The Stages SB20 USB ports are specified to charge at 5V, 2.1A. This value is equivalent to a 10W charger. This is the current charging voltage for most Apple phones and the following Apple devices:

  • iPad Air 2
  • iPad Air
  • iPad mini 4
  • iPad mini 3
  • iPad mini 2
  • iPad 2

For the newer generation iOS tablets, charging requirements have increased from 10W to 12-18W. This will result in the perceived inability to charge or maintain a charge while plugged into the bike's USB ports. 

It is recommended to pre-charge the device with the manufacturer-provided wall charger and limit overall ride duration, depending on the Apple tablet model and charging requirements. For most smaller devices, the bike's USB ports should provide more than enough charge to charge your device while using it during a ride.