Ho everyone,

I have my Mavic Pro for two days now and am very impressed.

In addition to the Mavic I also bought one additional flight battery pack.

After first charging of this additional pack, the third LED was flashing twice per second. OK, as per manual that means overcharging. I hooked it up to the Mavic and checked the battery status. Indeed, one cell had 4,31V and the other two had 4,21V.

My question is: How can this happen? I would expect the "intelligent" flight battery to balance the cells while charging. I have been flighing model airplains for a couple of years now and always charge my lipos with balancers that ensure balance of all chells stays within 0,01V.

Is my new battery pack defect? Should I return it?

Thanks for your time and answers.

You can try discharging it by using it in a low attitude, 5', keep it close to you to make sure it is OK. Then recharge it again. If you still have a difference, you can return it. Batteries have 6 month warranty.

I would send the battery back if one of the cells is .1V out from the others... hopefully you did not purchase the battery from DJI direct because it will probably take you 2 months for replacement, DJI support is rubbish

Please try with dronist's advice and keep us posted.

DJI Mindy Posted at 2017-5-9 00:24
Please try with dronist's advice and keep us posted.

I tried loading and hoovering down to 30-50% three times. No luck. The imbalance and the loading error remained.


I now sent it in via my dealer. Keep you posted.

KloppKopp Posted at 2017-5-16 08:18
I tried loading and hoovering down to 30-50% three times. No luck. The imbalance and the loading error remained.
[view_image]

If you have any further issue, please feel free to let me know.

KloppKopp Posted at 2017-5-16 08:18
I tried loading and hoovering down to 30-50% three times. No luck. The imbalance and the loading error remained.
[view_image]

KloppKopp , Good Catch , you saved yourself from a faulty battery that can cause
                  Your AC to unexpectantly Crash
FlySafe-FlyFree

Bradders Posted at 2017-5-8 11:30
I would send the battery back if one of the cells is .1V out from the others... hopefully you did not purchase the battery from DJI direct because it will probably take you 2 months for replacement, DJI support is rubbish

Hi Bradders, I found some resourceful information for your Future reference:
Voltage drops are normal and typically happen along with higher current (Amp) use. It is normal to see voltage drops when the load of the aircraft increases (Amps), typically seen when climbing up.
The voltage drops (0.02v-0.1v) are normal and are seen on many flights.
lolllll Post #9 wants to add comments go right ahead --- Learn to understand the proper terminology instead of just repeating what I just posted.
Troller you had your Chance , You Lost lolllllll
FlySafe-FlyFree  

SkunkWerxs Posted at 2017-5-17 02:27
Hi Bradders, I found some resourceful information for your Future reference:
Voltage drops are normal and typically happen along with higher current (Amp) use. It is normal to see voltage drops when the load of the aircraft increases (Amps), typically seen when climbing up.
The voltage drops (0.02v-0.1v) are normal and are seen on many flights.

Think the issue was an unbalanced battery / over charged cell, not voltage drops under load. I wouldn't worry about a .1v variation but I'd keep an eye on it and store it somewhere safe.

Voltage will drop throughout the flight, and voltage readings may vary when under load for obvious reasons, so you'll see them drop and rise a little. If I could get back from a flight with only 0.02 - 0.1v drop I would be very happy

Yes , the issue is not about voltage drop during Flight but Voltage differences in charging.

I also am a little bit worried that the cell is charged up to 4,37 V (see pic above). I always thought Lipos should not charge over 4,2V - 4,3V Max. Or are these not LiPos?

KloppKopp Posted at 2017-5-18 03:10
Yes , the issue is not about voltage drop during Flight but Voltage differences in charging.

I also am a little bit worried that the cell is charged up to 4,37 V (see pic above). I always thought Lipos should not charge over 4,2V - 4,3V Max. Or are these not LiPos?

You did not understand I posted the values of  (0.02v-0.1v) to show it is an "Acceptable"
indifference of the battery Cells
Sorry for the misunderstanding

SkunkWerxs Posted at 2017-5-18 03:28
You did not understand I posted the values of  (0.02v-0.1v) to show it is an "Acceptable"
indifference of the battery Cells
Sorry for the misunderstanding

Point made I think, you're trying to teach but need to know the subject a bit better. You're confusing people by talking about in flight voltage drops. Sometimes it's ok to just sit back and listen.

indifference - noun
1.lack of interest, concern, or sympathy.

My batteries always seem indifferent to me

Sorry, but with bait like that who can resist, and you have been trolling my topics all night, so don't get upset if I come here and point out how you are NOT helping!

So here is the update:

Called the German distributor for DJI today where I bought my MP and asked about the status.

They told me that the battery is on the way back to me. They say that they tested it and think the cell drift is no issue and also the 4,37V is no problem because these are "high voltage" batteries. I should not worry and just fly.

@DJI Mindy, Would you agree with that?

Jezus christ is this thread for real? So many red flags here i cant even begin.... An out of balance battery pack that wont balance itself? honestly battery cells i soldered together from broken packs had les balance deviation than this Also wtf @ DJI customer service.

This is all insane. Yes they make cool products, but with an aftermarket service like this (150 euros for a battery that wont even properly balance and then reject any solutions) is a big big big big big no no.

But here's the thing: this is not the only big nono i  have seen your company do in short time. I recently aqcuired a naza v2 flight controller. It lacks settings that even 5 dollar aliexpress FCU have. (like very important basic things like setting RTH height) when asked about it? "please upgrade to a more advanced system for 700 bucks".

Than i recently saw a post of some dude where the tracking malfunctioned and caused the drone to crash into a tree. This was not covered under guarantee. Why? Because the drone had been tipped over a year prior to the malfunction (and was repaired by DJI) and this was the cause of the malfunction.

Sorry DJI but your company has such ...ty aftersales that i cant even begin.... Will never buy your products new. Guarantee and service is a joke anyway.

You can use it, but after a while you get a battery warning and you can't take off. So send it back, it can't repair by discharge. I have one (old) with same thing.