Thread: Defender 90 dual battery

*that extra piece of metal, turn it up the other way so its a hump, its a wheel chock.

On my D1 that U shaped piece of metal was used to secure the original jack.

Originally Posted by drivesafe

I'm not sure why you are looking for an additional earth.

Because the Defender does NOT have a SMART alternator, you can parallel the negative ( - ) for the auxiliary battery to the negative ( - ) stud/terminal on the cranking battery.

I set it up in 2010 like Tim described and been working without fault since. I have my Traxide isolator earth wire to the aux battery -Ve stud too.

OdinSon, you are over thinking it. Connect cranking +ve to the side of the isolator labelled as cranking. Connect Aux +ve to the side of isolator labelled Aux. Use the same size cable from -ve to -ve posts. Connect the green/yellow earth wire on the isolator to the -ve post of a battery. Tim said earlier that his kit is supplied with the cables. Read the instructions 5 times (great product, poorly described instructions) to choose which setting your want as your default. After that, forget it and let it do its thing.

As for mounting the Aux, you will have to put on your fabricator's hat. Everyone's battery box set up will be slightly different due to orientation of the batteries, height of the batteries, whether you are re-using the OEM tie down method or going to a generic set up etc You can buy battery cradles with mounting hardware or you can ghetto up something with a few bits of angle fixed to the battery box, a few holes in the angle for the common battery tie down with the hook on it and a bit of bar across the top of the battery to hold it down. Alternative ghetto, buy some 6mm threaded rod from Bunnings (cut to length), a length of bar to bridge the battery(ies), a pair of rivnuts into the base of the battery box and a few of nuts to hold it all down.