Right Tinus, however, I will definately not use the rear battery alone to power the winch. It will always be in parrallel to the main battery and with engine running. I therefore dont think it will ever pull more than around 100amp from the rear, but would like to test that theory if I can find a suitable amp meter. Same for starting, if main is too weak to start engine, the wires from the rear battery is basically same as a jump cable., and this 25mm2 looks more capable than the average jump lead.
I have done some interesting tests – “… om the meet is om te weet...! ”
I have tested this by shutting off fuel pump and then run the starter through the 5m cable for approx 20 seconds (in cycles of 5 second on 5 seconds off – this more than enough – my 4,8 always starts in a split second anyway), and there is no noticeable temp rise on the cable at all.
I have done a similar test with the winch. Both batteries connected and run the winch under heavy load for approx same time it takes to load by boat – again, no perceptible rise in temp in the wire.
The reason why I was thinking of using the second battery in parallel is that after a couple of days winching the boat onto the trailer, the main battery losses most of its capacity as my vehicle and boat stay on the beach and I do not drive around enough to recharge the battery and there is no external power available – my thinking is that the battery power will last twice as long by using 2 batteries, and seeing I have a second battery, why not use it in this way.
I was also re-thinking the routing of the wiring – best is to go through the firewall I think, than through the floor (water leaks etc), but I will have to find a way to make a new hole in fire wall and use a suitable grommet – any ideas there?
I have another idea which I want to try as well - is to place a relay (one from my old winch control box) in the +pos line of the second battery. The re;ay will be activated by the starter motor relay and the winch relay - in this way the second battery will always be isolated unless starting the car or running the winch. Of course this set-up will only be used when I am in the boating mode....
If anyone thinks my ideas are suspect please advise or add your comments....
