I had a chat to one of the installers at a Pt Chev cabinet in the weekend and confirmed that there is no battery backup for the ADSL equipment, pots service will still be from the exchange..
I wonder, am I the only person that *really* wants to know exactly what is happening in any power failure?, has lots of backup power at home and would be lost without an internet connection at such an exciting time?
I could be all serious and say that In a wide area power outage I need it for work, being based at home and all, wireless backup it will have to be I guess

If you go down to the street and look at the cabinet it has two big doors on the front. Look around on the right-hand side and you will see a third door. This door hides the batteries to keep all the equipment running when the power goes off. Depending on the amount of equipment in the cabinet and the number of b/and customers connected the cainet will keep working for something like 6-12 hours.
Mind you if the power is off for that long, broadband availability is going to be the least of your problems.
However, if the power company has a meltdown - like it did in Auckland several years ago - the cabinet has a generator input - so Telecom's contractors can plug a gen-set into the cabinet to recharge the batteries and keep it all going.

Rest easy, you can use your laptop in the dark ...