Dual Battery Systems

Hi Tukka

A battery can draw heavy amps in its initial charge so best to use one that can cope. Just as a guide a typical AGM will draw C4 or 25% of its capacity when first connected with a surge of about 50 % on top of that if it was used for cranking or is deeply discharged.

For example. If you have a 120 a/h AGM as your aux battery and it is low on charge or it was just used to run a winch it will draw approx 30 amps from the alternator but the initial charge may be 45 amps or as high as 60 amps in some cases fro the first few mins.

It is important to work this out when fitting your batteries and isolator. There are also factors like wire thickness, temperature and distance that will affect the amps drawn. If you can provide more info we can direct you to the correct selection of parts.

I run dual Century Overlander Cranking Batteries in parallel via a basic $30 solenoid and dash switch. OK, so its not so flash with no bells and whirsles, but it works.

The names you mention have their merits and their cost. I ran a Rotronics(another good brand name) Battery isolator and it lasted 18 months.

A lot of this gear is overpriced finnicky electronics



Cheers

My 05 100 Series GXL TD came from the previous owner (Gov Dept.) with a Surepower controller for the aux battery [ http://www.surepower.com/separator.html ] - very compact and trouble free for my 8 months or so to date - I had a Rotronics controller on my 99 Jackaroo setup for 7 years - totally trouble free too.

I have been running a Piranha DBE150S Electronic Isolator for around 7 years now with absolutely no problems whatsoever.

Whatever brand you choose, ensure it is a "smart" Isolator that keeps the starting battery and any other auxiliary battery(s) electrically isolated. This means a fault in one battery cannot affect the other. A "smart" controller is automatic, ensuring that firstly the starting battery has a sufficient level of charge, then swapping over to charge any auxiliary battery or batteries.
There is no chance of human error (forgetfulness) from compromising its operation.

Bill.

I bought a duel battery set up for my Hilux from Derek two years ago 80 amp I think. 18 months later it failed in station country north east of Smoky Bay.
When i got home I emailed him and even though it was six months out of warranty he replaced it ,no questions asked,with a 120 amp job. I thought that was pretty good of him.

I run two aux battery's the same size and brand as the cranker
because I was told that the alternator will only see the first battery and if the aux was bigger it would only charge to the capacity of the cranking battery.

Could be wrong, only what I was told. If so don't tear strips off me.

Trev.

tukka,
Redarc are the manufacturer and of the 3 you nominate would be a good choice as they are probably most widely used.

I would use an electronic isolator, but that's just my choice.

Mainey . . .

Hiya Tukka

I bought the IBS (TJM) dual batt system with all the bells and wistles (to scared to say how much i paid lol) TJM where the only ones that could put another batt under my bonnet,things had to move to get it in my Hilux..

Now the monitor is on the left side of my steering wheel (you can put anywhere)..I love it actually a constant look at the battery's performance and if ones flat at a push of a button across to the other...(not that i hav had a flat batt touch wood)

IBS

Oh and you will not go wrong with Dereks advice either (Lovely bloke from what i read)

Just a thought for you..

G'day,
I'm also looking at putting one in (my LC 100s T/D which already has twin batteries). My auto electrician has recomended the BI-80 from Electro Parts. Does anyone know how it compares with the other brands? Barry

-allows indepenant starting on each battery to check for problems and subsequent isolation,
-alows independant charging/ discharge
- no electronics to go wrong
- works