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The best evidence so far (including the rather clever Meade test of just leaving the scope in demo mode) is that with a fair amount of slewing going on, the 8 AA alkaline batteries only last about 4 or 5 hours.  While other types of batteries (NiCad, LI) might last longer, there is nothing like a big lead acid battery to keep your scope humming all night.  In fact, if you have dew heaters, it is practically required (or you have to run off of your car).  After extensive web searching turned up nothing I found my pack at Sam's Club for $50.  It is called the "Jumper 1000", made by Century Mfg., and features:

• 17 amp-hour sealed lead acid battery
• 2 cigarette lighter jacks
• 20 amp automatic reset circuit breaker on the cigarette lighter jacks
• Unfused jumper cables
• 3 level charge indicator with "charging" and "charged" lights
• AC charger (charging it is slow - about 12 to 16 hours if completely dead)
• 10" x 10" x 3", 18lbs

  This picture shows the basic unit:

On the front panel is a red "test" button that causes the 3 charge level lights to light (depending on charge).  Here is the inside:

Very neat and clean, high quality wiring through out.  Here is a detail of the wiring:

A couple changes I would consider making:

• Remove the jumper cables and their pods - I did this.  The cables are bolted directly to the battery and would easily unbolt.  The pods can be easily removed when you open the case (leaving to 1/2" holes in the side of the case which I have currently covered with duct tape).  It might be handy to carry this thing around in my car in case I need to jump it but... I have never needed a jump and I have jumper cables already.  The jumper cables aren't fused so if they touched each other - pow!
• I was thinking of adding a power switch and a couple of RCA jacks but I couldn't find any good surface to mount them in.  Right now I have the telescope and dewheater to power and I have two sockets so I am ok.  I actually have a Radio Shack Y-adapter as well, if I ever need to power my laptop via a DC/AC inverter (which I also have).
• Add a volt meter - I would only do this if I find that the cheesy 3 LED system is inadequate.  Radio Shack makes a voltmeter/ammeter module (RSU 11461498) for $25 that could be wired for both (I believe) so you could measure battery voltage or current drain.  Haven't needed this yet though.

February 16, 2002