Just Imagine has two banks of house batteries and a dedicated engine start battery (see the diagram below). The house batteries are all 6 Volt, 220 Amp Hour, flooded, lead acid, deep cycle Golf Cart batteries which seem to give the most bang for the buck for the size and cost.
Bank one consists of 2 batteries in series for 12V - 220 Amp Hours, and bank 2 consists of 4 batteries in series/parallel for 12V - 440 AH. Bank 2 connects directly to the inverter.
There are two 100A Balmar alternators each with their own smart regulators for total redundancy. One alternator charges bank 2 and the other alternator can be directed to bank 1 or two or both.
The engine start battery is charged through an isolator and a combiner to keep it totally separate. It can be switched to the house batteries if needed.
Howard [ Just Imagine ] 12-Mar-2008