96Boards has posted several possible sources for a supply, and I am sure Arrow will have one soon. https://www.96boards.org/products/accessories/power/
The 410c has a wide range input, it will operate with any DC voltage between 6.5 and 18V, the supplies on the list are nominally 12V.
The thinking behind the choice of specifying a Wide-Range input is interesting: The board has GPS, and GPS is not very useful for a stationary piece of equipment, but is really useful on something that is moving. If the 410c is moving you probably won't have a place to plug it in. With other Single Board computers you need to condition your battery outputs to create a supply appropriate for the board, with the 410c just connect directly to the battery.
Common battery chemistries that will work are, 12V Lead-Acid, 7.2V Li-ion packs, 9.5V Li-ion packs, 14.4V Li-ion packs. Make sure the voltage drop on the wires between the battery pack and the 410c is not excessive (use short, fat wires), otherwise the supply at the board may brown-out and cause your app to crash.
As mentioned above you will also note that you can power the board from the low-speed connector. In general we expect the 410C to provide power to any connected mezzanine board, but if the mezzanine board uses a lot of power (say a controller that drives several hundred watts to the anti-gravity generators on your hover-board), then the mezzanine board can drive power into the 410c. Low-Speed connector pins 36,38 are wired in parallel to the center pin on the DC Jack (SYS_DCIN), and pins 39,40 are wired in parallel with the barrel of the DC jack (GND).
A word of caution: while the 410c board will operate on a wide range of inputs, the mezzanine boards attached may not be so forgiving. If you build a battery powered system check the specifications on the Mezzanine boards, make sure they can work with SYS_DCIN that matches your power source.