Hi again...
I've added the UPS 'backup boxes' now (two actually .... router/phone location & another for hybrid connect/discs, iMac etc) and they work a treat; I ever noticed the switch into battery and everything I'd connected worked. I've used an APC product from Broadbandbuyer ... the larger capacity units need a fan the low noise from which may or may not be an issue depending on the location. The smaller ones are silent and will last a few hours supplying the comms kit only.
@FTT You’re all heart mate. No need for all the sugar coating, just tell it like it is.
Above answer down not address the issue. What is needed if a technical fix to assure telephone comunication through a power blackout as given by the previous analogue service. The answer is surely a better backed up digital phone, modem and router so the communications line twisted pair or optical fibre can be driven from the customer end. The phone could be the cutsomers old phone again powered by the battery system and digitised for the internet connection. Its not rocket science and the market is definitely big enough to warrant the design.
Local telephone broadband masted often go down in a power outage leaving no mobile signal.
All suppliers that have switched to DIGITAL VOICE offer EBUL - EMERGENCY BACK-UP LINE. The Motorola fw500. This is a hybrid phone that has a SIM card also installed aswell as a rechargeable battery. It connects to the hub like a normal phone (some comes with a splitter) to plug in this phone plus your normal phone you use. When the power or broadband fails the phone switches over to line fault mode AND THEN AUTOMATICALLY RUNS ON THE SIM CARD (it's an iot SIM that roams all networks for the strongest) the phone also has built in battery backup.
BT are the only provider to also offer a battery backup unit. Wich there are 2 versions!
Version 1 -is for FTTC connections and is one unit to backup the BT smart hub meaning it stays connected in a power cut, however only an analogue phone would work not a phone that needs power.
Version 2 -is for FTTP customers and comes as a bundle, it comes with two units. One for the hub and one for the fibre modem.
Choosing the FTTC option yet having a FTTP connection will not work as the hub will stay on but not the fibre modem.