IT'S the most annoying thing about getting connected to the national broadband network - a bulky power box on your lounge room wall.
But 10 months after NBN Co warned that the unsightly wall warts were causing customer complaints, the government is yet to decide whether they should remain compulsory.
NBN Co chief executive Mike Quigley warned last October that the large battery back-up and power unit was the single biggest source of complaints from users in test sites.
The power unit keeps a telephone line active for about five hours during a blackout. But it is a large bulky box that is not necessary for connecting to the internet and many households may never use it. About 64 per cent of calls to triple-0 were made from mobile phones in 2010-11, according to the communications regulator.
A spokesman for the Department of Broadband said the government had consulted with a broad range of interested stakeholders to gauge attitudes to battery back-up.
''The government is carefully considering all stakeholder views to determine the best long-term deployment model and will make a decision shortly,'' he said.
NBN Co's updated corporate plan, due out tomorrow, may reveal a change in policy.
NBN Co said batteries were still mandatory in every house. If they were optional, households could plug the smaller network box straight into a power socket. The telco industry would prefer an opt-in approach as long as consumers are fully informed about what happens during a blackout.
The government ordered power units to be installed so the NBN would mirror what happens on the copper network during a blackout.
Copper wires carry electricity and remain active when household power goes down, which keeps telephones working.
But the copper wires will be removed once households are transferred to NBN Co's fibre-optic cables.
Fibre-optic cables carry light, not electricity, and are useless during a blackout.
Copper telephone line will be kept for at least 10 years in rural and regional areas where households will get wireless or satellite broadband instead of fibre-optic cables.
Mr Quigley argued last year that there would be a lot of batteries deployed for ''little return'' because many people no longer use fixed telephones.
''The big issue is the box … which is the battery back-up. That is the thing that most people object to, which is something we obviously need to be talking to the government about how we address that,'' he said last October.
There is also a huge cost associated with the batteries and an environmental impact, with at least 10 million 12-volt lead acid batteries needed. These batteries must be replaced every five years.