Only option you have for 908e products is to use a AC UPS system and/or then have that UPS hooked up to a generator system.
For future applications, use the NV 6360 which has a DC hookup built in to the chassis.
Hope that helps. Let me know if you have any other questions.
Unfortunately, the equipment was selected by the provider and they are pretty particular about it.
But I very much appreciate the reply. Thank you.