Swapping crank battery

[KaiKingma]

Hi there
Im wanting to mount my BCDC charger like this

and i've heard its best to mount it as close as possible to your aux battery, but my cranking battery is on the passenger side. Would it be best to just run a thick cable from the Drivers side (aux) battery to the Charger or is it possible to swap the batteries around and have my cranking battery on the Drivers side. what wires would i need to extend or rewire

 

[Steve Wright]

Hi, are the 80 series not a 24volt starting system !

 

[KaiKingma]

I’ve 12v converted the starter

 

[Chris]

Well done. Great modification. I run my CTEK DC2DC charger in the rear load bay wired from the cranking battery. Used correct cable thickness for the distance and never had any issues. Fused of course. I wouldn't worry too much about sighting it right next to the battery. The one in the trailer runs from the same cranking battery and that must be at least 8m away!

Just thinking about what you're saying, are you trying to charge the aux battery with the DC charger? I may have misunderstood thinking you were running a third battery. My Aux battery still runs some of the vehicle functions so just goes through a VS split charger and the battery in the boot runs from the DC2DC. Unless your front batteries are very different then you shouldn't need a DC2DC really.

Problem is your pictures aren't showing so it's hard to follow exactly what you're trying to do. Whatever you're attempting, I wouldn't swap the batteries around. What you'd gain from shortening one you'd lose from lengthening the others.

I separated my batterins in the front and had a stadard wet acid battery for cranking and an AGM for the aux with no DC2DC unit., Big mistake. So I moved the AGM to the rear and put another std battery up front with no DC. Works fine. It's only where the batteries are radically different that you really need to think about DC charging. Or.... of you are dragging a big load from one and not the other. With the third battery being the leisure battery in mine, the front tow are used very similarly. I'll see if I can try and fix your pictures.

 

[Towpack]

OK, so are the batteries connected permanently, in parallel, or are they seperated by some sort of split charge relay, in which case you can charge the batteries seperately with the charger when the engine isn't running. If they are permanently connected together, assuming both batteries are good and in similar condition, it really won't make any difference which battery you connect the charger to. In theory you will get some voltage drop to the opposite battery but in practice it'll be negligible.

 

[Chris]

Agreed.

I only put the VSR split charge between the two front batteries to prevent parasitic drain etc. As I only need 12 to crank, I can effectively give myself a jump start from one to the other if the cranker is dead. That was the primary reason. Just building in more versatility.

But it's not really necessary their a matched pair from the days of 24v cranking.

 

[KaiKingma]

Just keeping it a dual battery setup. what you said about *What you'd gain from shortening one you'd lose from lengthening the others* makes a lot of sense. Im defiantly just going to run a thick cable to the Dc charger from the aux battery, i think moving the starter battery is just unnecessary.

Thanks for the help !!