Another update on the development of the obs...
A few months ago I fried my big jump starter pack, which I used to use to power my laptop. That pushed me to put power on the obs to run the lappy and anything else that needs it. That's been a great move since I now have an iPod docking station so can play as much music as I like while I'm observing.
A couple of weeks ago, I had a few dumb moments in succession resulting in me cooking my other jump starter pack - the one I used to power my dew heaters. So I bit the bullet and installed a deep cycle battery to run the scope and dew heaters.
The battery is a 100AH sealed AGM deep cycle battery (it's something like 96 AH C10, or 108 AH C100). It sits in a new battery box down the back of the power bay (behind the power tank in one of the attached photos). I also made up a power box that includes 3 car cigarette lighter sockets, a battery voltage guage (and momentary action push button) and fuse.
Everything in the power box is recycled from the 2 dead jump start packs, except for the box itself and a BP connector and a few screws.
I had a solar battery charger laying around doing nothing so that now provides a trickle charge to the battery (600mA), and I bought a new fully automatic battery charger to maintain the new battery. It is current selectable (2A, 4A or 6A) so depending on how much I've used the battery I can select an appropriate charge rate taking into account when I plan to get back to it to disconnect. I modified the leads on the battery charger so I can use a cigarette lighter plug to charge through the power box (and I can still attach the battery clamps if I want to use it on other batteries).
The solar battery charger leads were thin enough to run over the wall between 2 of the dome support wheels, and fit down the gap between two of the wall panels. A full solar cell would require much heavier cables and either drilling holes through the walls or a conduit in the floor (which is a bit late now
).
First light for the new power suystem should be tonight!
Al.