USB cable with P2 battery Charger?

[scooter339]

I got the batteries and 2 chargers. Each package had a USB cable looks like a USB3 to a mini.

What's it for?

 

[mcmax20]

Yeah I wondered that as well because its not battery related at all! It's just to do the updates on the phantom, controller, & iOSD. You should have one already since it came with the P2.