cDAQ-9188 UPS?

Anyone have any recommendations on adding battery backup power to the Ethernet cDAQ chassis?  I was thinking of something like the PicoUPS-100 by Mini-Box, a 15V power supply, and sealed lead-acid battery.  Has anyone tried this or similar and had any luck?  It should certainly be more power efficient than an AC UPS.  It's a shame NI doesn't source something like this.

Thanks,

Erik