Hi all, I'm installing an aux battery.
Wondering how others have routed the cabling from the engine bay to the cargo area.

Cheers MY11 SD4 SE Auto

I have read that you can go via the bonnet release route.

At what rate do you want to charge the auxiliary battery?

I have used the rear power outlet & DC to DC charger which runs up to 18amps. Fuse is 20amps. Typical charging is around 7 to 12amps on my setup.

I replaced the power outlet with an Anderson plug as the electrical connection on the back of the power outlet was dodgy at best.

Victron now have a smart DC to DC charger. https://www.victronenergy.com.au/dc-dc-con...tr%20smart Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

Surely if you just connected the aux battery to the rear power supply the alternator would simply see a larger battery and charge accordingly? After all, that’s how auxiliary batteries on caravans are charged.

Well, the cable to the rear 12v outlet isn't quite the size of the cable from the alternator to the start battery and start battery to ground. 6 B&S cable.

I'm routing it through a VSR so the starter battery isn't discharged when the fridge is running overnight. Been there done that paid the price. MY11 SD4 SE Auto

Indeed, a VSR is the way to go - you wouldn’t want the starter motor drawing current from the aux battery. But that aside, the cabling should be quite sufficient for battery charging purpose. As I said, that’s how caravan batteries are charged.

My setup:

https://www.freel2.com/forum/topic34006.html

A few more photos here:
https://www.freel2.com/forum/topic31435-30.html

& here:
https://www.freel2.com/forum/topic32827.html

I have a fourth battery which sits in the rear foot well when traveling.

Anderson plug in boot:
https://www.freel2.com/forum/topic33954.html

Back corner of the car now:

Click image to enlarge

Click image to enlarge