Searchlight kits complete and still in the sealed crate from a military service depot and resold at public auction ranged from about $500-2000. When the military rebuilds them, they are set back to factory spec and the hour meter will read about 1 hour. I got the $2000+ (custom built to spec) alternator directly from a Balmar distributor in trade for a complete searchlight kit. -(The guy mounted his light on a tripod on the back deck of his home overlooking a tall sheer cliff on the WA coast... cool stuff). The alternator in itself was a work of art. I think the batteries were about $150-200 ea (x 6). The 28V charging controller about 400, the link monitor & shunt 200, over 1000 in marine grade switches and wiring, pan tilt 3000-5000 (good luck finding a good used one of this size), mount by the time it was done 1500, and well over 500 hrs of head scratching and fabrication. 3kw class A sine wave marine inverter 1500. You can probably add at least another 1000 in miscellaneous parts and equipment. Then there's the high dollar stuff; engine and hull mods required to turn that big alternator and still run the boat at "fun" speeds... dont ask. 
The idea was to have the largest reasonably trailer-able boat that could provide as much utility as possible so Id want to use it often. Execution of the "Work hard/play harder" theory.
The US military had 4 cylinder gensets that ran 2700 rpm and noisy as hell (opposed flat 4 configuration almost the size of a VW bug engine) that output 28V@100A. I almost bought one of those massive units to hog up the passenger compartment until I finally found a source for custom alternator. There was also a generator and installation kit to mount and power one of these from a jeep, etc., but collectors are unwilling to part with them since they usually still own the jeep, APC or tank they came with. Also, since I didnt operate at constant RPM, I needed an alternator (not generator) and full battery standby when I was below about 1200 rpm. Im not aware of any plug-in commercial DC charging systems (electric forklift charger, etc) that can output 100A @28V that dont require 3 phase 377-440VAC input. I went the "light weight" route on my installation, which still added about 600 lbs of equipment to the boat.
A few thoughts for anyone who read this far: If you get serious, I wouldnt attempt a short-arc unless I could buy at least two complete searchlight kits with all of their accessories. You will need spare parts because NOS military off-the-shelf parts are specialized and very expensive or usually unavailable. Just keep in mind that accidentally illuminating a persons face within 200 meters while in spot mode for only a moment, stands a very good chance of causing permanent eye damage to that person. So judicious forethought of setup, configuration, how and were you will use this, is paramount above all else. Also, these units WILL eventually explode. The VS3 case is billet aluminum and is supposed to contain the explosion, but the blast, shrapnel and shockwave will likely rip outward through the lens and destroy most of the internals. Anything near the front of this thing when it lets lose will probably get fragged in a major way. If the aluminum case or clamps fail during an explosion, then you have a bomb going off in your face, no matter where you might be standing. These lamps are under many more ATM's pressure than your usual short arc tube. No one that I am aware of currently makes a replacement that will fit or work, even with extensive mods. Just improperly handling of a VS3 lamp (and short-arcs in general) while removed from the searchlight can kill you if it explodes... and they do explode. I took extraordinary measures when I removed mine to clean and photograph it when I was seeking replacements to keep on hand. Also for your best information, find a forum where people collect armored military vehicles... not flashlight forums. Speculation and assumption is also very dangerous and can kill you and others near you. Get your facts and know them.
And of course - I will accept no responsibility for any deaths, injuries or destruction of property in the advent that you use any of this information, weather stated or implied. 
