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Rear Dual battery

Posted: 05 Feb 2017 09:08
by biggles
I am planning the dual battery install and I have some questions.

Firstly I am not keen on a rear battery but no place upfront.

One of the most used functions of my old patrol was the battery link for cranking with a flat crank battery!! With a rear battery is that possible? If I used the Ctek dc-dc will i be able to do the link battery thing?

Re: Rear Dual battery

Posted: 05 Feb 2017 09:16
by Tinus lotz
Yes jy kan 'n by-pass insit, battery baie beter agter weens temps ect....gaan jy lead cristal gaan ?

Re: Rear Dual battery

Posted: 05 Feb 2017 10:37
by Rhett
Will you be incorporating it into the drawer system? And are you keeping the middle set of seats in?

As far as batteries go, AGM batteries are very good, you can use them to crank a flat main but not all the time. The nice thing is you can mount them anywhere, they don't have to stand on a level base.

The only downside to having the battery in the rear, as far as I can see, is the voltage drop between the two batteries. Mine has around a 0.1-0.2v difference. (My 2nd battery sits behind the middle row of seats.) Some guys have said they see far worse voltage drops.

Re: Rear Dual battery

Posted: 05 Feb 2017 10:40
by David M
Bat box.jpg
Bat box.jpg (3.87 MiB) Viewed 5885 times
Busy with exactly that. Used marine switch

Re: Rear Dual battery

Posted: 05 Feb 2017 10:48
by Tinus lotz
Nice one Dave... :thumbup: :salute:

Re: Rear Dual battery

Posted: 05 Feb 2017 12:36
by David M
biggles wrote:I am planning the dual battery install and I have some questions.

Firstly I am not keen on a rear battery but no place upfront.

One of the most used functions of my old patrol was the battery link for cranking with a flat crank battery!! With a rear battery is that possible? If I used the Ctek dc-dc will i be able to do the link battery thing?
As per post above but use the thickest cable you can front to back. I used normal battery cable and I think Chris Skinner used even thicker.

Re: Rear Dual battery

Posted: 05 Feb 2017 13:34
by biggles
Thanks guys:) What size cable would you recommend for cranking? And does the switch just change the positive from the in to the out terminal? Am I seeing it right?

I was going to put the battery in as part of the drawer system but realised as the fridge slide will be permanent and the drawer system is made to be taken out and I may still use the fridge without the drawers in I will put the battery behind the fridge slide (part of it).

Re: Rear Dual battery

Posted: 05 Feb 2017 14:43
by Tinus lotz
25mm2 will work great :thumbup:

Re: Rear Dual battery

Posted: 05 Feb 2017 14:51
by David M
biggles wrote:Thanks guys:) What size cable would you recommend for cranking? And does the switch just change the positive from the in to the out terminal? Am I seeing it right?

I was going to put the battery in as part of the drawer system but realised as the fridge slide will be permanent and the drawer system is made to be taken out and I may still use the fridge without the drawers in I will put the battery behind the fridge slide (part of it).
As Tinus says 25 mm2 cabling or you can go even bigger if you want the rear battery to assist with winching.

The switch is between + In and + Out on the C Tek and bridges it so that current can now flow both ways when in the On position. It is normally in the off position but if you want power to the front to start or winch you flip it to on.

Beware that you leave it in the On position you can drain both batteries and the C Tek will also not be doing it's job.

Of course if the C Tek stops working you flip the switch to On and the 2nd battery charges directly from the alternator.

Steve - Is your C Tek the "Dual" ie, solar capability or the normal one?

Re: Rear Dual battery

Posted: 05 Feb 2017 16:56
by biggles
I have not bought anything for this yet. I am in the planning phase, I would probably get the normal Ctek as I have a MPPT solar controller on the panels.