Twin batteries in a Landcruiser - help please!
Discussion
My LC has two and one of them is pretty unwell and I thought I'd change both together as I'm going to keep it for a while.
The obvious tactic is to disconnect both the old ones and put in the new ones. But here I thought I could try and be clever - if I replaced one first and then the other then the car would have power throughout and I wouldn't have to reset the clock, radio etc.
Two things bother me here: The local Toyota dealer says the batteries are used in series to generate 24V for starting - although when I look under the bonnet the +ve terminals of the batteries are wired together, which would contradict this. The other thing is if they ARE in parallel, if I put in a healthy new battery next to a dying one is there going to be a huge current flow between them that could be messy?
Your advice would be much appreciated (I'm getting tired of sticking the thing on a battery charger at night!)
The obvious tactic is to disconnect both the old ones and put in the new ones. But here I thought I could try and be clever - if I replaced one first and then the other then the car would have power throughout and I wouldn't have to reset the clock, radio etc.
Two things bother me here: The local Toyota dealer says the batteries are used in series to generate 24V for starting - although when I look under the bonnet the +ve terminals of the batteries are wired together, which would contradict this. The other thing is if they ARE in parallel, if I put in a healthy new battery next to a dying one is there going to be a huge current flow between them that could be messy?
Your advice would be much appreciated (I'm getting tired of sticking the thing on a battery charger at night!)
Edited by FamilyGuy on Tuesday 1st September 08:12
I may just replace them both together as you say and worry about sorting the radio afterwards.Many thanks, exactly the advice I was looking for! Mines a 120 D4-D but everything you say sounds as if it's right for this LC too. I'll bite the bullet and change both together. I too was amazed by the Toyota dealership being about 30GBP cheaper for each of the two batteries than anywhere else!
To continue the saga - I took some photos. I'm still not understanding the 24V batteries in series to start thing because there is a big solid wire between the two positive terminals which would preclude the positive of battery A to the negative of battery B that's required for 24V. Looks like they are hard-wired for 12V parallel operation?
ETA: All the yellow stuff is what happens if you drive across a field of buttercups...
ETA: All the yellow stuff is what happens if you drive across a field of buttercups...
Edited by FamilyGuy on Tuesday 1st September 18:31
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