"Harry Bloomfield"; "Esq." wrote in
message ...
Ray used his keyboard to write :
But not for long, nothing like as long as an exchange can do that.

I agree, the size of batteries in a big exchange used to be vast back in
the GPO days. Entire basements filled with massive banks of batteries. 3 x
1 copper busbars run around the racks.

And usually with an on site generator that is used
when the mains is not available for long enough.