Thread: Power from White Plug to Anderson Plug

I think sometimes you need to be a little thick skinned when posting on forums. What works for some will not be accepted by others.

Exploroz is the perfect example of this. A huge number of negative comments on a continual basis.

This forum has few disagreements as we all generally drive a very similar bus, and have very similar ideals.

All of us research and take advice as we see appropriate.

Brett....

Hi and thanks SBD4 and alpick and I did come on a tad strong but I have had a gut full of the mistruths and in some cases, the out and out lies that are being used to peddle DC/DC devices.

Around 4 years ago I was offered the import rights for a USA made 40 DC/DC unit and not just any an ordinary unit.

This one worked out cheaper than the those available now and the USA unit could be set up as a single 40 amp output or as two separate 20 amp outputs.

I did a fair bit of testing with this unit and I just could not justify the price the customers would be paying, for the little benefit it offered, where there was an actual benefit.

I now read all the advertising hype being put out by a number of companies selling these things and I can not believe they can get away with some of the claims being made and if you look overseas, no such claims are made, and this is because most modern countries have REAL consumer protection laws in place to stop this type adverting.

Add to this that I am a sponsor on this site and you can get an idea of how I feel every time I see these mistruths being posted up and I have to try to compete with it.

And note, I don’t hold people discotiwnturbo or muddy responsible. They have simply posted up what they have been lead to believe is the best way to do what they are after, but unfortunately for them, their calculations are based of deliberately misleading advertising.

Here are a couple of charts based on how my gear compares with what is available and these charts are based years of testing, so they are pretty close to the mark.

I hear of owners using the 12S for 12v supply to trailer/van
Personally I have run a#6 SWG (13mmsq) cable from my deep cycle yellow top battery thru a 100amp resetable fuse block to a SD 50 Anderson plug bolted under rear guard. This feds a 50 amp DC -DC charger for the 360aH batteries 3x120 aH full river AGM on the RV van. The 12 S socket is fused for only 30 Amp pin 4 (constant) & 6 (ignition)

The Van uses a 12 pin flat plug as per latest ADR's . GOE mentions an adaptor that uses both the 12N and 12S sockets. AULRO forum has a diagram how this works - see Jayco 12 pin to D4 connection 4 Aug 2012

Rosco

Hi Rosco and don’t take this as some sort of personal attack ( as someone else did earlier in this thread ) but that is a really dangerous set up.

6B&S ( 6 Gauge ) cable has a continuos maximum current rate of 100 amps.

While on the other hand, a 100 amp fuse or circuit breaker is rated at being able to carry 100 amps for 4 hours, but to achieve this it must carry much higher currents for shorter periods of time.

It must be able to carry around 135% of it’s marked rate for 30 minutes and much higher for shorter periods than this.

Even at 135 amps, you are exceeding the safe current rating of the cable, which is set to a tolerance of 100 amp and the cable not exceeding 70 degrees C.

So you have the potential of getting to a point where the cable is running way too hot but your safety device in not caused to trip.

The largest fuse/circuit rating size that can be safely used will 6B&S cable is 60 amps

Next, your 50 amp DC/DC device could draw as much as 75 amps in a low voltage situation and your have a 50 amp Anderson plug in the circuit.

BTW I do not know the brand of DC/DC device you have but some of the lower quality ( less efficient ) devices will pull even higher currents.

A 50 amp Anderson plug, like circuit breakers and fuses, can handle much higher currents for a short time but not a continuos 75 amp load.

When setting up a high current system, you need to cater for the lowest common denominator as being the ruling factor for the rest of the circuit.

In your case, the DC/DC device is the ruling factor but your 50 amp Anderson plugs are the lowest common denominator.

I would suggest you do some safety modifications.

Originally Posted by Muddy Diver

Sorry Tombie but I also meant to say in my last post that I was at pains to point out that the 25A charger would be connected to the 30Amp circuit not the 15A Ignition Positive. Sorry If I didn't mention this clearly enough earlier.

I have found an error in the manual for the LR4. Mine states that the permanent 12V Positive (battery feed) at the 12s socket is 30A (hence my 25A charger should be well matched). When I blew my first fuse I discovered that a 15A fuse was fitted and that the fuse "map" on the back of the fusebox cover states that it was 15A. I have been to Landrover to check whether the wiring is rated at 15A or 30A (if 30A I could refuse to 30A) but they have confirmed that it wired to 15A only). So like many others I am forced to run some cable and fit an Anderson plug in order to power my charger.


Just wanted to post an update to correct my original comment.

Hi Muddy and this may not be so easy to do but there is a FRIDGE circuit on the S12 plug ( PIN 6, RED wire ) and while it is set up to turn on and off with the ignition, it might be a simple job to convert this to a continual connection, like Pin 4, the Green wire.

If it is a straight forward job, you can then use both pins, in parallel to charge the battery.

Also, pin 2 use to be the charge circuit but I am not sure it even has a wire connected to it any more. If it does, this could be another option, either of which will save you having to run a complete new cable.

just to confuse things then.. as a total ignoramus, i have decided not to fit a 2nd battery, the camper trailer i have hired for Cape York already has a deep cycle battery fitted for the fridge, so was informed that i should fit an anderson plug and directly charge from the alternator with an Isolator to protect my own battery from draining, do not shoot the messenger would that be about right ?

Interesting read. I've decided that I'm going to replace the white plug with a 12 pin to tow a jayco camper and 'power' the fridge (with battery in the camper). With hopping between powered van sites, I think this will be the easiest solution.
When I get more serious with heading away from the powered sites, I will get a dual battery set up and an Anderson plug with associated wire upgrades.