I posted an earlier version of this modification a year ago in the general discussion forum. Someone revived the old thread and suggested I post it in this forum along with the newer mod photos. I have uploaded the part to thingiverse. http://www.thingiverse.com/thing:691506 The modification allows longer batteries to fit into the P1 and shifts the weight farther to the back to help balance the weight of a camera and gimbal. It requires cutting out the back end where the LED is mounted and attaching a 3d printed part with screws. The front battery compartment opening has been opened up slightly as well to allow taller batteries such as the Multistar 4000mAh to fit. With this battery I can get an easy 20 minute flight time, more if I pushed it. The battery was at 11.2 v after landing and came up to 11.3 within a minute. These batteries have a lot of sag so I had my first warning set at 10.7v.