This topic

extension cable for CyberPower Battery Back-up

ThomasWendy15 — Mon, 02 Jun 2025 11:14:14 GMT

I now have battery back-up for my ONT, all items installed by OpenReach on behalf of BT but the cable (1.5m long) could conveniently be 50-100cm longer .. I would like to buy an extension cable but do not know what is the specification to fit the battery back-up. It is a CyberPower unit with identifier DTB24U12V-BT2. Can anyone help? I contacted CyberPower who advised me to contact BT have got nowhere with that!

Alternatively does anyone know if it is possible to obtain a longer cable, say 2 to 2.5m long? The ONT identifier is SN1ALCLFD5DCCD1.

Re: extension cable for CyberPower Battery Back-up

WSH — Mon, 02 Jun 2025 21:43:09 GMT

It is quite easy to buy a dc power male to female, (extension), lead off Amazon. The tricky thing is identifying the size of the plug you need. The common sizes are 2.1 and 2.5 mm but 3.0 mm is also out there. The way to do it is to use a metric drill bit as a gauge. Take the lead you already have and insert the bit in the plug. If a 3.0 doesn’t fit try a 2.5. If that doesn’t fit then it will be a 2.1 mm.

Re: extension cable for CyberPower Battery Back-up

ThomasWendy15 — Tue, 03 Jun 2025 10:33:42 GMT

Thanks for that suggestion.

I read that sometimes companies develop non-standard plugs to force customers to buy only their products. I was wondering if that is the case with the CyberPower battery, particularly as CyberPower technical help referred me back to BT as their battery for BT has been developed (they said) as a special joint project.

Re: extension cable for CyberPower Battery Back-up

WSH — Tue, 03 Jun 2025 11:13:58 GMT

Unlikely, but the plug on the Smart Hub2 and Home Hub 5a were 3.0 mm, which until recently, was an unusual size in this country. More an American size, I believe. The Home Hub 5b was a more common 2.5 mm, if memory serves. The EU, (or such), recently told companies to start standardising on a USB type C anyway, so that seems to further undermine the idea.

In my experience, if a company does a custom plug it's a completely different design and done for safety reasons, so people don't use an inappropriate charger etc.

Edit: Of course, you could post a picture of the plug if you are concerned. I'm sure someone will confirm or deny it's standard. A quick dig on the internet suggests it's a normal 2.1 but I'd check before you buy if I were you.

Edit2: This might be worth a read:

https://community.bt.com/t5/Home-phone-including-Digital/UPS-solution-for-ONT-and-SH2/td-p/2235065/highlight/true

Re: extension cable for CyberPower Battery Back-up

gowthamsundar — Wed, 04 Jun 2025 05:40:34 GMT

Hey!! The CyberPower DTB24U12V-BT2 uses a standard 12V DC barrel connector, likely 5.5mm x 2.1mm (centre-positive). you can get a 12V DC extension cable in 2m or 2.5m lengths. Make sure it matches the plug size and supports the current (2A or more)

Search for

“12V DC extension cable 5.5 x 2.1mm” on Amazon or eBay

Avoid super cheap/thin cables, as they might cause power cuts..