Mavic Battery Question - need help!

[Jet Peddler]

I chose to post this here as opposed to the Mavic 2 Pro area hoping to get answers a little faster. Apologies. Also, searched and couldn't find the answer I need...

In late 2019 I bought a new Mavic 2 Pro Combo along with the Fly More kit. Thought I'd use it, but Covid and life got in the way so left it in the box. 18 months ago I opened everything up for the first time and charged all three batteries - all good. Then I had to move, so put everything away again. Never used the drone or put a battery in the drone.

Two days ago I finally get everything out (found a friend who wants to fly drones together) and attempted to charge all three batteries. One charged up just fine, the other two - nothing. The circular light on the charged battery lights up and all appears well. The other two batteries have been on the charger over 12 hours now and nothing still. No segments of the circle lighting up. I've swapped the batteries around to different charging docks on the charger and still no luck. Charger and outlet are working as it already charged one battery.

I've called DJI and as the batteries are 4+ years old, they offer no help. These two batteries each have one cycle on them. Is it typical for them to die with age like this without being used (except for the one successful charge 18 month ago)?

Any suggested fixes or is it possible they may actually be charged and the indicator just isn't working? Or should I just punt and buy replacement batteries? I do see some good deals on refurbs on Amazon that rate 4.7 stars.

Thanks in advance for any help you can give me!

 

[Droning on and on...]

Sorry, you're SOL. They likely self-discharged below 3V enought that the BMS considers the cells damaged.

I would too. Toss them.

It's not guaranteed this will happen in your scenario, but it's not unusual either. There are some hacks people have discovered to revive M2P dead batteries, search the forum. However, I wouldn't recommend it.

The M2P is worth its weight in gold, being the last flagship consumer model that had a fully functional SDK... this means all the third party apps like Litchi work with it. As such, it's not worth losing it to sudden battery failure in flight.

 

[Cafguy]

There are some things you could try BUT honestly Get new ones -You have unfortunately killed your batteries by improper storage SORRY the Best advice I would give you is buy some new or refurbished batteries on Ebay and Take care of them ( like you would a pet ) you can get used batteries with very few cycles gone thru on Ebay dirt cheap
Also I wouldn't try to revive or even Charge those batteries any longer!

 

[slup]

...Is it typical for them to die with age like this without being used (except for the one successful charge 18 month ago)?

Yep... very much typical.

Batteries have active chemicals inside... they aren't like a "dead" screwdriver you can toss in a drawer for years & then pick it up as brand new, fully functional.

When you unpack them, brand new they are half full... there the chemicals are the least active & they can be stored for a very long time (not quite years though). But having them fully charged or depleted & forget them for years will for sure kill them. And don't try to revive them... even if you should get them to take charge, they have very likely sustained permanent damage & can't be trusted in a drone anymore.

 

[zeusfl]

Check this video.

 

[slup]

Check this video...

LiPo cells down to just a couple milli volts is possible to get up to nominal voltage... if you're lucky & it doesn't catch fire. But should you? The battery is severely damaged with both a very high internal resistance & lithium plating on the anode that risk to short out the battery... nothing you do will revert this damage.

It's much better to follow your tag line... & buy new ones.

 

[zeusfl]

LiPo cells down to just a couple milli volts is possible to get up to nominal voltage... if you're lucky & it doesn't catch fire. But should you? The battery is severely damaged with both a very high internal resistance & lithium plating on the anode that risk to short out the battery... nothing you do will revert this damage.

It's much better to follow your tag line... View attachment 172148& buy new ones.

And this is the reason needs to be charge very slowly. As I mentioned if the lipo is very close to the edge of the BMS detection will have a chance. I have recovered safely this many times in the past. If you use a good smart charger they have recovery mode. If you do not feel comfortable just do not don’t even try and if do so make sure do it outside inside a lipo safe charging bag.

 

[Cafguy]

If you do not feel comfortable just do not don’t even try and if do so make sure do it outside inside a lipo safe charging bag.

VERY Sound Advice DON'T Feed the house fire gods.

 

[slup]

... I have recovered safely this many times in the past.

The main question is... what do you think you've recovered?

Recovered from the BMS block, yes... recovered from the cell damage, no way, that's permanent.

And the amount of damage is of course not black or white, it's gradual & not even linear, the damage gets worse the lower the cell falls voltage wise. In the end you can't be sure how a big risk it will be to use that battery in something that relies on it to stay airborne.

 

[zeusfl]

The main question is... what do you think you've recovered?

Recovered from the BMS block, yes... recovered from the cell damage, no way, that's permanent.

And the amount of damage is of course not black or white, it's gradual & not even linear, the damage gets worse the lower the cell falls voltage wise. In the end you can't be sure how a big risk it will be to use that battery in something that relies on it to stay airborne.

This batteries are not use to fly. These batteries are the one I use for play with drone settings or flying next to me, hovering and stuff like that. I check the IR of the battery and if is too high obviously is not good. Just use your common sense. I will not do this in my Mavic 3. This is more on cheap drones.

 

[slup]

This batteries are not use to fly...

That's good to hear

But just so you know... the increased internal resistance isn't the worst, the most serious damage is that lithium metal have plated out on the anode. This causes dendritic structures to form, which can puncture the separator, causing an internal short-circuit.

 

[Droning on and on...]

And this is the reason needs to be charge very slowly. As I mentioned if the lipo is very close to the edge of the BMS detection will have a chance. I have recovered safely this many times in the past.

I would say lucky, not safely.

 

[R_K]

I was able to recover one of my mavic pro batteries that went into hybernation mode. However, I have another issue with this battery. Although it is charged to a required 4.35V per cell when I put it onto a drone, the dji go 4 app shows how fast it drains back to 0% (like within 10-15 minutes). However, the voltage on each cell is still around 4.25V (both on the app screen and if measured by a multimeter). What is wrong with this battery? Is it the BMS board behaving this way? Because the cells accept the charge from a charger without a problem. My guess is that BMS is not computing the voltage the right way. Is there a way to reprogram it so it knows that 3.7V is 0% and 4.35V is 100%? By the way, I have tried to drain the battery down to 3.7V per cell and charge it back to 4.35V to calibrate it, but now 3 days later, it is still behaving strange. Any advice will be appreciated.

 

[Droning on and on...]

I was able to recover one of my mavic pro batteries that went into hybernation mode. However, I have another issue with this battery. Although it is charged to a required 4.35V per cell when I put it onto a drone, the dji go 4 app shows how fast it drains back to 0% (like within 10-15 minutes). However, the voltage on each cell is still around 4.25V (both on the app screen and if measured by a multimeter). What is wrong with this battery?

the lipo cells are damaged internally and the resistance has gotten high enough that the voltage drops under load so it "looks" depleted, even though there's stored charge. As soon as it's not under load the voltage goes back up.

This pack will never work properly again, and it is much riskier to charge it (explosion, fire) than when it was undamaged.

Discard it.