Hello! I'm having issues with my new Mavic 2 Pro's controller. Yesterday I was flying my Mavic and after the first flight the controller battery dropped from 100% to 55%. Four hours later, on my second flight I was forced to land my drone with 47% battery left because the controller's battery dropped from 55% to 4%. It was like 1% drop on every 15 sec. I'm using Android phone (Huawei P20) btw.
I left the controller on the desk and it magically started to regain some juice - an hour later it was at 7%, today it shows 22%.
I will charge it right now and try to refresh the firmware. Any suggestions? Maybe I should reach out local DJI Store for warranty replacement?
Regards

Hi, we're very sorry to hear about the unpleasant experience that you had with your Mavic 2 Pro's remote controller. Regarding your concern, I suggest you refresh the firmware of your remote controller via DJI Assistant 2 so we can check. Also, check and observe your phone if it's charging while connected to the controller. If the issue persists, I'm afraid that you may consider it sending for repair. You may contact our support at www.dji.com/support for further help. Thank you.

I know that the controller has to send power to Android phones to keep the USB connection active. Doesn't have to with iOS. You also have the option to turn on or off phone charging from the controller with iOS, not sure if option there on Android. Sounds like the phone was demanding a lot of juice?

You are right about the Android devices, it's constantly charging the phone and that can't be disabled by the GO App. Still, it's not possible to drain the battery that fast.
I've refreshed the firmware and I'll test tomorrow if the problem still exists.
EDIT: Just tried again with connected phone to the controller (without connecting it to the drone) after the firmware refresh. The battery drain is about 3-4 %/min. Now I don't know what to do

Sounds faulty.  You could try using the other usb port on the control to hook to your device.  There's the one on the side and one below where the sticks can be stored.  Good luck

Mickey7 Posted at 1-2 11:38
You are right about the Android devices, it's constantly charging the phone and that can't be disabled by the GO App. Still, it's not possible to drain the battery that fast.
I've refreshed the firmware and I'll test tomorrow if the problem still exists.
EDIT: Just tried again with connected phone to the controller (without connecting it to the drone) after the firmware refresh. The battery drain is about 3-4 %/min. Now I don't know what to do

Hi, thanks for the updates. The reason why the Android devices have no option disabling the charging mode due to it was related to the android system and hardware. The Android phone needs on-going 500mA to maintain the USB connection, so there is no option for the Android device to disable the charging mode. If the problem will persist, please contact our support using the link above that was mentioned on the post #2. Thank you for the support.

Always use a fully charged Android phone, make sure fast charging on the phone is switched off.

The RC should be good for four batteries before it reduces to about 20 - 30%. You can use a 25% AC battery plugged into the side port to charge the RC. Use the bottom sub to connect to phone.

actually I can confirm that the radio controller of mavic 2 has an excessive consumption of batteries,
I have several dji drones, but this is the first to have an excessive consumption and I do not think depends on the possible charge of android device..
probably its transmission system (better of previous models) has a higher consumption,
however I do not think it is a serious problem, it should be able to complete flight about 3-4 batteries. (I have not verified yet exactly )

radio controllore 3950 mAh battery is declared
Operating current / operating  1800 mA
So you will have an autonomy of about 2 hours = 4 batteries