I see PowerMax has updated its website and has the charger I have with this set: (mine is as shown above in the photos) I see the "adjustable output" is optional. Not clear if the little voltmeter and the carrying handle are too
http://www.powermaxconverters.com/pmbc.pdfNo idea how you go about getting one or the cost. Randy has a version of the showroom type but his photo is different from these. Boat and RV has something more like it, but again it is hard to figure how to get all the features. Maybe have to talk to somebody at those places.
You can get info from Errin at PowerMax, but they try not to undercut their dealers.