I have not tested it but the ONTE documentation certainly states that when on BBU only the phone access is maintained and the network is not.

You already have the power source (car) I assume? So if you want to keep internet access for a laptop during a power out then a USB mobile dongle + a car adapter/charger or inverter for less than £25 would work. Although a mobile dongle would is not that cheap to use on a regular basis, but a lot less than £100's or a lot more on a UPS backup system that would almost never get used.
Alternatively an iPad or similar with a sim card can be powered or charged from a car and then used indoors or buy a couple of powerbanks to charge from the car and use to supplement the iPad indoors. Also if you have got an iPad or other tablet then its got 365 day use as a bonus.

Edited by deleted (Thu 29-Sep-16 10:53:19)

In reply to a post by brightd:

I have not tested it but the ONTE documentation certainly states that when on BBU only the phone access is maintained and the network is not.

This is what I was told.

Easy solution, get a UPS and connect the power supply to it, then BBU won't get used and the ONT will still function normally. That said if the power is out over a wide area, how long to the modes have power for?

Is the phone through fibre as well as the FTTP, or is there a copper phone line?

If there is copper then an ADSLx backup connection with UPS may be an idea.

Coping with a two-week failure is definitely generator level. Not just for the broadband. How about central heating systems in the winter?

Often better to relocate if needing connectivity for a full working day, certainly running an inverter from the car is not a very efficient method, since if for any extended period you would need the engine running with attendant costs/risks.

If modes means nodes, for FTTP they are passive, and the exchanges where FTTP links back to backhaul should have extensive battery backup plus generator options.

Just to add , a post later rightly states that the purpose of the BBU is to power the ONTE for the purpose of running the FVA service .

Fair point, but could still use a charger rather than an inverter in the car to top up battery so then can relocate to house to use. If you have a second battery even better.

In reply to a post by MrSaffron:

If modes means nodes, for FTTP they are passive, and the exchanges where FTTP links back to backhaul should have extensive battery backup plus generator options.

Yes Nodes sorry. But that's good to know. Thanks.

In reply to a post by Zarjaz:

Just to add , a post later rightly states that the purpose of the BBU is to power the ONTE for the purpose of running the FVA service .

Am I right in thinking that FVA is a separate service that attracts a significant extra charge?