Anderson plug install on rear bumperusing loop from current 12 pin plug

[JohnZ42]

G’day forum members,

I am hoping some one can steer me in the right direction. We have a pop top van and recently had a 12V dc to dc 20A dual charger installed in the van, as we have had issue charging battery while driving- this was based on advise of a friend: long time caravaner, we have only had van a few years (4) and we have only done short trips longest to Coffs Harbour NSW from Mornington peninsula. Plan to go to WA when we can.

He stated we now need to run a 8awg/bs wire from battery to rear of car and install an Anderson plug to connect the van in when driving. Charger has 8awg/bs.

I need to say I have very little knowledge of electronics, and at 74 y.o. and don’t think I ever will. Our son-in-law was a mechanic but changed professions some years back and became an electrician- not auto. When I told him that the friend stayed that I needed to run a cable from battery etc. to an Anderson on rear bumper.

My S.I.L. stayed no need to run a cable from battery it’s just over complicating things, just run 6mm wire loop from the power pin (#8) on the 12 pin female plug on the car, a 2006 discovery 3 V6 petrol, to an Anderson plug and an earth to car body from Anderson plug, which he can do.

This worries me as we have Electronic Stability Control on van and don’t want to compromise the system on the 12pin and not have the ESC working correctly if we have an issue with the van ie. winds, swaying etc. Number #8 pin is already looped from pin #9.

This seems a short cut to me and also too my neighbour also. Can any one in this forum PLEASE help, don’t want to upset the daughter or S.I.L or more importantly the WIFE.

Apologises for long rumbling intro. Thanks JohnZ42 for all and any help.

[loanrangie]

The discovery will have a white trailer socket (12s) on the left of the tow hitch, if you get the corresponding plug you can make up a short adapter to an anderson plug for the van.
This may help you -

Anderson plug to white trailer socket. (https://www.aulro.com/afvb/l319-discovery-3-and-4-a/224746-anderson-plug-white-trailer-socket.html)

[drivesafe]

Hi John, it’s not a long rumbling intro. The more info supplied about your setup, the easier it is to sort it out.


A question for you, how did you charge the battery in the Pop Top before adding the DC/DC device?

[JohnZ42]

To loanrangie and drivesafe,

Thanks for your replies and also suggestion re white plug. When the van had the ESC installed the installers also looped the flat 12 pin female plug to the reinstalled plug on the right of tow hitch, is the white in any way connected to the one on the right that’s looped to the flat 12 pin?

Re the charging: I’ve always charged the battery regularly whilst at home and fully before a trip, the one time I didn’t fully charge but just to good stage on the battery analyser by the time we got to an hour past the NSW border and stopped for the night (free camping) we had no internal 12V lights.

Fully charged battery before heading for home but had some issue with charging, PSU mustn’t be working probably.
Neighbours advice, not mine. As stated previous I know jacks..t about electrics.

I might bite the bullet and take to an auto electrician to install the Anderson plug. Bugger the family wrath. Bit sceptical about another loop from an existing loop for the loop for the A’son plug.

Once again, thanks for the replies. JohnZ42

P.S. the reason I’m trying to tread softly softly is: that the daughter and s-i-l purchased a 200W folding solar blanket and also dc to dc charger as gift, but we (wife an me) insisted on paying for the install that the s-i-l organised for the dc to dc charger.- JohnZ42.

[drivesafe]

Hi again John, and I assume this is a D3 or D4.

If so, you would be far better off doing the cable run to the rear yourself as it is more like a plumbing job than an electrical.

But if need to get an auto electrician to do the work, make sure they run the new cabling through the disco and not down through the chassis.

If they run the cabling down the chassis, which is very easy to do, but it could workout to be a VERY expensive mistake and repair job for you.

[JohnZ42]

Thanks drivesafe,

It’s a 2006 D3 V6 petrol, but she’s a bit like me: full of crickey joints and groans but still going reasonably well ( like the wife- if I speak to her nicely) with 264k’s on the clock.

I take on board your advise and double check with auto electrician to see if he is going to run through the car or underneath!

mightget the s-I-l to do abit of work ( he’s volunteered to look after the my old-23 y.o. Haines Hunter boat while we’re gone) so he can contribute now!

From what I have read in the last couple of days is that I need to connect to car battery using some 8awg/b&s twin core cable- with a 40/50amp fuse on positive and earth to body of car in suitable position! Going to have to get familiar with all this stuff if we going to travel bit.

If I fail then auto elect. Pity your in Queensland would get you to do it.

Regards and thanks for the input and good advise. John

[drivesafe]

Hi again John, you should run 6B&S ( 13.5mm2) not 8B&S ( 7.9mm2 ) and it is better to run twin from the engine bay all the way to the Anderson plug at the rear.

This will dramatically reduce the voltage drop at the caravan, and if you have lead acid house batteries in the Poptop, and you will not need the DC/DC charger. Your alternator will charge the battery or batteries far quicker.

Also, if you have the slightest handyman skills, you can do the job yourself.

These vehicles are exceptionally easy to work on and this is more like a plumbing job, not an electrical one.

[loanrangie]

Hi again John, you should run 6B&S ( 13.5mm2) not 8B&S ( 7.9mm2 ) and it is better to run twin from the engine bay all the way to the Anderson plug at the rear.

This will dramatically reduce the voltage drop at the caravan, and if you have lead acid house batteries in the Poptop, and you will not need the DC/DC charger. Your alternator will charge the battery or batteries far quicker.

Also, if you have the slightest handyman skills, you can do the job yourself.

These vehicles are exceptionally easy to work on and this is more like a plumbing job, not an electrical one.



Tim would you advise going direct from the main battery even with one of your controllers fitted ?

[drivesafe]

Hi Loanrangie and yes.

By going direct from the cranking battery, ( for the ( + ) positive cabling ), you reduce the chances of unwanted voltage drop.

While using the chassis for the earth return can work, the problem with newer vehicles is that you can not test for any resistance points prior to wiring up a system.

High resistance point will not show up until a high current load is applied and this will slow and even stop an auxiliary or house battery from charging properly.

So it is far safer and makes fault finding a lot easier, if you connect the positive ( + ) cabling directly to the cranking battery’s positive ( + ) terminal.

But the negative ( - ) cabling must NOT be connected to the cranking battery’s negative ( - ) terminal, as this will interfere with the vehicle’s BMS and can cause problems like the vehicle going into Limp Home mode when there is not an actual problem.

There are two earth studs, in the inner guard, just in front of the cranking battery compartment and these are perfect for earthing heavy current carrying cables, including winch cables.

EDIT, You will need either a 50 amp auto resetting circuit breaker or 60 amp fuse, fitted to the positive ( + ) cable, as close as practical to the cranking battery’s positive ( + ) terminal.

[loanrangie]

Even on the D3 without a BMS ? Winch uses one of those earth studs now and i know not to mess with earths that are being used by any of the vehicle systems.

[JohnZ42]

Even on the D3 without a BMS ? Winch uses one of those earth studs now and i know not to mess with earths that are being used by any of the vehicle systems.

Hello to drivesafe and loanrangie,


Thanks for the continued advice and support re my installation question.

I think I should mention products we have: we have Atem Power 200w folding solar blanket an a Atem Power 20A 12v dc to dc battery/isolater capable charger for all batteries including Lithium - as previous mentioned these were gifted to us.

The install (SIL’s mate) on the charger was done with “8awg/b&s wire” as it was recommended by the seller (Sunyee) to my s-I-l, when he checked with them after purchase, so he says.

I’m reasonably handy with som plastering, stud framing and bit of water pipe plumbing- brother and some other family where in the trade, not me, and learned a bit from. “ I presume I can’t use the nail guns to pin to car anywhere”

So I will give it a go, the install the Anderson plug to the car, now that both you gentlemen have given me more info and a bit of confidence.

One question though, if I use 6B&S wire with appropriate fuse will this cause an issue with the charger being on 8awg/b&s?

Also, the installer suggested that we should in the near future, look at replacing the current calcium battery that’s over 6 y.o. with a 125AH Lithium LiFePO4 battery (battery size restrictions in current location). If we do replace with Lithium not being able to get to the PSU to disable the charge wire from PSU to battery will this cause an issue with the Lithium whilst driving.

Once again thank you all have given advise. John

[maxperformance]

I read through this and thought I might share a same story.

I recently fitted exactly a similar setup in a poptop Caravan for one of my customer.

We setup with front Anderson plug to charge through 20a dual battery charger, and another Anderson plug on the side of the caravan for solar charger plug. We also setup behind a 2000W power converter and an array of extra accessories, USB, lights.

It was not working at first then quickly I tested the battery was too old and low. So they changed a new FullRiver 105ah and great ever since.

So if your system does not work, assuming you have 12V+ charging from the car to the caravan either from original port or a direct Anderson plug from the front battery, likely the problem stays at the Dual battery charger unit or your battery.

[drivesafe]

Hi again John, first off, going to lithium batteries can have some advantages, but you have to be very careful when selecting the right lithium battery as there are now heaps of absolutely crap lithium batteries on the market.

Next, what would be the reason you think you need to go to a lithium battery. What advantages do you think you will get?

[JohnZ42]

To maxperformance, thanks for your input and more so let me know we are not the only ones with this type of product. Never heard of Atem Power before receiving the items from family. Refreshing to see how many people in the forum are willing to contribute advise/suggestions.


To drivesafe, I am pleasantly surprise with your patience with my lack of knowledge on the subject and you pushing out questions/suggestions. Please don’t stop

The only reason I brought up the question on Lithium battery was based on the suggestion by the chap (SIL mate) who wired up the van’s charger: it would lighter, a bit smaller in size- we are restricted with space where current battery is set up, and for the size an extra 25amps i.e, 125ah lithium compared to current 100ah calcium battery. There was something else but I can’t recall. He did not recommend one brand to another.

SIL decided to look up Sunyee’s web site, as that where he purchased charger & solar blanket, after mate mentioned Lithium, they have an Atem Power (?) Lithium 125AH battery and smaller in size and weight to current battery. As ours is 6+ y.o. I gave lithium a thought and ran it through the forum?

As with previous post your input is welcomed. Also in previous you suggested using 6B&S wire for Anderson plug on car; would this difference in size to the 8B&S used in van wiring set up be an issue? As previous statement I know jacks..t about auto wiring.

As always any and all input is welcomed include just get on with it and leave every one alone. Regards John

[drivesafe]

Hi again John, this is by far one of the best forums for seeking and getting help, for a whole range of subjects. People just want to help.

If you can, get the specs for the lithium battery you are considering, or post up a part number for the battery and I will source the specs for you.

As I posted, there are some crap lithium batteries on the market right now, and one I saw on another forum, the battery actually had specs that most AGM batteries bettered.

The suggestion to go to 6B&S is to future-proof your setup and there will be no issues with having the larger cable in the tow vehicle, other than it will help your DC/DC device to run more efficiently.

[DiscoMick]

Just supporting what Drivesafe and others have said, we have good cabling with 50amp fuses running to a rear Anderson plug installed by an auto electrician and it works fine.
To properly charge a van battery requires more power than you would put through a normal trailer plug just to trigger lights and brakes.
You mentioned running a 20amp charger. Your alternator can output more than 20amps, which is why the recommendation is 50amp fuses and suitable cable to cope, for a safety margin.
Don't cut corners on charging van batteries. Lithiums charge best at about 14.2 volts, higher than AGMs.
Personally, not being an expert, I get an auto electrician to do the work, just to avoid the chance of causing a fire.
Hope that helps.

[PhilipA]

Can I suggest that you use a 2pin 50amp plug as sold by Supercheap as they have a positive locking mechanism flap like a 7 pin plug.

I have helped a bloke on the GRR where his Anderson plug was ripped out by grass in the centre of a track. I luckily had a spare Anderson I could give him.'

Just today I read on AFAIR Exploroz the same thing happened to someone on that forum.
Andersons are great and I use them a lot but not on the rear bumper.
Regards PhilipA

[Tombie]

Can I suggest that you use a 2pin 50amp plug as sold by Supercheap as they have a positive locking mechanism flap like a 7 pin plug.

I have helped a bloke on the GRR where his Anderson plug was ripped out by grass in the centre of a track. I luckily had a spare Anderson I could give him.'

Just today I read on AFAIR Exploroz the same thing happened to someone on that forum.
Andersons are great and I use them a lot but not on the rear bumper.
Regards PhilipA

Spot on, they need to up tight and away from being caught.