No electricity!

Telephone companies only use 48V because it's the highest voltage that's still reaonably safe.

Why did you go for 12V? 48V would have been much better as it would only use 130A rather than 520A, assuming 80% inverter efficiency.

The red batteries appear to be two cell units which will be connected in three paralleled series banks for 48V. This is odd because normally you can buy high capacity single cells but not two cell modules.

I think when it comes to the phone company, 48v requires smaller guage wire and that saves copper costs as well as allowing more twisted pairs per bundle, travels better via wires with lowered line losses. It's that ringing voltage that hurts!!

My RV runs on 12v and given that my group 31 deep cycle along with a group 27 battery as a standby, the inverter needs to input 12v. Most modern inverters are 90% or better efficiency with very low idle current. I don't own a Trace inverter but for camping I use a Vector model. For the home I have this monster industrial thing (can't remember the name right now), but it's a 19" rack mount unit that weighs around 50lbs!!! Pure angus beef!!! The PCB foil traces are thicker than some PC boards themselves!! Employs heavy duty magnetic breakers. The battery charger section is nicer than many "smart" automotive chargers.
If I ever hit the lotto- I'm gettin' me a Trace/Trojan setup as well as either a Winco tri-fuel genset or a Gillette genset ... or maybe I should just go for broke and get a 40Kw Kohler standby.