This whole charger cost about $120.  The solar pannel briefcase is $80 at Harbor Freight and the Charge controller is about $35.

The solar pannel has a 12/24 volt slector switch and put out 13watts max on either setting.  The drill battery charger that came with it was only 12v and smoked on the 24v setting. 

The system needed a good charge controller so I was able to locate the one I have posted here.  It is smart and detects a 12 or 24 volt (loaded) solar input and put out 12 or 24v accordingly.  The controller has an 8 amp limit and shuts off when the battery is charged. Very usefull in the military collector hobby for our batteries at 12 and 24 volts.  If you want to order this carge controller, call and order it in person, the shipping will be cheaper because the website defaults to 4 pounds at almost $20.

In the above photo I used it to charge a 12v Dewalt cordless drill battery.  I had it hooked up for about 4 hours and the sky went cloudy after about 1 hour.  When I pulled the battery and tested it I was not able to stop the drill by gripping the chuck with my had for several seconds.  Granted I needed alot longer to charge the battery but I was leaving for the evening so I needed to pack it up.