Can I power my Reason ONE alarm clock using a portable power bank?

Yes. Using our PowerPack Ambi 10K power bank (with cell capacity 37Wh), we were able to power the clock for 25 hours in standby mode (with clock display on; without music play). Standby current approx. 250mA at 5V. Moreover, the PowerPack Ambi sustained continuous music playing (via Pandora streaming) of the Reason ONE for 22 hours.