Looks similar to the same type of setup that International uses in the ProStars (Celadon's new trucks have them). The A/C unit is mounted in the passenger-side dog-box and draws power from the batteries when it's running. The truck's have 8 batteries, plus low-battery auto-start protection (if the batteries get too low, the truck starts to charge them).
It worked pretty good, even when sitting in Laredo in the middle of August for days on end (yes, the truck had to start multiple times). If the A/C is running nonstop, figure on 8 hours or so max. But, if the temp isn't an oven, like down there, you can easily go a full 10-12 hours. From the sounds of the setup, it uses it's own dedicated batteries, so you wouldn't have to worry about the starting batteries getting drawn down. When they did get low enough for the truck to need to autostart, it would run for 90-120 minutes or so to recharge.
The International system also uses a bunk heater (not Webasto, but another major brand that I completely forget now).
