One of the great benefits of the SP-PRO Gen. 2 is that you can charge you iPhone or Android from the gimbal. We have recently discovered there is step to using this feature so it's NOT just plug and charge.
Install the phone to the gimbal with the smartphone charge cable connected on both ends (phone and gimbal). Then power on the gimbal and ensure the phone is connected via bluetooth. Once you have done this, please disconnect charging cable from the gimbal only then immediate reconnect to gimbal. This will activate the charge.