Hello, I have a Matrice 300 RTK drone with the Smart Controller with the built-in extension for hot-swappable batteries.  The internal battery has run down, and this is normally charged by the external batteries when connected.  It seems this only works while the remote is on, but it shut itself off automatically without really charging.  Now it has stopped booting at all, with only a blinking LED when the power button is pressed.  According to a manual I found online, it seems like the internal battery should be able to charge from the USB-C port on the extension, but this has not worked for me.  How can I charge this remote now?

Yes the external battery is only charging the internal battery while the RC is powered on. This is a dumb design choice by DJI in my opinion. You can charge by the USB C port on the side of the RC but I've found that it is really picky about what USB brick is being used. Your normal low watt iPhone USB adapter isn't going to cut it. Find a higher wattage plug and it should work.  

Johnnokomis Posted at 2-9 21:45
Yes the external battery is only charging the internal battery while the RC is powered on. This is a dumb design choice by DJI in my opinion. You can charge by the USB C port on the side of the RC but I've found that it is really picky about what USB brick is being used. Your normal low watt iPhone USB adapter isn't going to cut it. Find a higher wattage plug and it should work.

You have to use the provided USB charger you got with your M300 or RC. Other won't charge as W is not enough.

Arnor Posted at 2-10 01:47
You have to use the provided USB charger you got with your M300 or RC. Other won't charge as W is not enough.

Which kind of removes "Universal" from the name "Universal Serial Bus".

Johnnokomis Posted at 2-10 04:39
Which kind of removes "Universal" from the name "Universal Serial Bus".

Universal connector but it needs lots of juice...form vs function? :-)

FYI I quickly scrolled through the Wikipedia USB-C, the voltage and Amp are not standardised :

"All USB-C cables must be able to carry a minimum of 3 A current (at 20 V, 60 W) but some can also carry high-power 5 A current (at 20 V, 100 W)" src. https://en.wikipedia.org/wiki/USB-C

Arnor Posted at 2-13 22:21
Universal connector but it needs lots of juice...form vs function? :-)

FYI I quickly scrolled through the Wikipedia USB-C, the voltage and Amp are not standardised :

Right but a slow charge is actually better for a batteries health (trickle charging?) These are only 3.7V 18650 cells inside most DJI RC's after all.

Johnnokomis Posted at 2-14 04:56
Right but a slow charge is actually better for a batteries health (trickle charging?) These are only 3.7V 18650 cells inside most DJI RC's after all.

ps : I only charged my 2 RCs like 2 times ever :-) Always using the external battery

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Johnnokomis Posted at 2-9 21:45
Yes the external battery is only charging the internal battery while the RC is powered on. This is a dumb design choice by DJI in my opinion. You can charge by the USB C port on the side of the RC but I've found that it is really picky about what USB brick is being used. Your normal low watt iPhone USB adapter isn't going to cut it. Find a higher wattage plug and it should work.

Please i need help on this same issue. 07061510577