Thread: Running 6b&s to rear anderson plug

Originally Posted by garrycol

I ran the one cable from my battery along the top of the chassis (not inside it) to an anderson plug at the rear. I do not use a DC DC charger and the smart alternator works fine in charging the van battery.

As my cable is connected direct to my starter battery, as i understand it the alternator sees the two batteries in parallel as one battery and provides charge accordingly - irrespective of whether i am right or wrong on that the van battery gets charged fine and there are no issues in the car.

On the basis of my experience i do not see the need for a Dc Dc charger.

Garry

I have the identical setup other than I ran a twin 6b&s and earthed back at the front on the earth point. I always arrive with fully charge camper batteries (200ah). When I arrive I always disconnect the vehicle from the camper so I always have a fully charged vehicle. I don’t have a fridge in the car, but in the camper, hence this simple setup works a treat. Tbh I have a 50amp circuit breaker on that cable so I’m effectively limited to that charge current, peaks aside.

Finally I am mindful that I start my car before connecting the camper when the camper batteries are really low, so I don’t drain the juice from the starter battery before I’ve started the vehicle.

Originally Posted by JAYRO

....

As far as my plans go, I'm not running an aux battery in the car, but rather one in the caravan. ....

So it sounds like you want to give it the ability to charge from the alternator as well as from the solar panels.
Sounds like you're using the DCDC charger more like an MPPT charge controller and probably have unregulated solar panels for the van?

If this is the case, then the only issue I reckon you will have with your intended setup is that the 6B&S cable is going to be far too small if the auxillary battery(s) are back at the van only if you did want to use the over ride feature(blue wire).
Unless you use larger cabling to the van battery(in effect your aux battery), the 6B&S is not going to give any power, and may even make a jump start worse.
I'd leave the blue wire disconnected other than if you simply want the LED feature somewhere in the cabin as a visual aid on whether the SBI12 is active or not.

The other thing that just came to mind was that if you did set up your system in the manner assumed above, with the SBI12 sending power down the 6B&S cable to the rear anderson plug, remember that the SBI12 isn't a smart device, and it really only senses the voltage on the main battery in the car.
So, even if you have nothing connected to the anderson plug(ie. no van, no battery.. nothing!) it will still be active for as long as the main battery is above 12.7volts.
So you'd want to make sure that anderson plug is well isolated.

Originally Posted by AK83

The other thing that just came to mind was that if you did set up your system in the manner assumed above, with the SBI12 sending power down the 6B&S cable to the rear anderson plug, remember that the SBI12 isn't a smart device, and it really only senses the voltage on the main battery in the car.
So, even if you have nothing connected to the anderson plug(ie. no van, no battery.. nothing!) it will still be active for as long as the main battery is above 12.7volts.
So you'd want to make sure that anderson plug is well isolated.

Hmm I might need to double check as I thought the override aux blue wire on the SBI12 would allow it to only work when ignition is on. Connecting blue wire to the +'ve ignition feed ( fuse 6 is a spare activated from ignition) I am going to use a home made "tap in" fuse to make it a smart device... Hope my plan there is correct? Otherwise yes you'd be right.

I also just got in from cabling the 6b&s. It wasn't that bad or hard afterall ( panic first eh) ... a few tips for the next person who wants to run it as I did and others have suggested above the chassis. 1. get a length yellow tongue to pull the cable and flexi conduit through. 2. I used some cable lube 3. Lower the spare tyre before trying to navigate the holes in the tow bar area. I ended up using a large drill bit to widen the exit hole. 4. Lots of cable ties.

Originally Posted by JAYRO

Hmm I might need to double check as I thought the override aux blue wire on the SBI12 would allow it to only work when ignition is on. ....

No!
blue wire is for adding an led for visual confirmation that it's working(active) and wire a switch in parallel to create a manual activating system.
That is:
when the main batt has reached 12.7v the SB always comes on, no matter what you have fitted at the 'aux' end of the system.
It barely even knows that there is an 'aux' item there. you could connect almost anything that requires a 12+ volt load. It doesnt' know.
Not 100% sure how it works internally, but it just senses that you have 12.7 volt on the main battery and that's really about it.

with the blue wire, only thing it does is that when the main battery is below 12.7v, is that if you ground it(that is touch the blue wire to ground .. which is what a switch will do) .. it then manually activates the SBI12 where it otherwise isnt' active. .. ie. the jump start feature.
The idea of it is, if you had an aux battery in the car(or even the caravan) .. the blue wires forces the SBI12 to connect the otherwise unconnected batteries and it gives you a jump start ability where you don't need to get out and use jumper cables.

Works good too if your starter battery has issues(which they can do).

But don't connect the blue wire to ign on the car. Dunno what may happen ...I'd guess it's protected somehow in the SBI12, but you don't want to find out.
If you want to test it, it's simples just to connect stuff rough and cut to see how it works.
Wire in the main battery, don't start the car. I assume your battery may have settled below 12.7volts.
Make sure you connect the main battery to the main battery terminal on the SBI12. it's quite easy to attach it to the aux terminal, so be 100% sure.
brown wire goes to ground/earth.
Then you see that the blue wire has a spade terminal with a very long protective plastic sleeve.
If you have connected the batt to it's spot on the SB and the brown wire to ground, the SB is is now 'working'.
If you start the car to get the main batt charging, the red light on the SB will come on.
But! before you do this, if you ground the blue spade terminal to earth, you will hear the clunk of the solenoid contact coming on, and the red light come on. I think it stays on for about 8 sec or so and will automagically turn back off again.. ie push button jump starting.

The idea is, if your battery drops down to say 10v or so, and it won't start the car, you push the switch and it then connects the aux battery, you 'supposedly' start the car .. off you go .. to the battery store.
!! doesn't always work tho.
I have 1B&S cable from SB to both batteries, both in engine bay.
Early this year, I had my start battery drop a cell. batt showing 10.9v, but on start dropped well below that.
Tried to use the push start feature but didn't work(well it did work, but not help!)
Reason: main batter deadder than a dodo. 1B&S is good for well over 400 amps! problem is, that the SBI12 is only 80amp capable, so will only allow 80amps through that 400 amp capable wire.
All I did was attach a nice strong jumper cable from aux positive to main positive terminal(remember they're both grounded) and off I went .. to the battery store .. to get stuffed around!(long story .. my bad).

it does work tho. Over winter when really cold(freezing) this stupid Century I have as my main doesn't have the juice to give me preheat and start the engine 'quickly'. So over winter I use the blue wire feature quite a lot

If I were doing what you want to do, I'd not connect the SBI12 at all. I'd be inclined to add a manual solenoid which gives you manual control over whether the rear anderson plug is powered or not. Even a simple thing like a 80-100Amp trip fuse, that you can manually trip yourself to turn off, and then reset when you have the van attached.
But if you do really want to add the SB, then I reckon you'd still be wise to add an auto tripping fuse(with manual override.. ie. just a test button) .. ie. to the aux terminal on the SB to the cabling to the anderson plug.
You can get them from ebay or jaycar or wherever ...

I found it too hard to run the 6B&S through the interior of my D4 and ended up going via the chassis to the rear tow point, but added a separate 8B&S run through the car for the rear cargo area.

Hi Arthur and not sure where you are getting your info from but the SBI12 turns on at 13.2v and turns off at 12.7v

Next, it is a 100 amp continuos rated solenoid, not 80.

6B&S cable is the perfect size cable for charging banks of batteries in a caravan or camper trailer. I have measured 60+ amps going into low house batteries from a D4.

You are wasting your time if you think you can jump start a vehicle, any vehicle, with a low or flat cranking battery, using house batteries as the assist. NOT going to happen.

Furthermore, something most people are unaware of, if your cranking battery has dropped a cell, you can not jump start from another battery, even if the battery is next to your cranking battery. You will need to jump start from another vehicle, with it’s motor running.

Originally Posted by Disco4Dave

I found it too hard to run the 6B&S through the interior of my D4 and ended up going via the chassis to the rear tow point, but added a separate 8B&S run through the car for the rear cargo area.

Hi Dave, the D3 and D4 are the easiest vehicle I have ever come across to run twin 6B&S cabling through.

If you run cabling of any form along or through the chassis, you must make sure you know they are not going to do any body-off servicing or you are going to have to replace the damaged cabling when you get your D4 back.