Battery died in the air...

[hiflyer201]

After an Air 1 battery failure in flight, I went back over the history of that battery with Airdata information, and I really don't think I could have seen it coming. The battery is not swollen, charges normally and all the cells show normal. I have flown it several times after that incident at low altitudes in my back yard as a test. It fails every time in very short order because of a low cell.

 

[snowghost]

After an Air 1 battery failure in flight, I went back over the history of that battery with Airdata information, and I really don't think I could have seen it coming. The battery is not swollen, charges normally and all the cells show normal. I have flown it several times after that incident at low altitudes in my back yard as a test. It fails every time in very short order because of a low cell.

How many charges on it? I read somewhere on the forums that DJI batteries are rated for 200 cycles.

 

[hiflyer201]

How many charges on it? I

I could check, I think it was about 130. The other two batteries that I received with the original purchase died of advanced swelling and my fear to use them. I purchased one new battery and I have been very careful not leave it in my car and to cool it completely before charging. I'm hoping it lasts.

 

[Gimbal2019]

I understand that Dji Mavic Air 1 batteries self discharge and the lights change from 4 illuminated to one on steady and a second light flashing. Other pilots have recommended to recharge the batteries before flying if the batteries go unused for a few days(before self discharge feature takes effect). I have found my charger will not top up my batteries if the battery shows 4 lights. My self discharge feature starts after 10 days of no flying so if I want to go fly on day 9 the charger will not top up the battery if 4 lights show.
My question is how do those pilots recharge their batteries if they have been idle for awhile but not long enough to start self discharging?
I don't think I have noticed any difference between a freshly charged battery and one that has been sitting for 8-9 days.
Here's wishing you all a VERY MERRY CHRISTMAS!! - with lots of flight time - LOL

 

[Kilrah]

My question is how do those pilots recharge their batteries if they have been idle for awhile but not long enough to start self discharging?

No, as you can see you can't since they're already full.
It's if they self discharged already that you want to recharge them.

 

[davidk_ro]

Hi. BMS judgeb he state of charge based on:
Peak voltage on each cell while charging
Coulomb counter: how many amp-hour goes in and out the battery while charging/discharging

But when the battery is old some cells develop increased internal resistance. While flying, because of this, the battery voltage (or a cell voltage) may appear lower. If this internal resistange is too high the voltage may go unacceptably low and BMS thinks the battery is depleted.

 

[tribar]

DJI Smart Battery - How It Works & Best Practices - Mavic & All Models Everything You Need To Know:​

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[mikegrad]

DJI Smart Battery - How It Works & Best Practices - Mavic & All Models Everything You Need To Know:​

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good info in this video, thanks for posting.

 

[tribar]

Single cells for DIY repair are available here:

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[DavidBlezard]

Yes I'm familiar with the "self discharge". My question is about the indicator lights on the top of the battery. Don't the lights on the top of the battery show if the battery is fully charged? If all 4 lights are on, can the battery still be at 40%???

I’m sure it is possible, my batteries always show 2 solid and the 3rd flashing after they have been sitting around. Also, unless you are flying in the next day or 2, don’t put your batteries on the charger when you back home. It just wastes cycles.

 

[sequel]

To give information about the use of drone battery. How should we store the battery? What should be considered about the charger? How to turn on the battery that is not charging? The aim is to give general information about the drone. Unfortunately, YouTube translate doesn't work very well. with translation. There are not many people in our country who know these things. I took the video to inform.

Closing Cells / Not Opening Cells / Non-Charging Cells, How To Repair

 

[mlaney]

My Mavic Air just ran into the same issue, sadly crashed, gimble smashed and some broken propellers. 4 lights recently changed, made it a flight time of 1:30 before voltage alerts all over the place, immediately headed home and dropped like a rock, end of flight battery still showed 80+%. The other battery I had, had swollen and deformed that it would no longer fit safely in the Drone. I know these things happen but it really makes ya think about your next purchase if your 800+ $$ drone cant make it 2.5-3 years with limited use. Cant find the old batteries for any reasonable price, so just kept using the remaining one, was only get 10 minutes of flight time at best near the end

 

[argp74]

I had the same problem and almost near to loose the drone into the sea (MAir1). 2 of the 3 batteries died the same day. After that i search more about to find out what happened and i realise that you have always check the batteries before you fly away. The post from "JoeIP" describes the procedure very well. Also use "AIrdata" app to analyse flying data.
So i tried to find new batteries but everywhere was out of stock. I was contacted with DJI Europe Support and the send me new batteries at 79€ each one.
If you looking for batteries contact DJI Support.

 

[EpicFlight]

The actual charge of the battery can be up to 40% less than the displayed charge. All Lipo batteries are best kept at near 50% charge, so DJI built in a feature called “self discharge” that will begin self discharging the battery after a preset amount of time after being plugged in or flown. You can adjust this amount of time in the DJI GO app. The best way to ensure you have a full battery is to charge it and fly within 2 days of that charge.

I must dispute this in the strongest terms. For two reasons:

• My batteries, 5 years old now, do not and have never behaved like this. When they self-discharge the state of charge is accurately shown on the battery lights.
• I'm an EE, and have designed lipo packs, the BMS, etc. Simply put, the state of charge correlates with the unloaded voltage level. A lipo can not be 60% (or 20%) depleted and present 4.15–4.2V. It would sit around 3.7–3.8V. That's physics.

I've never, ever seen a DJI battery behave as described by @Flippigan, across P3, M1P, M2P, Spark, Mini 2, MA1, A2, A2S, and FPV. Never. 3 or more batteries on each of those.

To wit, I just pulled out my MA1 after 3 years in the closet. All 3 batteries were showing 2 1/2 lights (2 solid, one blinking, 60% charge). Charged all three in parallel on my Yx charger (after 15 frustrating minutes finding it), and they charged normally, as expected.

 

[EpicFlight]

The LEDs display the estimated charge based on capacity and many other factors. But if capacity has dropped significantly since the last full cycle it can be off, and if the capacity is there but the cells' internal resistance has degraded enough to cause a large voltage drop then it will also cause percentage to drop like a rock.

This is correct.

However, it is very unlikely that an MA1 battery young in its cycle life (guessing less than ~50 cycles, rough guess, would have to know the specific cell model/mfg/chemistry), it will store very well.

Cycling reduces capacity, not storage. Keep in mind an old pack with reduced physical capacity as measured against rated capacity is still at 100% full charge, and capacity, when all 4 lights come on, even though it no longer meets rated capacity.

 

[Kilrah]

To wit, I just pulled out my MA1 after 3 years in the closet. All 3 batteries were showing 2 1/2 lights (2 solid, one blinking, 60% charge). Charged all three in parallel on my Yx charger (after 15 frustrating minutes finding it), and they charged normally, as expected.

You WILL want to be very careful when flying them though, that's the whole point. On this particular model the batteries do tend to go bad with time regardless, even if in theory proper storage doesn't have that much impact and it's not the case with other models' batteries, with the MA1 there have been a lot more reports like this one than usual.

It's just an observation of what's happened, how it's supposed to behave is pretty much irrelevant...

Also did you try to power up the aircraft before charging? On my friend's MA1 that was also stored for quite a while of the 3 batteries one was dead, on the other 2 there were 2 1/2 lights as well, but putting them in the aircraft and powering up they went down to critical single-blinking LED in a few seconds before shutting down, i.e. the meter can't be trusted after long storage.

 

[EpicFlight]

You WILL want to be very careful when flying them though, that's the whole point.

Oh, of course! After all, 3 years...

I'm back, flew all three batteries VLOS in a baseball field, didn't go over 30' or so. Did some gesture stuff, followed me around a bit, flew some corkscrews up, down, practiced coordinated snap turns at full speed sport, and some other playing around.

Delighted to say there were no problems. Got 20 min on the first, 25 on the second, then I confess I quit after 8 min on the third out of boredom. I'll have to do the same shakedown with that last one another time.

One unexpected frustration, powered up and hovered in my living room, but forced a flysafe DB update at the field before it would let me take off. Had to borrow my wife's phone to do it, mine won't run GO4.