Electrical system

The electrical system is the most important design aspect of the whole project. From the choice of electrical equipment and battery selection through to cable routing decisions.

Two AC-Delco deep cycle batteries have been used, providing 230Ah at 20h for domestic and some vehicle-related usage. This sensibly leaves the engine battery for solely starting purposes.

The original Ambulance's split charge system was initially utilised. However, while on this trip, the split charge diodes became faulty. It was therefore decided to upgrade the entire charging system.

The charging system now includes a new 95A alternator, a 120A split charge diode unit, and a Balmar MC-612-N regulator (sealed, marine unit). The latter item is the heart of the system, which makes the output of the alternator more suitable for charging deep-cycle batteries. (Standard vehicle alternators have internal regulators which are suited to charging starter batteries.)

Vehicle-related electrical items supplied by the domestic batteries include the front fog lamps and air horn compressor. Domestic electrical users include the inverter, cabin heater (diesel fired), cooker (diesel fired, ceramic hob), fridge, water pump, internal lighting (rear and cab), audio system, ventilation fans, DC power points, reversing camera, reversing lamp, rear spot lamp and AC inverter. The winch is also powered from these batteries to protect the vehicle's starting battery.

The domestic batteries have two main connections to the positive 12V terminals: the winch and the feed to the distribution/fuse/relay panel. Both connections have separate isolators.