# Battery relocation using OEM parts



## charliec (Dec 8, 2005)

Hi all

Following on from another thread about relocating the battery in a coupe 225 I thought I would post my experience of doing this modification. I've had no running problems (touch wood) and the job took amount 3hrs (a lot of that was fafing around trying to decide what to do).

I relocated my battery to the boot in 10 months ago using ome parts, whilst retaining the jack etc in the spare wheel well. The parts i used where:
V6/QS wiring harness and fuse holder Pt 8N0 971 227 (battery loom) £115.21
V6/QS wiring harness for battery -ve Pt 1J0 971 234B (earth strap)	£6.79
V6/QS Pipe battery breather pipe	Pt 8Z0 941 159C £0.76
V6/QS Cover Cap (battery - terminal cover) Pt 4D0 915 429 £2.03
V6/QS battery I opted for orginal to make sure it had the correct beather hole
VW Passat battery tray for local breakers £5

I also used a V6/QS tool holding foam, because it has the correct cut out for the battery and i used the V6/QS tyre pump and foam.

Below is a description of how I undertook this little project and is no way a guide or recommendation that this should be undertaken, so if you try this and cock it up I'm not to blame (right arse covered)

Before any work I disconnected the battery, applied the hand brake, put in gear and choked the wheels (I could not shut the boot from now on as it has an electrical release)

*Battery fitting*

Using the passat battery tray the battery fits snugly into the rear near side corner of the spare tyre well. The passat battery tray has three mounting points, two that located to the side of the tyre well and one to the bottom, to bolt the tray to the chassis I had to drill three holes. By lowering the rear exhaust back box down on a trolley jack I could remove the exhaust heat shield, i now drilled the hols as required (making sure not to damage any wires pipes ect). To secure the tray to the chassis i used M12 nuts and bolts with thick gage galvanise steel plates (the type used typically when bolt heavy pieces of wood together to spread the load). I bolted through from the outside to the side of the chassis sandwedging the chassis between two plates the tightening down with a nylock nut. All bare metal was given a good coat of hammerite (including metal exposed from drilling) and left to dry. A fourth hole needs to be drilled for the earth strap, I located this by putting the battery in to the approximate final location and using the new earth staple estimated an appropriate location on the rim of the tyre well (I removed the paint from this location to increase the area of contact) .Now I had effectively three studs to which the tray could be secured to, with the tray secured the new battery bolts down in exactly the same as the original battery, I managed to re-use the existing bolt and bracket. Before i forget a small hole needed to be drilled for the battery breather pipe to fit through, to finish this small hole a found in maplins a small rubber grommet doughnut shaped with a grove on the outside, the internal diameter was the same as the diameter of the tube with the external diameter being that of the hole this form a nice tight fit to stop water ingress.

*Battery Loom*

Using the V6/QS wiring harness and fuse holder (the new fuse at the batter + terminal replace the original one, this is so if the fuse blows the battery loom is isolated at source) i routed it along the passagers side behind the boot side trim panel and the rear trim panel (the one that houses the rear speaker) and underneath the carpet to the bulk head. To do this i had to remove the passenger's seat and the glove box (Waks web site as ever is a great resource and give guidance on how to remove most peices of trim). I routed the cable along the floor plan instead of locating it adjacent to the cable tray next to the door seal, because when the carpet is put back there is a nasty lump all the way along the seal where the cable runs. On the batter loom there is a rubber grommet, this is intended to be used where the looms exists the chassis. Audis location for this is under the passenger's seat and the loom runs externally under the floor plan, this is another point where the floor pan differs on the standard chassis as there is no hole in this location (on my chassis anyway). Therefore I ran the loom up to the bulk head, where behind the heater I found a blanking rubber grommet, from the engine bay side this is just behind the plastic cable that runs from the battery to the area adjacent the nearside suspension top mount. I cut a small hole in the grommet and pushed the cable through (this was a bit difficult at first) with enough cable push though to grab hold of, i pulled the rest of the cable through from the engine bay side. I routed the cable in the existing cable tray up to the existing fuse box (mounted on top of the existing battery) with the existing battery removed i also removed the loom that connects the battery to the starter motor. The new looms has two ends one connects to the starter motor and one to the fuse box. On the fused box there is a spare way on the right hand side, with a small adjustment to the housing the new battery + connection can be fitted, the original battery + is fused, i removed this to isolate the small section of lead that use to connect to the battery terminal. The new battery + is fused a the source (battery) if it's good enough for Audi it good enough for me.

Before fitting everything back together a made sure the battery loom was not going to be pinched or rub against anything that could damage it and made sure it had the right amount of slack all the way along, remembering to leave enough and the back to connect to the battery.


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## jutty (Aug 28, 2006)

and the advantage is what :?:


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## charliec (Dec 8, 2005)

I don't want to get into the why's or is this a good idea or not, I want to share my experience so people who are considering this may have another resource to gain information from.

For me the gains are better weight distribution and removal of the large weight inside the rear bumper. This is part of an overall project of making the TT lighter.


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## caney (Feb 5, 2004)

any pics mate?


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## Matt B (Apr 8, 2007)

Would also like to see some pics if you have any.


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## Stub (Mar 17, 2005)

Thanks very much bud, 
What a great How too, 
I have wanted this mod and you just saved me several hundred quid, thanks


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## HighTT (Feb 14, 2004)

charliec said:


> For me the gains are better weight distribution and removal of the large weight inside the rear bumper. This is part of an overall project of making the TT lighter.


I have to agree that the TT is too heavy and every little bit (removed) helps but did you corner-weight the car before you started your lightening process :?: 
It's a good way (weigh :lol: ) of monitoring the effect of what you do.


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## Stub (Mar 17, 2005)

Anyonbe else done this as this is my next mod and any pics would be helpfull??


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## paul kearney (Sep 30, 2009)

I have just changed my battery on my tt and now it wont start ,It turns over but wont start can anybody help


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## lego man (Nov 9, 2008)

paul kearney said:


> I have just changed my battery on my tt and now it wont start ,It turns over but wont start can anybody help


yer is the battery fully charged :lol: :lol: :lol: :lol: :lol: :lol: :lol:

LEGO


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## graeme86 (Jun 3, 2007)

Very insprational thread! [smiley=cheers.gif]

I have been checking out the logistics of doing this in my R32 using all the TT parts - very do-able 

All the metal pieces for the battery box in the back are available separately. 

Just wanted to mention a small correction to one of the part numbers.

According to the latest information I have:

V6/QS wiring harness for battery -ve (earth strap) is part number *1J0 971 243B* (not 1J0 971 234B as noted in first post by *charliec*)

I do have a couple of additional questions however.

Does the new positive loom also replace the harness to the alternator (or part thereof)??

Audi also list an additional ground strap only for 6 cylinder cars - so is that already on the car somewhere anyway?
"Ground strap - longitudinal member: 1J0 971 243 D"
Any idea where that might be?

Thanks for taking the time to do a write up. [smiley=dude.gif]


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## kraftwerkturbo (Dec 26, 2016)

Does ANYONE have ANY photos to complement this DIY?
Please post or link.


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## graeme86 (Jun 3, 2007)

Yes, I have some pics of most of the installation.  
I bought a loom off a guy in the UK and he kindly took some pics of the body shell before he removed the loom. All credit to him for some of these pics.

This is the whole loom:









From the engine bay "fusebox" (where the front mounted battery would be), the loom runs down to a hole on top of the left chassis rail near the firewall:

















The loom then runs _inside_ this chassis rail that curves down under the front floorpan. (The fuel runs run inside the rail on the right side of engine bay in a similar fashion).

It then emerges from the rail in the front footwell floor from this oval shaped hole:









When it comes out of the floor it actually runs _under_ the crossbeam shown in this picture (loom was already partly removed when picture taken):









From there it follows the trench in the rear left footwell and heads over towards the side panel to run up the side of the rear seat:









The loom is then layed out around the rear hatch area and sits under the side trims:









Finally it leads into the battery box coming in from the rear panel area:









Hope that helps!

Graeme


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## kraftwerkturbo (Dec 26, 2016)

Thank you much. Darn, that will be a lot of (removal) work to install in my Mk1 TT225. 
Is the spare tire well different from the V6 to the TT225? I don't think the shown battery will fit into my well. And don't want to cut/weld at this time.


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## David C (Apr 15, 2013)

kraftwerkturbo said:


> Thank you much. Darn, that will be a lot of (removal) work to install in my Mk1 TT225.
> Is the spare tire well different from the V6 to the TT225? I don't think the shown battery will fit into my well. And don't want to cut/weld at this time.


Yes the V6 & QS have a battery box section to the side of the spare wheel well, as shown in that pic.
It is because of that that QS & V6 rear silencer are different to "normal" 1.8T


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## kraftwerkturbo (Dec 26, 2016)

David C said:


> Yes the V6 & QS have a battery box section to the side of the spare wheel well, as shown in that pic.


What is QS?
Need to find a battery that fits into the 'normal' TT225. 
Stock battery is too tall (and would prefer place in front not rear of well).

Anybody put a Li-Ion there?

https://drive.google.com/open?id=1KSsow ... V6p8kC_WIM
https://drive.google.com/open?id=15jJze ... vKkPkuBMiD


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## David C (Apr 15, 2013)

kraftwerkturbo said:


> David C said:
> 
> 
> > Yes the V6 & QS have a battery box section to the side of the spare wheel well, as shown in that pic.
> ...


qS is the quattro Sport.
(Called Club Sport in some markets.)
It was a 240hp 1.8T engine in a V6 body, so had the battery in the boot like the V6.


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## Andre-77 (Jan 27, 2018)

@DAVID C well done! great job! seems easy but very usefull to do :lol: , only a question witch type of battery have you used?
can you link it to me?

Many thanks!


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## David C (Apr 15, 2013)

Andre-77 said:


> @DAVID C well done! great job! seems easy but very usefull to do :lol: , only a question witch type of battery have you used?
> can you link it to me?
> 
> Many thanks!


The V6 & QS use an 096 AGM battery.
I have a Varta E39


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## Andre-77 (Jan 27, 2018)

thank you David!
so you think that this one: https://www.amazon.it/VARTA-START-STOP- ... 173&sr=1-1 will be right?


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## Blacklab! (Feb 24, 2020)

Nice work I just dont understand what the real benefit is? The battery moving to the rear is not going to make any difference, or am I missing something?


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## Andre-77 (Jan 27, 2018)

There's two big benefit doing this work, first you can save a lot of space in your engine bay...better air flow ricirculation,or you can add an air/water IC easy, for example, or simply you can modify your air blowing for the air filter, taking air from the front bumper. (now placed on the right trought the wheel arch); and second but not least you can re-equilibrate the car weights taking 20 kg from the top to the back (doing it you can remove the 15 kg ballast placed in the bottom right side for improving cornering :lol: ).


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## David C (Apr 15, 2013)

Andre-77 said:


> thank you David!
> so you think that this one: https://www.amazon.it/VARTA-START-STOP- ... 173&sr=1-1 will be right?


The battery you use in a normal 1.8T will depend on where you are going to put it.
When located in the engine bay, the normal 1.8T use an 027 size battery.
If you put an 027 inside the car, use an 027AGM.

Unless you've welded the extra section into the boot floor, you won't have the space at the side for the 096AGM.


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## Andre-77 (Jan 27, 2018)

Now i'm using a 60 Ah battery, i think 027 size...so easly i put back a 027 AGM :wink: clear! thanks!


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## silkman (Jul 29, 2004)

First, this is a great thread for anyone wanting to relocate the battery. Apart from weight redistribution, its very useful if you want to put lets say a water methanol tank where the battery used to be in the engine bay.

But I too I thought the trunk floor was different in the V6/QS, so unless welding a different floor or putting a small li-ion battery I don't see how a standard battery will fit.


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## Spliffy (May 3, 2013)

silkman said:


> But I too I thought the trunk floor was different in the V6/QS, so unless welding a different floor or putting a small li-ion battery I don't see how a standard battery will fit.


I imagine you lose the ability to fit a spare wheel in the well, which when you think about it is just more weight saving 

Nick


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## David C (Apr 15, 2013)

silkman said:


> But I too I thought the trunk floor was different in the V6/QS, so unless welding a different floor or putting a small li-ion battery I don't see how a standard battery will fit.


The V6 & QS have the battery box at the side of the spare wheel well. It is literally an extra section welded in and would be quite easy to replicate.
That and the mounting points for the rear subframe braces is essentially the difference between a 1.8 and a V6 shell.


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## StuartDB (Feb 10, 2018)

So some advice please - this is my 225 passenger footwell are you supposed to add your own holes in the cross member to bring the v6 leads into the groove... but I don't think there's the channel in the chassis?

Is there another way to get the battery leads through the left footwell?

Inside the engine bay I also cannot see the hole, which I assume is behind / underneath the ABS pump?





































I realise the are not very clear.. I just don't want to weaken the car, drilling in things...

It's supposed to be where the leaf is in the footwell, I know you can tap a hole through these sheets..


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## StuartDB (Feb 10, 2018)

Hmm okay, I re-read the initial post, and essentially the passenger carpet will be like every carpet I fitted in my house


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## StuartDB (Feb 10, 2018)

So where do it get from the passenger footwell to the engine bay?


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## StuartDB (Feb 10, 2018)

Can anyone show me their v6 / QS fuse holder? I'm wondering whether I can modify the 225 version or change the spare one for the battery connection and use an inline fuse for the Water Meth Injection pump?


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## David C (Apr 15, 2013)

StuartDB said:


> Can anyone show me their v6 / QS fuse holder? I'm wondering whether I can modify the 225 version or change the spare one for the battery connection and use an inline fuse for the Water Meth Injection pump?


Have you got the full set of V6 battery cables?
The one in you pic connects in place of the normal 1.8T alternator cable & fuse.
The V6/QS fusebox doesn't have a cable coming out the side.

The V6 has a fuse on the 2nd cable on the battery connector at the rear. I suspect that takes the place of the 1.8T's alternator fuse.


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## StuartDB (Feb 10, 2018)

The cable from the side is the power to the fuse box, it was connected to the battery + and the starter motor. That's going to be removed.. I have the V6 battery cable so in the engine bay have that power connector and the starter connector. And the v6 cable goes through the passenger footwell to be routed to the boot, there's a fuse in the cable at the rear 

So where does the alternator wire go to in the engine bay / fusebox if the power lead replaces it?


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## David C (Apr 15, 2013)

Looking at the parts list, there is a big cable from the alternator to the starter motor.

1J0971349LH is the V6 version, which is a loom that includes other small wiring too.







So it looks like you'll need to get a big chunky wire made up to link the alternator output to the starter input.

1J0971349LK is the QS version, but I can't find a pic of that one.


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## StuartDB (Feb 10, 2018)

Thanks, that sounds reasonable... 

so the alternator charge travels straight back to the battery and is fused on top of the battery in the boot. 

I hate little auto-electrics, I set fire to my VW T25 earth crown under the glove box whilst testing a sensor in the engine bay at the other end.... if this goes wrong I'll get fired into space


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## StuartDB (Feb 10, 2018)

So connected up the v6 starter cable, moved the alternator cable to the starter motor too (this is mind boggling to me - electricity both in and out?) Like a prossie  
And the rear battery loom connector replacing the alternator connector and chopped off the side connector (Not in that photo - might try and take it properly out but you need to prise off the back of the fuse box)




















I think I should test it before I fully lay all the carpets etc back on... I should have enough bits down to start and run the car, even though no charge circuit.. I just need to make sure the battery starts it and the alternator charges it and hope bit doesn't suck in a screw driver


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