As you all know (or not, whatever), I am sharing files between all of my computers using a Linksys NSLU2, running OpenSlug.

Recently, however, I had a few problems because the power connection in my apartment was a little unstable. My whole town seems to have a very fuzzy connection, so power outages of a few seconds happen maybe once or twice a months, resetting all non-battery clocks. Until now, I just restarted the Slug, re-mounted everything in the Slug and on the clients, and it worked again until the next outage a few weeks later.

Lately, it turned into a bigger problem: The power did not go off all the way, but it flickered sometimes (read: daily), killing the poor Slug. Every bigger appliance (including “real” computers) didn’t have a problem with that, however the Slug couldn’t handle it.

So I asked for suggestions on the mailinglist, and Chacko came up with the idea to connect a few rechargable batteries across the output of the power supply, providing the slug with at least a few minutes of battery backup in case the power goes out, depending on the power consumption of the attached devices etc.

Let’s build a custom UPS for the NSLU2!

I made a small sketch of how it is supposed to look like:

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