Brand New Faulty Bad Battery on P2

[Wind_Shear]

I've had two fail out of four.

The original that came with my P2NV, and another purchased as a backup.

First suddenly read 30,000 discharge cycles.

The second did exactly what you're describing.

I'm now on week 9 waiting for Robert @ UAVProducts to get me the first replacement and week 2 waiting for a DJI RMA on the second.

 

[Wind_Shear]

Exact same thing happened to me. I happened to be flying deep in the backcountry in the Everglades filming some porpoises herding baitfish 600 meters from where I was standing on the beach and at 8 meters altitude when I noticed I was suddenly descending. At 4 meters I gunned the throttle and didn't gain any height but stopped the descent, so I headed straight for the home point in my iosd display at full speed.

One of my closest calls to losing my bird.

 

[ElGuano]

I've heard there have been some P2 batteries with similar faults. They may trigger failsafe at about 50% discharge. Definitely contact your dealer and get a replacement, don't fly that pack.