LX90 + car battery

I'll be placing my LX90 in the backyard observatory semi permanently. I
wont have house current to power the scope and storing C cell batteries in
there wont work for random and sparatic viewing. So I was thinking of
buying a car/boat battery and running it off of that with intentions of
going to a solar powered charging system during the winter/spring. What I
need to know is what battery to get?

I need to power the Autostar controller, a dew zapper, and a small watt
bulb. I'll get the zapper and the bulb information at a latter date so in
the meantime, what am I looking at (watt/amps/ect) for the autostar
controller alone?

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Michael A. Barlow
Lat: 42:57:13.799N
Lon: 77:13:29.039W