I received a call back from my contact at Powerstream this afternoon. He tells me that based on my experience with their PST-PB1108
DC-DC converter/charger device, they're considering offering ruggedization as a value-add service on that product. Electrically it's really quite good; it just needs a little mechanical support if it'll be installed in a high-vibration environment. If anybody is interested in such a thing they should contact Powerstream.
Another product he recommended is PST-BC1212-15
, which is a true multi-stage charger rather than a current-limited power supply as PST-PB1108 is.
Today I also called Midnite Solar to inquire about the charge controller idea. I've always had some doubt about it because PV applications are almost (or completely?) universally a step-down operation. They take a solar array with output of something like 17-600 volts and step it down to 14-ish for charging a battery bank. In contrast, this application could need to step up or down. Unfortunately Midnite had a very busy day today; a receptionist took a message from me but I didn't receive a call back yet. Maybe tomorrow.