[eartick]

You did not mention chargers.

Surely this battery system was not powering the 48vdc grid continuously? Life span of these would be nil. Had to have a battery charger from hell to keep them topped off

Of course all the switch gear in the nation (electric grid, pumping stations) use 12vdc charger battery BACKUP system

[Myrddin]

The CO has a room full of rectifiers powered by the commercial grid to keep the batteries charged. Most offices have a standby diesel generator to cover loss of commercial mains with a nominal 3 day fuel supply.