We were asked to design a system which would allow the operation of two rooftop air-conditioners while the vehicle was not plugged into a 240v mains supply and while the vehicle is in motion.
With every system like this we always like to have an alternative way of charging the batteries when off grid. Due to the size of the system we increased the alternator power from the standard 150amps to the larger 200amp alternator. This will mean that while the engine is running, we can pull between 150 and 170 amps from the alternator to charge the lithium batteries. This alternator will also be capable of continually running one of the aircons while the vehicle is in motion.
To allow for longer periods off grid we also installed two under slung gas tanks, these had a total capacity 85 litres allowing for extended use between fill ups.