My Duel Battery Setup(with Charging system modifications)

I've finally wired mine up. (No second battery yet but will be getting a 90Ah AGM.) It's pretty much bog standard according to GoJeeps write up but I've made an insulated fuse post out of a bread board (blue bit) to provide a 100A mega fuse protected circuit attached directly to the Redarc isolater which is just mounted on the bracket that holds the coolant overflow. So the cables in the cabin aren't live all the time I have short cable that joins the fuse to the battery terminal, which I remove and keep in the glove box. There is a small blue wire on the isolater which is for connecting to a momentary switch to overide the solenoid and do an "emergency" start. One day.

I do have a question for yooz though. Each terminal had 2 leads coming out before I cut them off and put on the new terminals. One +ve to the fuse/distribution box and one -ve to the body earth. The other cables must be the +ve and -ve supply to the starter.
Are these cables split anywhere before they get to the starter? They're a touch short since cutting them and they're a bit tired and rigid as well. I thought I might replace them one day as long as they don't get split mid-stream somewhere. Any ideas?

[bobmac]

Hi, for whats its worth, I built myself a sports car a few years back & mounted the battery in a sealed box in a storage compartment behind the seats. I ran a 1/4" nylon tube from the top of the box , through the floor & into (hopefully) the air stream under the car, cut the end of the tube at about a 45 deg. angle , so it acts as a type of venturi, must have been lucky & hit the airstream, as I did not get any acid smells or leakage, & this was a normal wet battery.
bobmac.

[junglejuice]

dsmit, to save me reinventing the wheel where abouts did you break into the wiring harness to do the diode mod? I am about to do mine and I thought it would save me some time....

[Simon R]

Just put in a protecta 100 dual battery system, simple to install and cost $164 (special), when opening the box I found the more expensive 150 unit, not much advantage though, it should help on the jumpstart function. I used a 100AH Allrounder Super Charge Deep Cycle Battery in the cargo area, was concerned about fumes so phoned the help line (1300 737 244) & was advised; This battery is OK to use in non-vented spaces as it does not vent at all when charging at below 14.75 volts - Do not discharge them much below 50% as it then becomes hard to re-charge over 75% on a car charging system, best to then recharge with a 4 stage 10amp mains charger when you get the chance. Stated that the Allrounder is not a fully sealed unit but will not spill unless left on its side for a while. Also said that the AGM Batteries are the bee’s knees but are very expensive, best not to use Gel Cells as they don't charge properly on a car system.

[junglejuice]

I use a 120a/h Agm in the back of mine and it is removable which is ideal for us....

[junglejuice]

Originally Posted by dsmit376

With the green wire containing the current alternator running voltage cut the wire and solder inline a diode with a rating of 6A or more(never gets over 4.5amp current)with the anode pointing at the alternator so that current flows(if you have this the wrong way there will be no alternator output at all but you won't damage anything)

The diode induces a .25v drop(due to the diode I used) in the circuit and the PCM thinks the car really has only has 13.25v and increases the output to bring up the voltage to which it thinks is 13.5v. I suppose you could string a few together and adjust the voltage higher this way but as the PCM is quite smart I did not want to severely place the system way off its built in duty cycle voltage maps.

Yes I know this is an old thread but just in case anybody is doing a search and comes across this thread, the diode in the field wiring trick does NOT work!!!

[del97td]

just another 2 cents, do not use the 10.5 volt low voltage cut off on the waeco it will kill your battery quicker than the taliban can make a ied . all 12 volt batteries are considered flat at 11.0 volts and running them to this voltage will seriously reduce the number of cycles you will get from it.
just google state of charge
12.6 or higher=100%
12.4 = 75%
12.2 = 50%
12.0 = 25%
11.0 = 0 %
i use an abr sidewinder dual battery system cheap, works great, surge protected and has the abbility to link both batteries if needed. my waeco is set to med 11.5 volt cut off. and projectors power pack is also set to shut itself down at 11.0 volts when under load which equates to about 11.25volts when the load is removed to prevent battery death.