toroidalcore

Several components of my home network run off of low voltage DC, 12 or 24 volts. The computer I'm using as my router is one example – it's a fanless industrial PC that actually takes I think 10-32 VDC. I have it running from a 24 VDC power supply.

My small off-grid #solar power system gets used for things like charging batteries and occasionally running my laptop. I make an effort to use it, and not just let the battery float, but I've been thinking about how to divert some of the excess power.

One idea I had was to use a small DC-DC converter, going from 12 VDC (from the battery) up to 24 VDC, diode OR'd with the power supply running my router. It would basically look at the input voltage, and push current up to the 24 VDC side such that the battery didn't sink below 14 VDC (or some other setpoint). The idea being that when the battery is in absorb, you can skim excess power off the top.

This is interesting because another option would be a grid-tie inverter. In my case, I'd need to find a small one that could officially work off of a battery. There are plenty of cheap ones available, but I'm not sure they're approved for this application, and I'm not sure how much I trust them in general.

The converter should be relatively safe if done right, and doesn't interface directly with the grid. The computer I'm thinking of draws 20-30 watts continuous, and while it won't consume all my excess power it can take some and do something somewhat useful – I will admit that a lot of the time it just idles.

Find me at @toroidalcore@hackers.town