'M Thanks for your feedback guys. I'm leaning towards the cheapie 900amp version of the super cheap auto jump starter. From what I've read it should give me more than 4 hours of juice and if it comes with a charger, its a pretty good deal. As I am likely to stick with lenses rather than a telescope, I'm not sure if dew is an issue for me. Will have to find that out - if so, I guess I can get a larger battery to power a dew heater or hair dryer as necessary. Maybe rubber banding some of those pocket hand warmers may be a cheap option too
