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How can I convert a device that runs on AC to battery power and how much power will I need? Answered

I'm making a visually accurate Pipboy (basically a wrist mounted computer) from the game Fallout 3 for a costume. I found an item exactly the right size that does what I want it to do, which is to play mp3's while displaying a photo slideshow: a Hannspree photo alarm clock. The only problem is, it plugs into a wall outlet and has no internal battery. I thought I could just wire it to a battery pack but I want to be sure.

The AC adapter that came with it has an input of 100-240V 0.2A and an output of 5V at 1A

How do I convert this thing to be portable and what kind of batteries/voltage do I need to run it for several hours while I'm at a convention?


The device appears to use 5 volts so it will run off batteries. It should be Ok with 3 C cells in series. that will give you 4.5 volts and will provide 1 amp for about a hour and a half. Or as suggested you can go to a larger battery pack and a regulator to reduce the voltage to 5 volts.

thank you for your detailed answer ^^ I'm not sure how to wire everything together, or where to put the voltage regulator or how it works. Due to size constraints of the prop I was hoping to use AAA or AA batteries; would those provide the current I'd need?

.  More than likely, the wall wart is putting out DC, but there is a chance that it is AC.
.  Measure with a multimeter and/or look for a DC symbol* near the output specs.

* ~half-way down the page

yes, the device actually runs on DC. I just don't know how many/what kind of batteries to use to run it, and what else electronics wise I might need to make it work. I'm doing this for a costume prop and I've never messed with electronics before, so I don't have a lot of equipment ^^; Though I had wondered what the little dashed line meant, and now I know ^_^ so thank you!

in the absence of electronic or electrical knowledge I would use 3 C cells this will give you 4.5 volts which should run your device Ok. Make sure the positive and negative are connected the right way round - i.e. the same as the wall wart.

How many hours ? A set of big AA batteries should give you three hours of operation, but you need a regulator too.

at least 6 if not 8 hours. I plan on using it all day at the convention, but maybe turning it off at some point to save battery power if needed. I was also thinking about using rechargeable batteries and having a second charged set ready for if it dies. How would I use/where would I put the voltage regulator?

You really need to measure how much current it takes, using a multimeter, for me to give you a better idea of what you need. Steve