PROJECT 4, Dual battery set-up for a Defender ( & other 4x4s )

G'day Drivesafe

If its any use to your thread I've got some pics here http://www.aulro.com/afvb/showthread.php't=28356 of the physical positioning of the 2nd battery in a fender. Its a 100a FullRiver AGM.

I too faced the gassing issue and decided to seal the box at the top and seal all the entries as best I could with the exception of the drains. My theory is that if the lid has a good seal and all the cable entries are sealed as best you can (thank god for sikaflex) then if your vehicle is in the water for a short period (e.g. river crossing etc) then the trapped air in the box will stop the water rising inside the cavity and your batteries and electronix etc will stay dry.

I'll be watching this thread very closely with a great deal of interest as I've just brought a camper and now have 3 :eek: batteries to charge. I might have a chat to you in the new year about hardware and how to go about this. I'll probably chuck out the stuff I already have in there.

Cheers,

Thanks heaps Adrian, I have had so many Fender owners asking me for info and you have it all there.

I’ve posted the pictures again here but I recommend anyone with a Fender, wanting to get some good info on the layout of the batteries under the seat, go to the link Adrian supplied in the post above this one.

Cheers and thanks again Adrian


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http://i19.photobucket.com/albums/b1...Image0009a.jpg

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You have the earth going across the batteries? that's an interesting way of doing it.

Glad I'm not the only one that has a problem with space, its a pain when pulling terminals on/off

Quote:

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Originally Posted by jsttry

You have the earth going across the batteries? that's an interesting way of doing it.

Glad I'm not the only one that has a problem with space, its a pain when pulling terminals on/off

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Funny you should mention that. I noticed that in Numpties setup too. Its nice and neat. One thing I've just done is modded the strap that keeps the start battery secured. (its now 50mm). When I put the 2nd AGM battery back in I'll turn it round 180 degrees. Reason for this is that it puts both the + terminals above the removable cover. I'll then glue a 4mm sheet of insertion rubber to the bottom. The theory is that if it ever gets turned upside down :o or it gets bounced hard enuff for the terminal to touch the underside of the lid then its insulated.

Quote:

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Originally Posted by jsttry

You have the earth going across the batteries? that's an interesting way of doing it.

Glad I'm not the only one that has a problem with space, its a pain when pulling terminals on/off

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Que! When you say the earth going across the batteries, I assume you are referring to the common earth lead. Why interesting. Seems most logical to me, negating the need for 2 earth to chassis connections. BTW this is how I did the Stage 1 nearly 20 yrs ago and it has never given any bother.

Quote:

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Originally Posted by numpty

Que! When you say the earth going across the batteries, I assume you are referring to the common earth lead. Why interesting. Seems most logical to me, negating the need for 2 earth to chassis connections. BTW this is how I did the Stage 1 nearly 20 yrs ago and it has never given any bother.

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Numpty,

I've done the same. I was going to run an independant earth for the AGM 2nd battery. Then thought WTF for????????????????? :eek:. Its unlikley its ever gonna get 1400 CCA through it. If it does the bloody chassis rail will melt first :D

I just never thought of it and the dual system in the County I brought last year had 2 earths, didn't think otherwise. Will get some pics next time I have the car apart

Quote:

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Originally Posted by jsttry

I just never thought of it and the dual system in the County I brought last year had 2 earths, didn't think otherwise. Will get some pics next time I have the car apart

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I'll come n have a look in 8 weeks when I'm up there. :D:D

PM me when you're on your way and can arrange a trip with the locals from www.darwin4x4.net

Has anyone had any experience fitting dual 6V batteries, wired of course to give 12v output?

I have heard of his being done but am unaware of the reason. Maybe some of you electrical gurus out there could explain the pros and cons of such a system - physical size, capacity etc etc. :confused: