OK. Some points I remember about the kit (both good and bad):
1. It limits the charge current to a flat aux batt (<10.5V) to prevent battery damage.
2. It's limited to a max charge current of around 30 amps, and the lead to aux battery must have some resistance in it for feedback to the control circuit.

(not really a problem in a Feroza as the alternator can only supply 55amps anyway)
3. It will not start charging the aux until the main is above 13.5V
4. The internal MOSFETs have diodes that will allow current to flow back into the main battery with the ignition off. Very bad if you leave your headlights on- both batteries will go flat!
4.5. The MOSFETs conducting as above will help boost your main battery when starting.

Also can stop the conduction with the addition of a heavy duty relay (in the aux line) wired up to the ignition if you wanted to.
5. You can modify it to suit your own needs (eg I got rid of the external terminals and ran the wires directly to the circuit board)
6. You will need to bugdet for heavy duty fuse holders for the line from the main battery and line to the aux, they're not included in the kit. Plus some heavy duty wire etc:x
Another point- buy the kit from Dick Smith, rather than Jaycar, as the DS kit comes with a deeper aluminium case which is a lot easier to squeeze everything into.
Anymore questions let me know.
