Most “Power Banks” I have seen output 5 Volts. The DragonBoard 410c needs at least 6.5 Volts to operate (anything between 6.5V and 18V will do), so you can’t use a power bank directly. Power banks usually have an internal 3.7V battery and then they boost this to 5.0V. You could put two power banks in series and get 10 Volts, this would make the DragonBoard perfectly happy.
The DragonBoard was designed to run directly on batteries (7.2V LiPo, 9.6V LiPo, 12V lead acid, 14.4V LiPo, etc). I have used a RC Car battery (7.2V nominal) and the RC Car battery charger to recharge the battery. You do need to add some wire and a connector to the RC car battery to plug it into the DragonBoard. This connector fits into the 96Boards power Jack http://www.digikey.com/product-detail/en/10-01071/839-1161-ND/3507727 (4.75mm OD, 1.7mm ID).
You could use a car battery (or plug it into the lighter socket in your car). You will need to build a power cable with the right connectors.
Note: The 96Boards CE spec requirement is for 8v-18V operation, the 410c DragonBoard exceeds the requirement. Some 96Boards designs may not operate from a 7.2V battery.
Full Disclosure. I am an employee of Qualcomm Canada, any opinions expressed in in this post or any other post may not reflect the opinions of my employer.