As the Juicepack Pro lost about 75% of its endurance over about a year, I went ahead and cable tied a Powerstation Pro to the backside. Battery problems solved. After the mod I could ride with GPS/Wifi enabled/Bluetooth music/Data enabled, with total impunity. Pictured is an Iphone4, with Spigen glass screen protector, with Invisible Shield back case protector, with Juicepack Pro (transducer covers and plastic screen removed), with Powerstation Pro. The cable ties were 8 inch, and I had to use 4 of them. If cinched too tight, it could bubble up the Spigen glass screen protector as it warped the adhesion and allowed some air in. I basically never used the internal battery for a year, just kept it on constant charge via the Mophie Juicepack Pro. Wearing the Juicepack down instead of the internal battery. Due to that habit, the internal battery is still in very good health. Still holding out on a Juicepack Pro for Iphone 5/5s/etc.