Thread: Pragmatic aux battery charging advice please

Originally Posted by TB

There's no fuse that I can see, just the 100A re-settable breaker up at the isolator end.

Resettable breaker is better than a fuse . Fuse trips you throw it away . Breaker trips you reset it .

You can remove the Anderson plug and cable from under the vehicle and reroute it through a firewall grommet to where you need it!

The pins are easy enough to remove from the Anderson plug to allow you to push the pins through the grommet.

Cost $ nil, some sweat equity required.

Originally Posted by slug_burner

You can remove the Anderson plug and cable from under the vehicle and reroute it through a firewall grommet to where you need it!

I very nearly went down that path, but just extending it over and through the tail light grommet is a simpler job and like Scott said leaves the option for a trailer/van connection in place for later.

Originally Posted by TB

Hi all

A previous owner of my D4 installed a Redarc isolator with 100A breaker immediately in front of the cranking battery, with wire to an Andersen plug mounted adjacent to the tow hitch receiver, which I have no use for. I'm about to set off on my first trip longer than 3 days, meaning my 130Ah AGM camp battery is going to require proper charging along the way. I'm leaving in just over a week and need to get something sorted pretty urgently.

My aux battery is in a Projecta Power Hub battery box which has both an Andersen as well as screw terminals for high current use.
I've created a very secure mounting for the battery box on top of a false floor immediately behind the 2nd row seats, right in the centre.
The wire to the trailer hitch Andersen looks chunky to me but I can't tell you what gauge it is.
The wire runs down the passenger side chassis rail to the back of the compressor, then turns across over the top of the chassis toward the driver side before heading rearwards again past the diff to pop out below the bumper to the right of the tow hitch receiver.

Questions:
1. If we're driving for at least several hours most days, can I get away with just charging my aux battery from the alternator via the isolator, or do I really need a DCDC?
2. What's the best option for getting a wire into the loadspace? Extend from the bumper across and through the RHS tail light grommet, or tap in near the air compressor and run (where?) from there?
3. Is there anybody in the Brisbane region I could pay to get this done properly at short notice? I'm getting rear control arms replaced at British Off Road on Monday so depending on the answers to 1 and 2 they might be in a good position to run the wire for me.
4. Any advice on fuse size and location if I'm using an Andersen into the box?

I've actually managed to keep the battery well charged on trips to Moreton etc by connecting it to the rear cig lighter socket, but what I'm reading now about current draw for battery charging suggests that might not be a wise idea, especially for a two week outback tour! Trying to keep it simple though.

Thanks in advance for your thoughts.

TB - like the other guys said. Keep the rear anderson plug as they are brilliant for attaching your compressor with an anderson plug fitted so just piggy back a heavy gauge cable off that and run into the interior panels. You can also then connect a solar panel which will charge your aux battery as you have a circuit loop isolated from the cranking battery. Also grab a couple of bluetooth voltage monitors and you will see you dont need a dc to dc charger as if the cable is heavy enough you will only get 0.1 - 0.3 voltage drop so when the alternator is working at start up it will put in circa 14V into the aux battery and then drops back to about 13.5V which is perfect. I had this set up put in as I didn't want to go under bonnet aux battery as I wanted a 110amp. Bought a 1090mm single heavy duty cargo drawer (which fits snug in the rear on the right hand side), anderson comes out of where the jack is on a fly lead, flea bay battery box with an invertor ($180) which straps to the back end of the drawer, then 40l fridge fits in front AND I can still use one of the third row seats AND get to the wind down jack for the spare AND it can all come out when I am back in town. Hope that helps that you are on the right track.