Picked up a MobArmor magnetic phone mount. Wanted something low profile and removable. $30.
Hooked a 6' micro USB cable to the Battery Tender leads under the seat. They make a USB attachment.
Ran it to the left side fairing compartment, drilled a 5/8" hole where your laundry money goes and fed the cable there for storage.
The mount has one side magnetic, one side 3M sticky. So I stuck 10 small rare earth magnets on the sticky side, now with the thin steel plate supplied by MobArmor, I can attach my phone to the tank.
The magnets were a little slippery, so I stretched the thumb from a nitrile glove over them, works better.