ONT Battery Backup

[Les-Gibson]

I'm on FTTP with both an ONT and BBU, my phone is currently on copper but I have recently been informed that I will be going onto DV soon.

I noticed this morning that the red 'Fault' LED on my BBU is lit, I tried changing the batteries but that made no difference. Can someone please advise if I am correct in thinking that the BBU was for FVA only and that it won't make any difference to DV if I remove it?

My thinking is that DV requires my SH2 hub to be powered in order to work and therefore the battery backup is surplus and can be permanently removed ?

[gosforth · Accepted solution]

@Les-Gibson in order to have fully working DECT (Digital Voice is over this), you need have either working BBU on ONT, and, also SH2, which can’t be done other way, then backup UPS for it…

Means, in case of power fault, DV over SH2 DECT will fail, even if you have BBU fully working…

That’s something I believe, could raise concerns, but BT here hold premise, as You have at least mobile phone, to backup in such case (which should be backed up for some sort of power failure, at least for some time, on infrastructure mode)…

[Keith_Beddoe]

@gosforth 

This is the BT backup for the SH2 https://community.bt.com/t5/Landline/I-can-t-connect-to-Digital-Voice/m-p/2161430#M76686

The ONT, of course, would still need power, so a mains output UPS would be a better option, as it would power both, provided they are near each other.

There are plenty to chose from.

[Les-Gibson]

@gosforth 

That's what I thought but thanks for confirming.

I agree with your concern about power cuts, we have mobile phones on different networks in our house and not one of them gives us a good mobile signal so all calls we make from home are routed through Wi-Fi, obviously this isn't going to happen during a power cut, let's just hope we don't have an emergency.

[Les-Gibson]

@Keith_Beddoe 

Thanks for that Keith but I don't think it would power both the ONT and the SmartHub 2, I notice from the spec that it's only rated at 2A, the SH2 power adapter alone is rated at either 2 or 2.5A (can't remember which offhand) so that doesn't leave much to power the ONT.

It also seems a bit on the expensive side for what it is, it would be cheaper to knock up a couple of power leads reclaimed from old devices and keep a 48VA car battery charged up in the garage.

[Keith_Beddoe]

Its only designed for the SH2, and as for the cost, I would expect it to be "loaned" as most other BT kit is. But there is likely to be specific criteria, like a poor mobile phone coverage, or a care alarm or similar. Its very simple for the end used to connect up, with all the correct leads.

For the price or less, you can buy a mains UPS, however many are not designed to run more than 20 minutes, even with no load.

Providing an alternative, which is consumer friendly, would present a problem, as you cannot expect people to wire up a couple of 12v leads, even if they could obtain the correct plugs.