NBN Co CEO Mike Quigley has revealed mandatory back-up batteries as the biggest source of complaints from trial users of the National Broadband Network.
The batteries, installed at more than 800 premises on the mainland during the NBN trial phase, were designed to power the voice ports on the network termination unit attached to a house in the event of a blackout.
However, they were largely unused by residents in the first release sites who used VoIP telephony, wireless handsets and mobile phones instead of low-power analogue phones.
The first opportunity for users to test out the voice ports and battery back-up came this month.
Even those who planned to use the voice ports on the NBN doubted the battery's purpose.
Quigley told attendees of the Commsday Summit in Melbourne that users had complained about the size of the boxes and the requirement to replace the battery after five years.
"That is a thing that most people object to which is something we obviously need to be talking to the Government about how we address that because it is probably the biggest complaint we get," he said.
"There's potentially a lot of battery backup units being deployed for little return."
The Federal Government planned to consult on the issue but required NBN Co to install the back-up batteries at each fibre-connected premises as an interim measure.
Representatives of the Department of Broadband told a Senate committee in February that a discussion paper was being prepared.
A spokesman for communications minister Stephen Conroy could not clarify this week when it would be released.
The interim measure remained despite concerns from the Greens in February that it would leave landfills full of millions of disposed batteries in several years.
Should it continue across the full rollout of the network, a backup battery device would be installed at each of the more than 12 million premises NBN Co expects to pass with fibre by 2021.
Quigley argued that the batteries would still be required in cases where NBN users wished to use a voice-only service through an older telephone.
Telstra had provided a similar backup unit as an option to residents in the South Brisbane fibre rollout area, while maintaining batteries to premises where they were deemed a medical necessity.
NBN Co continued to discuss the issue with Government but Quigley told iTnews that the network builder could not alter current arrangements without a policy change.
"We can say, 'Here are the pros and cons of what we see', but it's a Government decision," he said.
"As long as this issue is resolved even within the next year, it's not a big deal."
The network wholesaler has not yet signed mass supply contracts for batteries.