I have tried 2 battery extenders for my Osmo+ and neither one will turn the Osmo on.  I have it hooked to a Phantom 4 car charger. The light is on on the car charger, but the Osmo gives a couple beeps but will not turn on.  Is there a problem with these units or am I doing something wrong?  I have firmware version 1.3.0.50

Does your Osmo+ function normally with battery?  Also, try plugging  your Phantom 4's   charger (The cable that charges controller) on your Osmo battery extender.

DJI-Thor Posted at 2016-12-12 21:33
Does your Osmo+ function normally with battery?  Also, try plugging  your Phantom 4's   charger (The cable that charges controller) on your Osmo battery extender.

Yes, it works fine.  And I followed all instructions that came with it, including  plugging it in as directed.

What I did find when it was plugged into the power point in my truck and the green light is on on the charger is that the Osmo only beeps a couple times and turns off.  The power point is live all the time in a Ford truck, but the adapter does not supply enough power to start the Osmo using the adapter without the truck running.  I also tested it on a full size, fully charged truck battery on the counter and found the same thing. I need to have a battery charger hooked up and running to get the Osmo to turn on.  

I have a cabin with solar panels on 12 volt batteries and always used them to charge my Phantom 2 batteries with a car charger and a power point.  This is where I was going to use this car charger and battery extender, but the Osmo won't start there either, just a couple of beeps and turns off.   I also use a 600 watt some power inventor and my house charger on my P2 and it works great.

In conclusion, the P4 car charger is not a good way to power the battery extender.  Really don't want to leave a full size truck run to power a camera.