo which compares the Mavic Pro to the Mavic 2 series batteries. The extra space on the bottom of the battery is easy to see.

If they kept the design of the Mavic Pro battery, which has room for expansion on its bottom surface, then the battery would have more room in case of heat build up and its associated expansion within the battery compartment. This in turn would not allow so much pressure to eject the battery from the drone during flight.

If you research the number of cases where battery separation has occurred, I'm guessing that 95% of the reported cases are Mavic 2 series.

 

[WDKZoom]

I disagree with you that the Mavic 2 (battery fit to drone) is not flawed by design.

The battery design was changed from Mavic Pro to Mavic 2 to remove the expansion area on the bottom of the battery.

The Mavic 2 batteries sit flush to the frame of the Mavic 2. I assume that they needed to use this extra space on the bottom of the M2 battery to allow for the greater performance needed for the Mav 2.

See the attached photo which compares the Mavic Pro to the Mavic 2 series batteries. The extra space on the bottom of the battery is easy to see.

If they kept the design of the Mavic Pro battery, which has room for expansion on its bottom surface, then the battery would have more room in case of heat build up and its associated expansion within the battery compartment. This in turn would not allow so much pressure to eject the battery from the drone during flight.

If you research the number of cases where battery separation has occurred, I'm guessing that 95% of the reported cases are Mavic 2 series.

I am no engineer so I am not disputing the design of the battery....I thought you were saying that it should have been designed with a strap. If my battery is at all in question, I am recycling it and buying another rather than tying it to my drone. As to your 95% number of reported cases, that still may be only 1% of all the Mavic 2 series flying. I am not saying that is the case but any manufacturer that can boast of 1% error rate can accept that design flaw all the way to the bank.

WDK

 

[Ken-Mav-Mtl]

I am no engineer so I am not disputing the design of the battery....I thought you were saying that it should have been designed with a strap. If my battery is at all in question, I am recycling it and buying another rather than tying it to my drone. As to your 95% number of reported cases, that still may be only 1% of all the Mavic 2 series flying.

WDK

If I fly my Mavic 2 with a 1% probability of mission failure, then that is a risk that I would not take.

Once you experience a crash that is not related to pilot error, you lose a great deal of confidence in the Mavic 2, unless the risk of failure is far less, such as less than 0.01%.

Aviation requires a very high degree of reliability, which is why redundancy and fail safes are necessary.

A velcro strap does provide a fail safe. Proper design would eliminate the need for such a work around as a velcro strap.

However, you are absolutely right. Flying with a questionable battery that has shown any sign of potential failure would amount to an unacceptable risk.

 

[WDKZoom]

If I fly my Mavic 2 with a 1% probability of mission failure, then that is a risk that I would not take.

Once you experience a crash that is not related to pilot error, you lose a great deal of confidence in the Mavic 2, unless the risk of failure is far less, such as less than 0.01%.

Aviation requires a very high degree of reliability, which is why redundancy and fail safes are necessary.

A velcro strap does provide a fail safe. Proper design would eliminate the need for such a work around as a velcro strap.

However, you are absolutely right. Flying with a questionable battery that has shown any sign of potential failure would amount to an unacceptable risk.

I think your expectations are a little high especially if you would not fly with a 1% or less failure not to mention taking into account all the times you did fly the drone and it landed perfectly. Nothing made by man is perfect which is why most of us get butterflies every time we take off.

WDK

 

[Pushkur]

Just bought this cheap little purpose built item (Ali Express).
Flying in high temps, drone and battery always come home pretty hot, with the fan running in the Smart controller.
All need to cool off ,before adding a fresh battery to fly again.
This is simply peace of mind insurance for a battery swelling during a 20 min flight on days with hot blazing sun.

 

[MikeC]

It is not just a temperature thing. I have 2 of 3 batteries for my M2P swelling and I do not fly in hot temps....because it rarely gets hot. My last flight where the battery almost detached, it was 46F. My problem is trying to get batteries shipped to Alaska, it is hard to find someone that ships these batteries.

 

[skiptv]

I have had three batteries swell in my Mavic Pro 2. Each time the temps were over 90 degrees. 91, being the lowest and 97 being the highest. If the battery swells in-flight it could cause the battery to unseat in the compartment and the drone to drop out of the sky. DJI does not warranty them, but will usually give you a 15% discount for a new one. If you have a pro AirData account you can actually have a record of your battery temp. I also have a Phantom 4 Pro Plus, and have had no issues with batteries with temps in the 90s

 

[MROJAS]

All LiPo's swell with time and use, they simply degrade. Better to discard after noticing any swelling.

 

[ChrisOutdoors]

The primary cause of swelling has to do with # charges you put them through, the temperature playing a low factor in the life of the battery. The research I've done on li-po batteries suggests your battery habbits play a large part in how long they'll last. Do you fly until the batteries are in the single digits, if so that really shortens their life. Do you use a longer discharge time of 10 days or more, that wears them down, or worse, always keep them fully charged. The ideal storing of batteries is in a cool, dry location at 50%. Are you using an aftermarket charger that "miraculously" charges the batteries 10-20 min faster then DJIs? If so, the trade off is heat and battery longevity.

Regardless, at some point li-po batteries will swell.

I've had my MPP since 2017 with 4 new batteries. 1 started swelling around the 180th charge and the 2nd around the 190th charge. I expect the 3rd and 4th will start soon, pushing over 200 charges on all 4 batteries. I'll keep using the swollen ones this winter and likely replace by spring.

Looking at aftermarket batteries now due to the ridiculous
price for new DJI batteries.

I'll be excited for the day we can move away from li-po, swelling in batteries that cost over $100 after a few hundred charges seems ridiculous.

 

[Pushkur]

It is not just a temperature thing. I have 2 of 3 batteries for my M2P swelling and I do not fly in hot temps....because it rarely gets hot. My last flight where the battery almost detached, it was 46F. My problem is trying to get batteries shipped to Alaska, it is hard to find someone that ships these batteries.

Try Ali express,...you can read reviews for the battery’s

 

[tiwag]

Tried out the Velcro strip with shims,I found in a bag or drone bits and pieces,think they belonged to my mavic mini travel kit.
Not perfect,but I felt so much more confident, especially as sun is blazing today.
Dji should be supplying something along these lines ,not leaving it up to there customers, when they know the design is flawed to cope with a battery that can swell without warning.
pic below...and also my cool new black silicon copper yagi’s that are a centre mount,as opposed to the original design.
Need every nite possible flying in bright sunlight with no shade,hence the monitor /Lifthor combo

Monster combo ! ?

 

[tvdwouw]

One more tip to prevent swelling: never store them charged! Most people charge them directly after a flight session.
Normally I end with about 20% rest charge. I leave them like that until I know I will fly again, then charge them in the morning with a timer. If not flying for a long time, check batteries every 2 months or so and charge them until the second LED starts flashing.
BTW, DJI just changed the default time for automatic discharge for M2 P/Z to 2 days!

 

[DanMan32]

The primary cause of swelling has to do with # charges you put them through, the temperature playing a low factor in the life of the battery. The research I've done on li-po batteries suggests your battery habbits play a large part in how long they'll last. Do you fly until the batteries are in the single digits, if so that really shortens their life. Do you use a longer discharge time of 10 days or more, that wears them down, or worse, always keep them fully charged. The ideal storing of batteries is in a cool, dry location at 50%. Are you using an aftermarket charger that "miraculously" charges the batteries 10-20 min faster then DJIs? If so, the trade off is heat and battery longevity.

Regardless, at some point li-po batteries will swell.

I've had my MPP since 2017 with 4 new batteries. 1 started swelling around the 180th charge and the 2nd around the 190th charge. I expect the 3rd and 4th will start soon, pushing over 200 charges on all 4 batteries. I'll keep using the swollen ones this winter and likely replace by spring.

Looking at aftermarket batteries now due to the ridiculous
price for new DJI batteries.

I'll be excited for the day we can move away from li-po, swelling in batteries that cost over $100 after a few hundred charges seems ridiculous.

That's just not true. Three of my batteries experienced swelling and I have less than 50 cycles on them. However I did tend to leave them in the car too long, fully charged. The swelling showed up late summer after almost a year of ownership. The majority of swelling occurred during summer.

Laptops are now offering settings to charge only to 80%. They recommend this setting if the laptop is plugged in most of the time where the battery would otherwise be at 100% most of the time.