Ad Astra Observatory

So I picked up a deep cycle battery at Costco. It’s fairly light for its size, which makes me wonder about the plates inside, but 115Ah and pretty cheap, so that’s nice.

I brought it home and tested it. 12.5V, so it’s essentially at full charge.

It has 2 screw posts, which I discovered to be 5/16-18 thread. Since I’m not going to be using this for starting a car, I can forego the 000-gauge wire and do 12-gauge (which is still thick enough that my wire cutters have to think about it a little).

I am putting together a battery box. I want it to become my self-contained mobile telescope power setup. I picture having the charger, the battery, and all the outlets available in one compact package.

I had a great plan of having 2 switches, one for the main power switch, the other to swap between “charging” and “driving the scope”.

The “charging” side was going to have a 3-stage battery charger (which I need to buy — this is the one I want: Jameco #1952409).

The “scope driving” side was going to have a single 12v “cigarette lighter” socket, off of which I would split more 12v sockets to drive the scope, etc. and an inverter to drive anything that absolutely requires AC. It turns out my inverter happens to have a USB-style socket that spits 5v DC also. Win!

After much head scratching, I decided that, since I don’t have the charger yet, I’ll just wait on building out the “function switch” part of the program, and just concentrate on getting the “scope power” side of things working. I wired up a fuse, a main power switch, and the female 12v socket.

It took trips to Radio Shack (switches and fuse holders), Lowe’s (12awg wire), and Napa (wire connectors) to get all the parts. A little more head-scratching and swaging later, I held my breath and waited for sparks or smoke when I hooked it all up.

…

Everything works. Inverter comes on, 12v sockets have power. I’m ready to roll. I’ll pick up a charger at some point, but for now, I have a portable power source that should be sufficient to drive the telescope. Nifty!