Fttp ONT showing red fault light

[#1]

I have fibre to the premises. The ONT is showing a red fault light (although I can at the moment get online).  My neighbour had a similar problem and the engineer said the internal battery was not recharging and had to renew it. Please can you help.

[#2]

I’m afraid replacing the batteries is your responsibility.

There a BT guide here https://www.bt.com/help/landline/fibre-home-phone-service--questions-about-the-battery-back-up-un

There’s a long Openreach guide here https://www.openreach.co.uk/cpportal/content/dam/cpportal/public/images-and-documents/home/help-and-... that ultimately says “Replacement of batteries is a customer responsibility.”

The OR guide also says “An alternative to replacing batteries is to remove the BBU in its entirety and plug the power cable directly into the ONT.” New installs don’t get a BBU now.

[#3]

AFAIK Plusnet don't provide the home phone service over the Fibre, its still provided over the physical copper line.

In which case there is no point in the BBU, UNLESS your router and other equipment is also on the battery backup!

There's a useful thread here https://www.ispreview.co.uk/talk/threads/new-openreach-ont.36099/ discussing the various ONT models and whether the BBU is easily bypassed.

[#4]

There’s the edge case that with a laptop you could establish a PPoE connection direct through the ONT. But during a power supply interruption I think I might have other priorities.🤣

[#5]

@tire-some Are you still having issues? Our tests aren't showing any issues and the connection logs are showing your router's been connected to the internet fine with a good amount of usage yesterday afternoon and last night.

[#6]

Yes, red light still on, but internet is working fine.

As mentioned, it must be the batteries that need replacing?  The top part of the outer cover which houses the bbu and ont compartments is screwed shut and is difficult to get to due to positioning of the unit right up against the wall in the corner of the room. As we don't use the fibre as a phone (for voice calls) do we need to have battery back up at all?

[#7]

Ah OK, the battery backup may be useful in the case of a power outage. 

[#8]

Not really, as discussed above, its only really useful if you have Fibre voice. To make any use of the backup for broadband you would need the other equipment like router to have a backup supply. As @edwh said, the only possible use would be a laptop wired in and configured for a PPPoE connection.

Not sure that's going to be your priority during the first hour of a power cut!!

[#9]

I am on FTTP with Plusnet and when we have had any mains power cuts the BBU has kept the power on to the ONT though not a lot of use if the power to the rest of the gear is off, though as this thread our BBU packed up and and would not charge the batteries, I removed it several months ago.

[#10]

@tire-some 

If you have the model I think, the flap at the foot lifts up to allow access to the cable ports.

If you look, you may see the power cable going into the BBU and then a smaller cable going from the BBU to the ONT. I think you can just plug straight into the ONT bypassing the BBU.

Brian