I'm in love with the $9 C.H.I.P. computers. They're so much fun and so easy to start working with right out of the box! Their tiny footprint and low-cost encourage creative experimentation.
One of the things I've wanted to play around with is creating public wifi nodes and leaving little surprises — benevolent ones — for people that might try to connect to them. That's a different blog post unto itself, but one of the things I needed for this particular idea was a good external batter to run the computer off of.
Another nice things about The C.H.I.P. computer is that it has very modest power requirements, so a quality external battery designed to give charges for smartphones or tablets will likely be more than enough to get at least a few hours.
But I wanted much more than a few hours so I opted for the EasyAcc Monster 20000mAh Power Bank, which is still pretty affordable at $29. The 20,000 mAh (milli-amp-hours) is much more than enough to the C.H.I.P. computer.
In a not particularly scientific test I setup the computer to:
- Connect to my local wifi
- Create its own wifi network
- Run an Apache server
- Write to a log file once per minute with the current timestamp
The reason I did that last step was because I wanted to let the computer run until the battery drained completely and see how long it lated. The end results was about 46.5 hours! Granted, it wasn't really doing much. If I'd run the same script having it ping another website once per minute I would expect that number to dip noticeably, but even half that amount would still be plenty for my needs.
So if you're looking for a cheap computer and battery to make public computer-based, wifi-based art projects — and potentially get into good trouble — I highly recommend the the $9 C.H.I.P. computers and the EasyAcc Monster 20000mAh Power Bank.