12V powered 24/7 capable PC?

'ello! I'm not sure if this fits best here or under the hardware hacking forum, but in any case... I'm building a remote operated observatory. So that's pretty cool in and of itself... But it needs a computer to tie all the bits together.

So the problem is, amateur (and professional) astronomical equipment is 12v powered, more or less exclusively. This makes it really practical to use solar power and a marine battery (or similar) to power an entire observatory, cameras, heaters, coolers, computerized mounts, dome shutter, all of it. But I also need a computer in there to function as a server more or less. It's doesn't need to be particularly powerful at all, most of the communication with equipment is just simple serial comms, with the exception of the cameras which do larger transfers over USB/USB2, and it also needs to run a light web server since that's the way you connect to and use the observatory. Something like a ZOTAC Zbox, or even an Intel NUC, can do the job here, I've also looked at building something myself, but it tends to get a lot more expensive, since we don't have access to their OEM prices. If you got a better idea please share - looking for options!

But I guess the main point I'm getting at is, how do I make a PC run off of a marine battery? There's a few things to consider, one being power consumption (using a DC-AC converter is pretty wasteful) since the battery is exclusively charged by solar power, and the other is the fact that the supply is variable, it's rarely if ever going to be a nice 12 volts. It'll be anywhere between 14 and like 10 volts depending on the battery charge. This is all fine with the astro equipment, it was all engineered for this... Not so sure about your typical PC.

And it needs to not draw huge amounts of power either. The battery I have slated for use in the observatory atm is 110 amp hours, plenty for a night of observing, but it needs to be able to catch up again during daytime. The solar panel isn't huge, I don't remember the wattage offhand, but I'm worried a continuous 24/7/365 load of a typical computer might slowly outpace the solar charge, considering solar time per day, and also accounting for bad weather days, and the big draw during observing nights (Something like 10-15 amps won't be unheard of).

Should I be looking for a 12v capable system, or am I more likely looking at building something to power a non-12v system? This is a little bit outside of my know-how, so hoping maybe some clever people here has any bright ideas or experiences with similar things. I've seen ATX boards that are straight 12v capable, but they're not cheap, nor small, nor very efficient for this particular scenario, I don't intend to run a Xeon rig for this....


So, anybody?

Cheap pure sine wave inverter, a small UPS and some more deep cycle batteries will fit the bill. A NUC would be perfect.

There is even the option of a tablet (if it will run what you need), with which you can easy have run off a even a single deep cycle battery for a very long time. This would be the cheapest as you pick up 12v to 5v usb outlets for next to nothing, then have a single panel > maybe 110w charge the deep cycle battery. Be sure though to get a charge controller otherwise you can damage the battery/s.

Not sure how sunny it is there in norway, but spend good money on good, efficient batteries. Even setting up a 12v array of big 6v batteries will be worth it... more amp hrs of juice.

Hope this helps.

Raspberry pi? Or other arm equivalent? 

There are DC/DC converters that offer atx connectors from 12v lead acid. 


Also super cheap dells have a new 12v only design. Motherboards have only ab12v input and use a voltage pump to do all other voltages. These are for i3/i5 has well mainly. 

Rasp pi is maybe a good choice if you only need a bit of CPU.