Dual Batteries in TD 100 series

Submitted: Thursday, Mar 20, 2008 at 16:49
ThreadID: 55749 Views:5224 Replies:11 FollowUps:4
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G'Day all. I couldn't seem to find this in a previous thread so if anyone can point me in the right direction it would be appreciated. I have a 2003 TD 100 series with the standard 2 cranking batteries. As Iam picking up my new Fridge (50L National Luna ) on the weekend I need to sort out my aux. power setup.

Initially I thought it would simply be a matter of changing out one of the batteries to a deep cycle battery(and checking the one cranking Bat has enough grunt), hooking up all the right wires/smart solenoid and running some decent cables to the back etc. However I was having a chat to a guy at the local 4B shop the other week and he tells me that they have gone through a stack of 'issues' with Toyota and as a result they will only ever recommend fitting a 3rd battery rather than using one of the two cranking batteries.

Now as I understand this is due to the TD needing more grunt to kick over in extremely low temps? Is this corrected?

I would be running a Fridge/light and maybe an inverter down the back and couldn't see us parked up for more than 24 hrs. In the foreseable future we will be cruising be in the Pilbara/Kimberly and also back home in Perth.

I Understand that I could get an auto sparky to wire up what ever I want (Unfortunately not all that handy when it comes to the electrical stuff) but need some advise on weather I really need the 2 cranking batteries.

Thanks for any advise/ comments and safe Easter driving

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Reply By: Mainey (wa) - Thursday, Mar 20, 2008 at 18:31

Thursday, Mar 20, 2008 at 18:31
Either Toyota have:
(A) NO clues at all about what batteries are required for the Vehicle


(B) Yes, they do know that 2 x batteries are required for the vehicle

I think it would be (B) !!

Buy a large capacity quality AGM Deep Cycle battery, place it in the back of the vehicle where the fridge can be connected direct to it with appropriate connections.
Connect "battery cables" from (+) & (-) terminals of one Cranking battery direct to new AGM with a $40 ON/OFF SWITCH in-line in the pos (+) cable at a place where it's secure and you can get at it easily.

This will save you money on a quality battery isolator and leave you to manually switch the battery in/out of the charging system.

However, best method is to use a Quality electronic battery isolator instead of 'manual switch' - did I mention fit fusible links @ each end of new cable?

Mainey . . .
AnswerID: 293819

Reply By: Muddie - Thursday, Mar 20, 2008 at 18:45

Thursday, Mar 20, 2008 at 18:45
I had to install a new cranking battery (old one died but I had separated the pair of starters and used the second with my aux to run a fridge etc.) The new battery is a Delkor/Puma 27HR -710cca in N70ZZ and should be able to provide almost as much power as the 2 OEM Toyota starters (which are over kill for Australian conditions, I started my cruiser on a snow trip in -6 deg off the one near dead starter 3 weeks before it failed).
And then I installed a Delkor/Puma 27DC36 Deep Cycle N70ZZ 115 AH to sit in the second front holder and chucked my ARB third battery (Exide Extreme ED4 55 AH), which is only 2/3 size and used the ARB solenoid. The weight in the front end of an IFS 100 needs to be kept as low as possible and the space constraints make it hard to fit a 3rd full size tray for a N70.
This system works fine and several guys on the Lcool forum run it with success.

regards David

AnswerID: 293822

Follow Up By: Richo (SA) - Thursday, Mar 20, 2008 at 19:12

Thursday, Mar 20, 2008 at 19:12
FWIW I have a diesel 200 and this has the same dual factory system.
I have seperated them to one cranking and one accessory battery (still factory batteries) and it works fine. Not that I have tried it in extreme cold mind you but you would never know the difference at this stage.
FollowupID: 559536

Reply By: nowimnumberone - Thursday, Mar 20, 2008 at 18:45

Thursday, Mar 20, 2008 at 18:45
what a load of rubbish
i see plenty of cruisers at work where the second battery is used for the duel on the cruisers
they fitted 2 batterys in the 100s for cold weather starts but its an overseas thing
as you say hook up a solonoid with a good battery and away you go
ps i work at a 4by shop
AnswerID: 293823

Reply By: Crackles - Thursday, Mar 20, 2008 at 18:49

Thursday, Mar 20, 2008 at 18:49
A simple & relatively cheap setup for a TD Cruiser is to leave the batteries connected together and fit a low voltage disconnect switch feeding your assesories. The device is set at a level that will still start the car easily yet run the fridge & lights for around 24 to 36 hours.
To get a longer run time you could upgrade both batteries to something with a combined 200+ amp hour rating. This would give a far greater storage capacity than fitting a smaller 3rd battery and avoids the need for an expensive isolator.
This Arrid model is the sort of device I'm talking about although I can't vouch for this particular models reliability.
Cheers Craig......
AnswerID: 293825

Reply By: Member - David T (SA) - Thursday, Mar 20, 2008 at 19:05

Thursday, Mar 20, 2008 at 19:05
I have replaced both batteries with N70 size (fits without any mods). One is a cranking and the other deep cycle managed with a Rotronics unit. Works perfectly. I agree with "imnumberonenow" that the duel system is not necessary in Australia. The N70 is plenty big enough to crank a 100 series TD even in the snow.
2004 GXL TD Cruiser

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AnswerID: 293831

Follow Up By: Member - Graham H (QLD) - Thursday, Mar 20, 2008 at 19:50

Thursday, Mar 20, 2008 at 19:50
If you are worried about it cranking do this.
Split your batteries as follows remove the connecting positive wire.
Fit your smart isolator. Suggest pass side where there are two bolt holes in inner guard already. Get a battery world or similar to make up 3 cables Two 4 B&S to go from r/h battery to no 2 on the isolator and the other from the l/h battery to no 1 on isolator. The third one is to extend the alternator input over to the l/h battery this can be a lighter cable than the other 2, 6 B&S??
Then if you are worried about enuf cranking you can fit a relay so that when u turn the key to start it hooks both together. Or you can just put a momentery button in the dash and press that when starting. Unless you are in a really cold place you wont really need it anyway.
I replaced both of my originals with Yaesu Hybrids, slighty more capacity than originals. Fitted a redarc isolator from Derek (on here)
FollowupID: 559547

Follow Up By: Member - JohnR (Vic)&Kath - Thursday, Mar 20, 2008 at 22:26

Thursday, Mar 20, 2008 at 22:26
Fitted my Redarc yesterday Graham. I think I will have to upgrade my primary battery soon though as the one I have there takes a couple of seconds that it didn't with two connected. The N70 is the way to go. I haven't got the button connected yet but tomorrow I will :-)) all sweet.
FollowupID: 559607

Reply By: Derek from Affordable Batteries & Radiators - Thursday, Mar 20, 2008 at 22:21

Thursday, Mar 20, 2008 at 22:21
I have done quite a few 'SPLITS' :-)

Fit 2x MRV70 105 a/h 760 cca batteries and a isolator.

2nd option is a battery pack or FLYER in the rear.


AnswerID: 293883

Reply By: geocacher (djcache) - Thursday, Mar 20, 2008 at 22:47

Thursday, Mar 20, 2008 at 22:47
My brother inlaw had his system split by an autoelec in Sth West Vic. No problems on his trip to cape york. No problems when he got back.

Then he moved to the victorian high country to live.

He chewed through a set of batteries, and not all that long after the new ones went in winter rolled around. Suddenly he was bridging the auxilliary back in every morning to start it.

Toyota didn't stick two batteries in it to start it just for the hell of it. If they make a hundred thousand vehicles and can save 42cents a vehicle they'll do it - coming from a OEM engineering background trust me if they could save $100 a vehicle they'd definately do it.

His TD 100 series was converted back to an unsplit system and had no more problems.

Don't split it. Unless you want to fit starting batteries more often, especially if you live somewhere with frosty winters.

AnswerID: 293894

Follow Up By: Member - Tony W (VIC) - Friday, Mar 21, 2008 at 10:59

Friday, Mar 21, 2008 at 10:59
It is simple, split it and use a Redarc or ARB battery isolator that can automatically or manually - depending on how you wire them, connect both batteries for starting ( or winching). I have a switch on mine. It is set for don't connect - off, while starting most of the time then I set it to connect when in really cold conditions. The switch is wired to the starter position so it only connects during starting when in that position. That way you have seperated batteries, ability to have them in parallel whenever you like ( like original) and you still have the space that the 3rd battery would take up for a compressor etc. There is a 200A version of both that take 600A surge current, more than enough to supliement the main battery. Redarc's website has wiring diagrams of the above.
FollowupID: 559670

Reply By: Member - andrew B (Kununurra) - Friday, Mar 21, 2008 at 13:54

Friday, Mar 21, 2008 at 13:54
Just a quick comment, why is one battery good enough in a troopy or ute to start the same motor.....does the wagon have a heap more compression or accessories to drive while starting??

Cheers Andrew

AnswerID: 293973

Reply By: Member - Robert G (WA) - Friday, Mar 21, 2008 at 16:52

Friday, Mar 21, 2008 at 16:52
I split mine using a Redarc solenoid and also fitted a battery monitor at the same time. I have never had any problems with my set up.
AnswerID: 293997

Reply By: The Parts Guy - Friday, Mar 21, 2008 at 18:12

Friday, Mar 21, 2008 at 18:12
Mine was split and then I changed it back and fitted a third battery. I now have peace of mind when camping I cant run the cranking batterys flat no matter how long I run the fridge. I never had a problem with the split though. MMc
AnswerID: 294014

Reply By: Peter H - Thursday, Apr 03, 2008 at 00:59

Thursday, Apr 03, 2008 at 00:59
The ideal place to split is at the RH battery, just place the redarc between the battery and the cable coming from the LH battery. I would recommend new bigger batteries though, I have Optima D31 yellow tops in mine.
AnswerID: 296286

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