The stock adapter is +12VDC 0.75A. I tried hacking in a +12VDC 1.75A transformer for faster charging rates but the device failed to do anything. I re-spliced the stock transformer and it still works. With daydream activated the keystone maintains to drains the battery as it cannot provide enough charge to power the device. For $49 this product is a compromise to failure in wireless charging technology due to charging rate and slick surface.
Battery Mix reports +/- 10%/hour charge
Inside the device. The back pops right off with a proper tool. Notice the 3 temp sensors between the coils.
Underside of the circuit