EE Smart Hub USB powered

[Beliskner]

I need to power our EE Smart Hub for an extended period while we have a bunch of electrical work done. I think the easiest option is a USB to 12v barrel adapter and a big power bank. Has anyone successfully managed this? Does anyone know what size the barrel adapter is and what the peak power draw is? The mains adapter is 2000mA, but that's not necessarily what it needs. 

[Mustrum]

If you look at the plug it says 12V 2.0A 24W so even if you did get it working, your power bank is not going to last long.

[Beliskner]

Yes but the 12v is pushed, the Amps are pulled. Amps (and by extension Watts) are somewhat irrelevant on the supply side so long as they're more than the peak draw. 

I have the router plugged into a power genie and it says peak power was 11.2W, but that includes transformer and rectification losses. But I've no idea how much the losses actually are. 

[mikeliuk]

Hi @Beliskner ,

Your best play would be to use the APC UPS calculator to work out what size battery you need for the runtime you require.

There are some large lithium-ion power banks around for £100 to £400 to avoid the need for lead acid.

A mobile phone WiFi hotspot may be more practical if you don't have a 4G LTE mobile router with battery and both options should give better runtime than a device intended to be mains powered.

Perhaps another play would be to ask to borrow internet access from a sufficiently nearby neighbour. Good luck!

https://www.apc.com/shop/uk/en/tools/ups_selector/

If the calculator suggests it will be big enough, a nice consumer APC UPS is the BE850G2-UK which I have for multimedia equipment.

[Beliskner]

Thanks, I actually already have an APC UPS and it's fine for about 2 hours of power loss. The issue is inverter efficiency absolutely plummets below 20% (check the APC load efficiency graphs) and I'm using about 3% so I might actually be drawing 2-3 times more power from the battery than is actually being consumed by the router due to the inverter, rectification and a voltage changes. 

Fortunately the UPS has USB power out so would totally bypass the inverter hence my question. Plus the bonus of using the 20000mAh tablet boost battery if required. 

As for 4G and neighbours, we're rural. 4G isn't a thing here and no neighbours are close enough for WiFi to reach our office space.