Simple/robust dual-battery set-up?

**DeanoH** · 28th November 2012, 07:38 PM

Originally Posted by Samblers

...............................and is this (55Ah) about the largest you can get in without any mods? Was hoping for a little larger ...

Don't let the size (in amp hours) of the (Optima) battery fool you. Whilst they may be smaller in capacity than an equivalent 'normal' lead acid battery they more than make up for it with their charge rate and robustness.

Consider a 'normal' N70 lead acid battery, about 100 ah. When discharged to half capacity it would take at least 8 hours to fully recharge. If discharged to one quarter capacity you would probably need 12 hours to fully recharge.

For a similarly sized Optima (D27M @ 66 ah) the times would be 1 and 2 hours assuming the charging system was capable. The ability to rapidly charge the Optima battery and its resistance to failure from vibration (corrugated roads) more than compensate for its apparent lack of capacity.

If you're a dinosaur like me and hate vehicle electronics and its inherent unreliability with a passion you would have bought a 300 Tdi and installed your old system of alternator fed relay/solenoid coupling of the two batterys. No electronics, reliable and simple, easily understood and simple to diagnose and repair if a problem.

As you've invested in a modern electronic marvel with the Puma, I can only sympathise with your death wish / blind faith in vehicle electronics

. In this case it is no longer a blind leap of faith to trust an 'electronic' battery coupler/controller.

Have no fear, when it all comes crashing down around your ears there will always be a 200/300 Tdi forum member/dinosaur out there to rescue you.

Seriously though, Traxide has a number of products out there that will suit your purpose, set and forget electronic marvels, give him a hoy.

Deano

**Samblers** · 29th November 2012, 12:06 AM

Originally Posted by DeanoH

As you've invested in a modern electronic marvel with the Puma, I can only sympathise with your death wish / blind faith in vehicle electronics

. In this case it is no longer a blind leap of faith to trust an 'electronic' battery coupler/controller.

Ha!

I'm no technophobe but there is an elegance in simplicity*... any 'problem' can be solved by throwing money at it. $500 for a dual battery controller, $240 for a Pirahna battery tray (wow - bent metal), $200 for the battery at least, plus wiring, connectors... may as well buy a generator!

My fridge (Waeco 40L) draws 2A/h average from memory (published figures), though i think our camping experience showed it was less than this. 55Ah gives me a day and a bit i figure, conservative. Down the track i may end up with a camper trailer so can shove additional batteries in that if required.

*Manic - yes the kombi had a poor generator and old/bad batteries. Not bad for 1964 though, and could be fixed with a lollipop stick and a hammer most times

**wannabeexplorer** · 29th November 2012, 06:18 AM

What are your opinions about Redarc?

Battery Isolator & Wiring Kit 12V (SBI12KIT) - REDARC

**harro** · 29th November 2012, 07:23 AM

Originally Posted by Samblers

I’m after some recommendations for a simple dual-battery kit for running a fridge for daytrips/weekend trips plus the odd camp light or two. Not an expedition set-up. There’s lots of dual-battery threads but I’m still a little confused as to what people consider a reliable but ‘no frills’ set-up.

My previous camping vehicle (a VW kombi) had a deep cycle battery which was connected in parallel to the main battery using a $20 fused relay, activated off a 12v signal from the engine generator (dynamo). It was crude, but this is how it seems to be done and served our purposes for many years in UK and Aus. The charging system (engine generator) wasn’t really up to the job though and we had a few trips with less than good charge, the battery eventually died and I vowed to get a better set-up next time…

Now I’m the new owner of a 2010 defender 110 with (I presume) a decent charging system, I plan on installing a deep cycle battery underneath the passenger seat.

I’m seeing installation kits for $100 and anything up to $500 all claiming certain amounts of protection, visual battery monitors, etc. What do people recommend is actually required, and what is a good kit for a basic but robust set-up that can be easily installed by an electrical simpleton (i.e. me)?

Sorry if this has been asked many times before

Sam

Hi Sam,
I run one of these Smart Start SBI 12V 100A (SBI12) - REDARC
A very simple and robust unit, has been in the car for about 5 years now with no problems.
Also a voltage panel meter coming of the aux. battery fitted in the dash so I can see what voltage is in the Aux battery when they are separated by the isolator and also the charging voltage when they are linked (vehicle running).
Simple system and has done us very well for the time it has been installed.

However saying all that I have never seen a negative comment for the Traxide system recommended here and if I didn't already have the Redarc unit I probably would have gone that way.

12 volt Led panel meters are sold on Ebay very cheap with some reading amps as well although I was happy with just volts.

Cheers,
Paul.

**harro** · 29th November 2012, 07:28 AM

Originally Posted by wannabeexplorer

What are your opinions about Redarc?

Battery Isolator & Wiring Kit 12V (SBI12KIT) - REDARC

As said in my previous post, I am very happy with mine.
Although I just purchased the Isolator and got the wiring and terminals separately.

Cheers,
Paul

**Samblers** · 6th December 2012, 03:14 PM

Just ordered a Traxide isolator and an Optima D34 battery … thanks for all the input. Tim was v helpful.

Two further questions:

Best routing for cabling front to back? Presume exit underneath battery tray and run under the body? I will be installing a couple of accessory sockets and an Anderson plug for connecting to camper trailer.

Also what location are people typically using for the accessory sockets in the back of the car?

Cheers, Sam

**Chops** · 7th December 2012, 05:32 AM

Originally Posted by Samblers

Just ordered a Traxide isolator and an Optima D34 battery … thanks for all the input. Tim was v helpful.

Two further questions:

Best routing for cabling front to back? Presume exit underneath battery tray and run under the body? I will be installing a couple of accessory sockets and an Anderson plug for connecting to camper trailer.

Also what location are people typically using for the accessory sockets in the back of the car?

Cheers, Sam

Hopefully won't be too long before I can order mine

Don't forget to post some install pics Sam.

Babs · 7th December 2012, 09:12 PM

Here is mine done, original battery turned sideways allows to fit another the same size, two 90AH

image-588521016.jpg

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**JayBoRover** · 7th December 2012, 10:59 PM

Originally Posted by Babs

Here is mine done, original battery turned sideways allows to fit another the same size, two 90AH

image-588521016.jpg

Sent from my iPhone using Forum Runner

Did you do the instal yourself Babs? Was it a "kit"? Is there a plate that the batteries sit on? What isolator have you used? Too many questions??

Babs · 14th December 2012, 12:04 PM

Originally Posted by JayBoRover

Did you do the instal yourself Babs? Was it a "kit"? Is there a plate that the batteries sit on? What isolator have you used? Too many questions??

No, my mechanic did this mod, the isolator/electrics are Redarc, and he made a custom plate.

I'll get some more pics and info up, soon.

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