The good old Mavic controller drain with android issue

Stacy · Feb 29, 2020

Keule said:
No need to buy an additional external power bank. Just use the Mavic Batteries and the USB adapter ...

Yes thanks, I actually thought of that. But that method kind of uses up my third battery anyway, defeating the purpose.

cadbob · Feb 29, 2020

One would think they should be data only. If your Droid is Rooted there is software to turn off the usb charging you could install also

lobstaman · Feb 29, 2020

I use a Galaxy S7 Edge and I can drain all 3 mini batteries flying and still have 2 lights left on the controller. Same cable that came with the mini.

Air Dog Two · Feb 29, 2020

Sometimes the simplest solution is the best. I'm going to try this sometime soon.

Quick and simple non-destructive mod for a data-only (no power) USB cable

I didn't come up with this myself, I read about it a long time ago somewhere on the 'net and I can't remember where/who (sorry). I thought I'd pass it along though since it's a great idea. Some boards and LCD screens will continue to be powered through the USB cable even when you turn your 3D...

folgerforum.com

cadbob · Feb 29, 2020

You could go but a cheap cable at a drug store or walmart and pull the pin on it. Maybe just throwing an idea at ya

Stacy · Mar 2, 2020

I'll

Air Dog Two said:
Sometimes the simplest solution is the best. I'm going to try this sometime soon.

Quick and simple non-destructive mod for a data-only (no power) USB cable

I didn't come up with this myself, I read about it a long time ago somewhere on the 'net and I can't remember where/who (sorry). I thought I'd pass it along though since it's a great idea. Some boards and LCD screens will continue to be powered through the USB cable even when you turn your 3D...

folgerforum.com

Tried this. Unfortunately, you need the power wire present for Android to recognize a device is connecting. The part that is missing is software that will prevent the controller from attempting to charge the phone.

cadbob · Mar 2, 2020

Bummer if you were rooted there is software to stop it from charging. Other than that have to go to Apple

DanMan32 · Mar 2, 2020

The drain issue with Androids is not DJI's fault. It has to do with adhering to USB specs and Android SDK lacking the ability to manage power draw like it is for iOS, and few Android manufacturers providing means of disabling charge without having to root the phone.

USB specs require an A device be capable of providing 500mA to a connected device. The RC has its USB in A/OTG mode.

Many Androids require power to be present on the USB bus in order to acknowledge and use the USB data. If you can manage to limit the available current to the phone without significantly dropping the voltage, that might be the answer.

DanMan32 · Mar 2, 2020

CareyL said:
Plug the power last. Stops all extraneous drain and keeps your phone/tablet at 100%

I strongly caution against this. The RC is wanting to provide power, but in this setup, you're pushing power upstream into the RC, against what the RC is pushing out. So far Carey hasn't had trouble, but who knows the damage that could be occurring long term to the power circuits or the RC battery.
What would likely work is provide power to the phone only from the power bank, isolating power coming from the RC. Just don't provide power to the RC from the power bank while the RC is in A/OTG mode.

Stacy · Mar 2, 2020

DanMan32 said:
The drain issue with Androids is not DJI's fault. It has to do with adhering to USB specs and Android SDK lacking the ability to manage power draw like it is for iOS, and few Android manufacturers providing means of disabling charge without having to root the phone.

USB specs require an A device be capable of providing 500mA to a connected device. The RC has its USB in A/OTG mode.

Many Androids require power to be present on the USB bus in order to acknowledge and use the USB data. If you can manage to limit the available current to the phone without significantly dropping the voltage, that might be the answer.

It is DJI's fault.

A small drain can be accomplished without the accessory actually charging the host. Is the controller the host? Or the accessory? For example a USB camera with it's own power supply (I have a few) does not charge the Android device. A small (tiny) current is present and all that is required.

DJI simply want's to bury their head in the sand and say they can't do it.

USB host and accessory overview | Connectivity | Android Developers

developer.android.com

Gooner21 · Mar 2, 2020

Why don't you just ensure the phone is at 100% befofe you going flying, I'm sure you charge the batteries for the Mini, just make sure you plug in the phone at the same time.....

I use 4 batteries and the controller only uses 1 or 2 lights of power on the controller and battery doesn't drain much at all (s9+)

xavenged · Mar 3, 2020

Why is the controller able to charge anything? I can charge my e-cigarette from my RC. That's f'n stupid.
This could be fixed with a simple firmware update to make the RC the accessory instead of the host. Therefore the phone would charge the RC. I'd much rather have that be the case. I own a oneplus 7 pro which charges extremely fast compared to the RC...

kerrylaw7307 · Mar 3, 2020

Has anybody looked into opening the RC, and tapping into the power wires, and adding a power plug for an external power pack? Seems the problem is the draining of the RC, so if the RC had 2x or 3x its current MA capacity, by adding and external power pack, it wouldn't matter that is is "charging" the phone. I know the RC uses 2 LI-on batteries, ( 18650). Just add an "external battery plug", and use, by plugging in a pair of external 3.7vdc batteries, during flight, but disconnect it when charging the RC. Thoughts?