Warning: P3 Battery LEDs Can Be Deceptive

[Phantom751874]

Got a good deal on P3 batteries probably almost 2 yrs ago. Stocked up and had been maintaining them at 50% charge since then. They were stored not in use but maintained.

Anyway decided to but them in a P3 so I could look at cycles from the GO app. Low and behold even though they indicated 2 bars they were drained completely. They wouldn’t power up the P3 and afterwards their LEDs indicated as much. LEds lied.

I started charging them too 100% but had 3 that would not start a charge. 2 single blinking 1st LED and that’s it. Would not go further. One wouldn‘t do anything besides blink when the button was pressed then would turn off.

Ultimately was able to get one to to charge and I marked that battery so I can monitor it. Still working on the other 2 to see if they are salvageable. It’s a shame these were all brand new genuine DJI batteries.

Moral of the story. DO NOT trust the LEDs if you’re storing batteries. Put them on a charger to check instead.

 

[LarBear360]

Got a good deal on P3 batteries probably almost 2 yrs ago. Stocked up and had been maintaining them at 50% charge since then. They were stored not in use but maintained.

Anyway decided to but them in a P3 so I could look at cycles from the GO app. Low and behold even though they indicated 2 bars they were drained completely. They wouldn’t power up the P3 and afterwards their LEDs indicated as much. LEds lied.

I started charging them too 100% but had 3 that would not start a charge. 2 single blinking 1st LED and that’s it. Would not go further. One wouldn‘t do anything besides blink when the button was pressed then would turn off.

Ultimately was able to get one to to charge and I marked that battery so I can monitor it. Still working on the other 2 to see if they are salvageable. It’s a shame these were all brand new genuine DJI batteries.

Moral of the story. DO NOT trust the LEDs if you’re storing batteries. Put them on a charger to check instead.

Good point. I purchased several a couple of years ago at a low price from Target. On the advice of some other more experienced pilots I placed them into rotation with my older batteries rather than place them in storage.

 

[solentlife]

I have been banging on about this for ages ...

The LED's are only a rough guide and solid lit is 25% increment. Flashing LED is 12.5% ... and so on.

The best way to maintain Lipo's is to charge up and then back to storage at regular intervals. With DJI - we are spoilt because of the auto-storage function of the battery smart board.
So - charge up full (forget all that bit of 50% etc .... ) ... then let the auto system take care of it. Every month or so repeat.

That way you will have your batterys healthy for a long time for no cost to cycle life literally.

 

[mike g]

good info thanks

 

[MTW4518]

I found this to be true as well. They show their true charge level when attached to the battery charger

 

[gppms]

Got a good deal on P3 batteries probably almost 2 yrs ago. Stocked up and had been maintaining them at 50% charge since then. They were stored not in use but maintained.

Anyway decided to but them in a P3 so I could look at cycles from the GO app. Low and behold even though they indicated 2 bars they were drained completely. They wouldn’t power up the P3 and afterwards their LEDs indicated as much. LEds lied.

I started charging them too 100% but had 3 that would not start a charge. 2 single blinking 1st LED and that’s it. Would not go further. One wouldn‘t do anything besides blink when the button was pressed then would turn off.

Ultimately was able to get one to to charge and I marked that battery so I can monitor it. Still working on the other 2 to see if they are salvageable. It’s a shame these were all brand new genuine DJI batteries.

Moral of the story. DO NOT trust the LEDs if you’re storing batteries. Put them on a charger to check instead.

The same happened to me with the p4p and mavic pro batteries also.

 

[Tunnelsen]

Very useful. Thanks!

 

[Phantom751874]

So 2 of the 3 batteries I was able to salvage. Learned how by looking at info here in these forums.

Basically if you have a single blinking light that stays blinking after you turn on the battery, in other words stays on, then you can usually recover but it can take many attempts.

Leave the battery alone and off for 5 minutes.

Turn on the battery then leave it alone for another 5 minutes.

The battery should stay on and blinking. Then hook up the charger and leave it alone. The battery should stay on and blinking. Leave it alone for a at least a few hours.

If it doesn’t start making progress charging (increasing LEDs) after a few hours repeat the process again.

It can take 5 or more tries before you see charging progress. In my experience if the battery stays on then it should eventually start charging as long as you keep repeating the process.

1 of my batteries would not stay on. I left it on the charger anyway for 12+ hours multiple times without success.

I cracked that battery open and the cell voltages were all over the place with a couple cells being below 2.5 volts.

I manually charged the battery directly with a hobby charger (bypassing the battery management board). This didn’t make a difference. The BMS is bricked. Lost cause.

Now, the 2 batteries I was able to revive are still suspect. Each if them have 1 cell that is out of balance from the others by 0.07 to 0.08 volts. This isn’t ideal. I haven’t tried directly charging the lower cell as opening the batteries up can be destructive to the case. I can always use them as general use battery bank chargers. I doubt I will fly them again.