One of my 3 batteries is full (4 green LEDs) and provides the drone with energy, I hear the start melody, I see the picture from the camera on my mobile phone, I can zoom and move the camera - but all 4 LEDs of the drone are red and the remote control gets no information about the battery status. It thinks the battery is empty and it is not possible to start flying. What is wrong? The 2 other batteries are working as usual.

Hi, Paul Lenz. Are you getting any error messages from your screen?

DJI Tony Posted at 7-16 21:51
Hi, Paul Lenz. Are you getting any error messages from your screen?

Not really. When a connection between the drone and the remote control is established, there is a message in red letters "battery is nearly empty, fly home ASAP" or similar. But the battery level is not "0%", it is "--". I also can not get information about the number of charges or the voltage of every cell.

Paul Lenz Posted at 7-16 21:57
Not really. When a connection between the drone and the remote control is established, there is a message in red letters "battery is nearly empty, fly home ASAP" or similar. But the battery level is not "0%", it is "--". I also can not get information about the number of charges or the voltage of every cell.

Are your devices on the latest firmware? Please try to refresh or upgrade it using the DJI Assistant 2. You can download it from here. Can you also submit a screenshot of what you're seeing on your end so I can submit it to our designated team if ever we need to?

DJI Tony Posted at 7-16 22:24
Are your devices on the latest firmware? Please try to refresh or upgrade it using the DJI Assistant 2. You can download it from here. Can you also submit a screenshot of what you're seeing on your end so I can submit it to our designated team if ever we need to?

Everything is latest firmware. Today there was an update, but only regarding flight zones.

Paul Lenz Posted at 7-16 23:24
Everything is latest firmware. Today there was an update, but only regarding flight zones.

[view_image]

Thank you very much. I will get this referred to our designated team. I will get back to you fast. I appreciate your patience by the way.

If needed use a magnifying glass and check that the contacts on the battery are are clean and clear of fluff etc..

Paul Lenz Posted at 7-16 23:24
Everything is latest firmware. Today there was an update, but only regarding flight zones.

[view_image]

Thank you for waiting. We recommend wiping the metal contact pins on the battery (as also advised by Sean-bumble-bee) with alcohol (concentration >= 75%) and retrying. Turn on the battery and leave it for a while to discharge, then charge it again to test. If the above steps do not work, it may be due to the battery cell error, we suggest using another battery. Can you also DM me the serial number of the drone for further checking? Thank you.

DJI Tony Posted at 7-17 00:36
Thank you for waiting. We recommend wiping the metal contact pins on the battery (as also advised by Sean-bumble-bee) with alcohol (concentration >= 75%) and retrying. Turn on the battery and leave it for a while to discharge, then charge it again to test. If the above steps do not work, it may be due to the battery cell error, we suggest using another battery. Can you also DM me the serial number of the drone for further checking? Thank you.

OK, I tried to clean the contacts, but without result as expected.
Sure, I have to use another battery, that's quite logical. But do you really think that I have to throw this expensive and actually well working battery away?
I write you the SN in a Personal Message.

Paul Lenz Posted at 7-17 01:55
OK, I tried to clean the contacts, but without result as expected.
Sure, I have to use another battery, that's quite logical. But do you really think that I have to throw this expensive and actually well working battery away?
I write you the SN in a Personal Message.

Sorry, Paul. I completely understand you. It's not that easy to throw away an item that is valuable but seems like the troubleshooting was already done and it did not fix it. There's a high probability that it's a battery cell error and it can't be repaired. Hopefully, you get some advice from your co-pilots. Thank you for your understanding and support. Have a great day ahead.

A few other suggestions,
1) do you have the USB adapter that allows the battery to be used as a power source for USB? If so what happens if you connect that to the battery switch the battery on and try to charge something with it?
2) post a good photograph of the entire connector on the wonky battery, showing all the contacts and the dividers between them.
3) if you have a multimeter that has very fine probes, check what voltages etc. are seen between the various pairs of contacts in that connector. BUT YOU WOULD NEED TO GOOGLE THIS, both in relation to which pairs of terminals/contact you should test and, what results you should see. That might be a question for a more technically orientated forum than this one e.g. Git hub or something like that, I doubt the Mods here would be allowed to release such information. I have seen pinouts for the connector, in fact I think the car charger shows a pin out but I do not know what you should see. Some of the connections presumably transfer data rather than simple voltages and power.

Sean-bumble-bee Posted at 7-17 03:19
A few other suggestions,
1) do you have the USB adapter that allows the battery to be used as a power source for USB? If so what happens if you connect that to the battery switch the battery on and try to charge something with it?
2) post a good photograph of the entire connector on the wonky battery, showing all the contacts and the dividers between them.

I don't have that adapter, but I am absolutely sure it would work. The battery provides the drone with power, I hear the start melody, I see the picture from the camera on my screen, and I can even zoom and move the camera. I can do everything except take off.
That's why I doubt that there is a cell error.
I hope this photo shows what you want to see. The left 4 pins are (+), the right 4 pins are (-). The 2 pins in the middle seem to transport data.

There seems to be much to learn. The pins in the middle are SDA and SCL for communication.

DJI Tony Posted at 7-17 02:43
There's a high probability that it's a battery cell error and it can't be repaired.

Hi Tony,
I succeeded to check the pins in the middle with an oscilloscope. I found out that there is a bunch of pulses every second if I use a working battery. But there are no pulses if I use the battery I am talking about. That means, all battery cells are OK, but a chip for communication is out of order. And I am afraid, this can not be repaired

Paul Lenz Posted at 7-17 12:50
Hi Tony,
I succeeded to check the pins in the middle with an oscilloscope. I found out that there is a bunch of pulses every second if I use a working battery. But there are no pulses if I use the battery I am talking about. That means, all battery cells are OK, but a chip for communication is out of order. And I am afraid, this can not be repaired

It's good that you found out what should be there but a pity it's not working.
Might it be worth opening the case and having a look at the solder joints etc.. for the signal wires.

The dodgy bit is you'd need to work with the board 'live', if you disconnect the main power I think the ''gas gauge'' or something like that, switches to open circuit and that is effectively the end of the battery unless you can reset the 'whatever'.
It might be better to discharge the battery somewhat if you attempt that, I wonder if it will self discharge?

Paul Lenz Posted at 7-17 12:50
Hi Tony,
I succeeded to check the pins in the middle with an oscilloscope. I found out that there is a bunch of pulses every second if I use a working battery. But there are no pulses if I use the battery I am talking about. That means, all battery cells are OK, but a chip for communication is out of order. And I am afraid, this can not be repaired

Sorry to hear that. Though we don't recommend repairing the battery on your own but hopefully you can get some good advice from your co-pilots.

DJI Tony Posted at 7-17 22:08
Sorry to hear that. Though we don't recommend repairing the battery on your own but hopefully you can get some good advice from your co-pilots.

Don't worry. I think I will keep this battery for other projects where I need a powerful source for more than 12 Volt.

In one Facebook group I got the advice to contact DJI support. To be honest, I doubt that the DJI suppport will help me, or what do you think? For which reason you asked me for the serial number?

Get a CP2112 and re-flash the firmware to it. There's youtube videos on how to do it. The CP2112 is only $10.

Paul Lenz Posted at 7-18 11:29
Don't worry. I think I will keep this battery for other projects where I need a powerful source for more than 12 Volt.

In one Facebook group I got the advice to contact DJI support. To be honest, I doubt that the DJI suppport will help me, or what do you think? For which reason you asked me for the serial number?

Yes. It's a good idea to contact our support for a second opinion. Please go to this link to get some assistance with them. I asked for the serial number of the battery to confirm if it's an official DJI battery and if we can get that replaced using the manufacturing warranty however it's already out of the warranty period.

DJI Tony Posted at 7-18 19:57
Yes. It's a good idea to contact our support for a second opinion. Please go to this link to get some assistance with them. I asked for the serial number of the battery to confirm if it's an official DJI battery and if we can get that replaced using the manufacturing warranty however it's already out of the warranty period.

Thank you very much for this link. But what should I click? Repair requerst, Exchange service, or what?

Paul Lenz Posted at 7-19 03:54
Thank you very much for this link. But what should I click? Repair requerst, Exchange service, or what?

Sorry for not giving enough details. Scroll down until you see "Contact us". You can select either online support via chat or "Hotline Service". There should be a list of numbers you can call (if you're in Germany:
+49 (0) 9771-906 990). Just to give you a heads-up, the battery is already out of warranty but you can check with them if you want further help.

MaCJaX Posted at 7-18 19:12
Get a CP2112 and re-flash the firmware to it. There's youtube videos on how to do it. The CP2112 is only $10.

I am afraid to bother with a dead horse (and that's also why I hesitate to call the support).
Between + and -, there are 2 pins named SCL and SDA. Both pins show a lot of pulses if I use a battery which is OK. If I connect the battery I am talking about, SDA has constant 3.3 Volt and SCL has constant 1,0 Volt.
Especially the last value is irritating, it should always be 0,0 Volt or 3,3 Volt, nothing else.
That's why I suppose, that something is seriously broken.

MaCJaX Posted at 7-18 19:12
Get a CP2112 and re-flash the firmware to it. There's youtube videos on how to do it. The CP2112 is only $10.

Could you post a link please?
Doesn't matter, one was easier to find than I imagined it might be.

Sean-bumble-bee Posted at 7-19 09:00
Could you post a link please?
Doesn't matter, one was easier to find than I imagined it might be.

Sure,

Here is an Amazon link for the CP2112. It's a little cheaper on eBay but it ships from China. I know you're in the UK so you might want to search for this on UK eBay:

https://www.amazon.com/Teyleten- ... ps%2C479&sr=8-4

Check this video out on how to access the battery with the CP2112:

MaCJaX Posted at 7-19 14:29
Sure,

Here is an Amazon link for the CP2112. It's a little cheaper on eBay but it ships from China. I know you're in the UK so you might want to search for this on UK eBay:

Many thanks.

DJI Tony Posted at 7-19 04:23
Sorry for not giving enough details. Scroll down until you see "Contact us". You can select either online support via chat or "Hotline Service". There should be a list of numbers you can call (if you're in Germany:
+49 (0) 9771-906 990). Just to give you a heads-up, the battery is already out of warranty but you can check with them if you want further help.

I tried, but they don't want to help because the battery is from 2019.

MaCJaX Posted at 7-18 19:12
Get a CP2112 and re-flash the firmware to it. There's youtube videos on how to do it. The CP2112 is only $10.

I installed the DJI assistant and refreshed the drone firmware. The program worked until 82%, then it gave the message "Battery update error" and stopped refreshing.
So I am sure, also a CP2112 would not help.

Paul Lenz Posted at 7-20 01:46
I tried, but they don't want to help because the battery is from 2019.

Sorry to hear that. We are more than glad to help you, however since the battery is already out of warranty, we cannot get it replaced. Thank you for understanding

Paul Lenz Posted at 7-20 01:51
I installed the DJI assistant and refreshed the drone firmware. The program worked until 82%, then it gave the message "Battery update error" and stopped refreshing.
So I am sure, also a CP2112 would not help.

Yea, I agree. It sounds like the battery is defective.