broadband battery backup

[#1]

I've just bought a Broadband battery backup from Vodafone (UPS) but am very disappointed to find that the pin does not fit into my router (too big). The router is a D-Link M60, and it looks like it takes a 3mm or 4mm (can't measure it clearly) instead of the 5mm provided on the Vodafone backup.  Anyone know if it's possible to get an adaptor that would make it possible to use this device?

(I can't find any way to ask this question of Vodafone, which has not been a good start.)

[#2]

Assuming that the barrel jack supplied with the UPS is the common 5.5 x 2.1mm, then adapter sets can be found on Amazon & eBay. As well as getting the correct fit, make sure that the actual voltage is correct too. Nearly every barrel connector has +ve to the centre pin these days, but it's worth checking that too.

This set has 3.5 & 4mm OD adapters...

WANGCL 8 in 1 Barrel Jack Adapter, 5.5 x 2.1mm Universal DC Barrel Connector Jack, DC Tip Set Socket...

[#3]

thanks for your feedback.

I tried contacting D-link to check the size of existing pin and they didn't know - just thought that it most likely uses a 5.5mm outer barrel with inner pin being, most commonly 2.1mm (or possibly 2.5mm).

The pin on the battery backup > router cable is quite a bit larger, looks like it could be 3.00mm inside.

This is not precise enough for my liking.

I do have exact voltage.amp/power specs, but no idea how to check  +v centre pin. I'd hate to get anything so specialised wrong.

[#4]

@citroenDS2 

Look at the device, you should see something like below to confirm polarity.

[#5]

that was helpful - it's positive!