Question Would a UPS power two 3W light bulbs?

MrYossu

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Dec 15, 2013
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This isn't a PC question, but given the expert help I was given when buying a UPS for my PC, I'm hoping to get some help here on a similar question.

A friend of mine has a cupboard that includes two 3W light bulbs (the kind that are meant to look like flickering flames in case it makes any difference). There is a wire out of the back of the cupboard, with a standard (UK) 2-pin plug that goes into a wall socket and powers the bulbs. The bulbs are usually only on for a couple of hours each day.

However, he just moved the cupboard, and it's now no longer near a socket. It's not practical to install a socket in the new location, and he can't use an extension wire as it would be a tripping hazard.

He wondered about getting some sort of power bank to power the bulbs. Given the low wattage and low usage of the bulbs, the assumption was that a power bank would only need charging once in a while, at which point it could be taken out of the cupboard and recharged near a socket.

He tried a couple of power banks (didn't manage to find out exactly which ones, but I can try again if it helps), but neither of them worked. The lights just didn't come on. He was told that the bulbs were too low power to be used with a power bank.

Anyone any advice as to how he can manage this? I find the idea of bulbs being too low power a little hard to understand, but I'm no expert in these matters, so am willing to be educated.

Thanks for any advice you can give.
 
Many power banks do have a minimum load to stay active. They are expected to be charging something or have an active USB connection to keep them awake.

Might be able to get a small USB power meter that could keep it awake. And apparently this is enough of a problem that people have made tools for it:


Maybe just shop around for something similar.

Though might be easier to pick up some rechargeable battery powered decorative lights instead. Ones that have USB charging so you could just plug them in once in a while.
 
Many power banks do have a minimum load to stay active. They are expected to be charging something or have an active USB connection to keep them awake.
Ah, that explains it, thanks for the clarification.

Might be able to get a small USB power meter that could keep it awake.
Not sure what you mean. Please can you claify.

And apparently this is enough of a problem that people have made tools for it:

OK, will take a look.

Though might be easier to pick up some rechargeable battery powered decorative lights instead. Ones that have USB charging so you could just plug them in once in a while.
The problem is that the bulbs he has in there now are one that look like flickering candles, and the only battery-powered ones I could find are made to look like tea lights, and are pretty ugly!

Thanks again.
 
Might be able to get a small USB power meter that could keep it awake.
"Not sure what you mean. Please can you clarify."


There are USB power meters. You plug them in they display current power draw, voltages, communication speeds, etc. It is possible one of these also has a keep alive signal that it can pass to a power bank.

There are also specialty USB battery testers that will force a discharge and measure the battery capacity, but that is not really what you would be looking for.
 
There are USB power meters. You plug them in they display current power draw, voltages, communication speeds, etc. It is possible one of these also has a keep alive signal that it can pass to a power bank.
I see what you mean. However, they look pretty small, so wouldn't they have the same problem of not drawing enough power to keep the unit alive?

Just occurred to me that if he added something else that does draw enough power (say a bigger bulb), and hid that inside the cupboard, then as long as all three bulbs were on the same power cable, when he switched them all on, there would be enough power drawn to wake up the UPS.

Does that make sense? If so, do you have any idea how much power needs to be drawn to wake a UPS up?

Thanks again