Opening of the Way

Mouser Electronic
Modems
https://www.mouser.com/new/embedded-solutions/ethernet-communication-modules/modems/n-6vz2r

Alpha Microsystems
https://en.wikipedia.org/wiki/Alpha_Microsystems

^^^^  don't know if this still exists

this seems to be what I was looking for:
https://www.alpha.com/hardened-modems

https://www.alpha.com/products

YES
https://www.alpha.com/products/equipment/outside-plant-power

batteries
https://www.alpha.com/products/equipment/outside-plant-power/category/alpha-cell-batteries

Cable UPS Power Supplies
https://www.alpha.com/products/equipment/outside-plant-power/category/cableups-power-supplies

datasheet PDF, 12 volt batteries
https://www.alpha.com/download/outside_plant_power/alphacell_batteries/alphacell_hp/alpha_092019_alphacellHP_datasheet.pdf

Uniterruptible Power Supplies
Advanced ferro technology for maximum power efficiency under all modes of operation

https://www.alpha.com/products/equipment/outside-plant-power/item/xm3-1-hp-broadband-ups

History
https://www.alpha.com/company/overview/history

https://www.alpha.com/company/overview/about-alpha-technologies
Alpha Technologies
3767 Alpha Way
Bellingham, WA 98226



David Gilmor
https://www.youtube.com/watch?v=fLYeVk9Sk60