Battery relocation/trunk refurbish project

Document your Sixer project here.

Moderators: GRNSHRK, ron, bfons

User avatar
tschultz
Posts: 2515
Joined: Wed Jul 07, 2010 10:54 pm
Location: Colorado
Contact:

Re: Battery relocation/trunk refurbish project

Post by tschultz »

Thanks for the detail Bobbo, somehow I missed the .pdf attachement.

I couldn't tell where you penetrated the firewall-- and you mentioned that you didn't need to drill a hole up there. Any photos would be awesome as I was considering something like this for my turbo car if I can obtain a battery box strut bar. It seems like there isn't enough room under the rear seats unfortunately.
http://www.Drive4Corners.com
Image
'79 635CSi Revival
'80 635CSi
'83 633CSi Callaway Turbo continued as 1988 535is Turbo
SOLD: '81 635CSi/A
GRNSHRK
Platinum Member
Platinum Member
Posts: 3710
Joined: Thu Apr 08, 2004 3:24 pm
Location: Gilroy (SF Bay Area) CA

Re: Battery relocation/trunk refurbish project

Post by GRNSHRK »

Tom, there are a couple of plugged holes behind the pedals, at least there is in the series I cars, not sure about your '83 turbo, however :-?

True, can't see where I snaked the cable through, frankly I would have to get in there and get a better look myself [-o<

Under the rear seats, nice idea but not even close to having enough room for the battery :-({|=

Anyhoo, here's a shot of where I brought the cable through from the trunk, from what I recall there was a plug there that I removed, but after 7 years, really not sure #-o

I did put a grommet in this hole, however, the last thing you need is the sheetmetal cutting through the insulation [-X

I'll see if I can get some better shots tonight after worky [-o<

:mrgreen:
Attachments
IMG_1918-sm.jpg
IMG_1918-sm.jpg (62.06 KiB) Viewed 10338 times
:mrgreen:
Bobbo
1980 633 CSi Cypress Green/Pearl Beige
2017 X5 M Sport Xdrive 35i Carbon Black/Ivory White
2005 330 Ci ZHP Cabrio Imola Red/Bone/Black
Image
GRNSHRK
Platinum Member
Platinum Member
Posts: 3710
Joined: Thu Apr 08, 2004 3:24 pm
Location: Gilroy (SF Bay Area) CA

Re: Battery relocation/trunk refurbish project

Post by GRNSHRK »

Tom, it's virtually impossible to get decent shots of where I fed the cable through the firewall :-?

Basically, once you feed the cable up the left hand side footwell behind the carpet, it will be barely visible unless you've got your head down there poking around anyway :-#

Anyhoo, here's a few of shots, one from underneath and 2 showing the cable coming up and wrapping around the top side of the brake vacuum booster and on down to the top of the starter solenoid :roll:

From the inside, it was to the left of that big ass grommet with the harness going through it, passed through the same hole =D>

If you do this process, one other item you will need to add is a separate ground from the engine to the chassis :-k

When I did this, went to hit the starter and of course, nothing [-o<

So I went back and looked at the original negative cable, which of course has this grounding point, a real "doh" moment for me #-o

:mrgreen:
Attachments
IMG_3394-sm.jpg
IMG_3394-sm.jpg (68.32 KiB) Viewed 10284 times
IMG_3393-sm.jpg
IMG_3393-sm.jpg (78.44 KiB) Viewed 10284 times
IMG_3392-sm.jpg
IMG_3392-sm.jpg (84.14 KiB) Viewed 10284 times
:mrgreen:
Bobbo
1980 633 CSi Cypress Green/Pearl Beige
2017 X5 M Sport Xdrive 35i Carbon Black/Ivory White
2005 330 Ci ZHP Cabrio Imola Red/Bone/Black
Image
Kurtamine_
Posts: 66
Joined: Sun Nov 18, 2018 8:55 pm
Location: FL

Re: Battery relocation/trunk refurbish project

Post by Kurtamine_ »

GRNSHRK wrote: Tue Apr 13, 2010 8:15 pm Fellas, attached is the result of the fruits my labor, a project that wound up taking well over a month to complete :roll:

But with the battery tray rotting away up front, I had no desire to reinstall the battery back in that location, which provided me the opportunity to move it to the trunk :wink:

I had also been wanting to refinish the trunk, and this was the time to take care of that as well :-?

Along with a couple of quick shots, before and after (hopefully in the right order...), here's my story 8)

Please feel free to comment, suggestions, other thoughts, all are welcome :-k
Bobbo,

Did you fabricate this yourself? I am interested in purchasing one for my basket case of an E12 :D
'81 E24
'99 miata
'84 E30
'99 eclipse
GRNSHRK
Platinum Member
Platinum Member
Posts: 3710
Joined: Thu Apr 08, 2004 3:24 pm
Location: Gilroy (SF Bay Area) CA

Re: Battery relocation/trunk refurbish project

Post by GRNSHRK »

Fabricate it myself :-k

I wish I had that capability :-?

Trying to recall the name of the fella that was making these, think it was Brent Kemi, might try and do a search on the board [-o<

BTW, shortly after doing this, the Interstate did crap out, so I went with an Optima red top =D>

Which, of course, also just crapped out, the day before I was leaving for Pacific Sharkfest :shock:

Managed to find a replacement in stock at O'Reilly's, to my surprise \:D/

So, wallet is a little lighter, but it was 9 years old, so I think I did OK :-"

I'll see if I can find this guy on the board, although I surmise that he's moved on :-({|=
:mrgreen:
Bobbo
1980 633 CSi Cypress Green/Pearl Beige
2017 X5 M Sport Xdrive 35i Carbon Black/Ivory White
2005 330 Ci ZHP Cabrio Imola Red/Bone/Black
Image
Kurtamine_
Posts: 66
Joined: Sun Nov 18, 2018 8:55 pm
Location: FL

Re: Battery relocation/trunk refurbish project

Post by Kurtamine_ »

+1 on the red top info too. My battery is on its way out so im glad I found this 4 yo post :lol:

I guess I will be fabricating my own. I figured I would ask the thread first before I dive into the project

Thanks!
'81 E24
'99 miata
'84 E30
'99 eclipse
wattsmonkey
Platinum Member
Platinum Member
Posts: 1649
Joined: Mon Jul 16, 2007 2:58 pm
Location: Cheltenham, U.K.

Re: Battery relocation/trunk refurbish project

Post by wattsmonkey »

That brace/battery combo is awesome! I can't believe I missed the pdf too - excellent work and thank you very much.

I'm doing the same thing on my project car, but bought the positive cable from an E36 with the pretty terminal to put in the engine bay.

You've inspired me to be a bit more creative: why am I installing a steel strut brace and fabricating a battery box when I can combine the two!

I'll put mine on the left-hand side though, being a rhd car.

Thanks again. This site is amazing for turning up brilliant stuff,

Rob
"Most of it necessary; all of it enjoyable." LJKS
'84 635CSi, dogleg...itbs and supercharger????? Eaton Mess
Austintatious
Posts: 47
Joined: Tue Jan 18, 2022 5:14 pm
Location: Fort Worth

Re: Battery relocation/trunk refurbish project

Post by Austintatious »

Nice work... But I have a situation and question I would like your input on.

I am about to start work on my 83 euro 635csi and make it the beast I have always wanted it to be. Part of that will be making the car as light as possible and getting weight off the front. I have considered relocating the battery to the trunk, however that will only move weight, not reduce it (in fact it may slightly increase it)

So, what I have found is a Lithium IRON battery that can replace the lead acid battery and weighs only 40% of the LA battery. This will shave about 25 lbs off the nose and the car as a whole. The battery cost about 500.00 dollars and would be a very easy change.

So my question is...

Is the amount of work and dollars spent to relocate the battery worth just spending 500.00 for a lighter battery that is not relocated?
GRNSHRK
Platinum Member
Platinum Member
Posts: 3710
Joined: Thu Apr 08, 2004 3:24 pm
Location: Gilroy (SF Bay Area) CA

Re: Battery relocation/trunk refurbish project

Post by GRNSHRK »

Is the amount of work and dollars spent to relocate the battery worth just spending 500.00 for a lighter battery that is not relocated?
Well, interesting question, for sure :-k

Regardless where you mount the new lighter battery, you will lose that weight, so that's a given :-"

But by relocating the battery, you shift the weight, which is like putting a 75 pound bag of sand in the trunk :roll:

Besides weight distribution, my goal was NOT to put the battery back under the hood, for obvious reasons previously stated [-(

The trunk is really a much better place for the battery to live, you really don't see batteries under the hood of modern cars anymore [-X

You'll have to tell us more about this new type battery [-o<
:mrgreen:
Bobbo
1980 633 CSi Cypress Green/Pearl Beige
2017 X5 M Sport Xdrive 35i Carbon Black/Ivory White
2005 330 Ci ZHP Cabrio Imola Red/Bone/Black
Image
Jlc
Posts: 287
Joined: Sun Sep 27, 2020 5:27 pm
Location: Atl

Re: Battery relocation/trunk refurbish project

Post by Jlc »

I believe he meant Lithium Ion, much like what is in a laptop. Here’s an article:

https://arstechnica.com/cars/2021/02/a- ... expecting/
85 635CSi Bronzit
Austintatious
Posts: 47
Joined: Tue Jan 18, 2022 5:14 pm
Location: Fort Worth

Re: Battery relocation/trunk refurbish project

Post by Austintatious »

Jlc wrote: Mon Feb 07, 2022 1:37 am I believe he meant Lithium Ion, much like what is in a laptop. Here’s an article:

https://arstechnica.com/cars/2021/02/a- ... expecting/
No, I did NOT mean lithium ION.

I meant what I said.. .Lithium IRON or LiFe

To be fair, the article you linked is actually about LiFe batteries, but the person who wrote the article was clueless
And the type of lithium chemistry we're using is iron phosphate, or LiFePO4
here is an example, 1000 CCA , weight 16.5 lbs Built in over/under charge/discharge protection.

https://dakotalithium.com/product/dakot ... y-1000cca/
Jlc
Posts: 287
Joined: Sun Sep 27, 2020 5:27 pm
Location: Atl

Re: Battery relocation/trunk refurbish project

Post by Jlc »

Correct, LithiumIronPhosphate is one that can be used as a cathode in a Lithium Ion battery. I was wrong to say you meant Lithium Ion, since they both mean the same thing. Maybe they used marketing speak to differentiate themselves from other batteries that also used LiFePO4 but called theirs LiIon?Thanks...

At any rate, sounds like a cool way to lose some weight...
85 635CSi Bronzit
Austintatious
Posts: 47
Joined: Tue Jan 18, 2022 5:14 pm
Location: Fort Worth

Re: Battery relocation/trunk refurbish project

Post by Austintatious »

I jsut know that the two batterie types ( Lithium ion v Lithium iron) are different chemistries. The LiFe batteries are much more stable and much lighter despite the Iron,

https://goenergylink.com/blog/key-diffe ... batteries/
Jlc
Posts: 287
Joined: Sun Sep 27, 2020 5:27 pm
Location: Atl

Re: Battery relocation/trunk refurbish project

Post by Jlc »

Austintatious wrote: Wed Feb 09, 2022 10:04 pm I jsut know that the two batterie types ( Lithium ion v Lithium iron) are different chemistries.


They all are Lithium Ion, which is a catch all phrase for a battery that has a lithium ion traveling from anode to cathode and back, just the cathode and anodes may have different compositions depending on the application. The basic concept is the same, whether they are in a car, phone or computer.

Lithium Ion can use LiFePo4 (Iron Phosphate) or LiMn2O4 (Lithium Manganese Oxide) for example, as the cathode.
The LiFe batteries are much more stable and much lighter despite the Iron,
Certainly, although they aren't iron in the sense one may think; unlike a lead acid battery you normally see that uses lead which is ~50-60% of the weight. LithiumIron doesn't have iron plates or grids.
85 635CSi Bronzit
Austintatious
Posts: 47
Joined: Tue Jan 18, 2022 5:14 pm
Location: Fort Worth

Re: Battery relocation/trunk refurbish project

Post by Austintatious »

yes, I should have said "iron" (in quotes)
Jlc
Posts: 287
Joined: Sun Sep 27, 2020 5:27 pm
Location: Atl

Re: Battery relocation/trunk refurbish project

Post by Jlc »

No worries. Sounds like you've found a neat way to lower the weight. Should last a lot longer than a traditional battery so the total costs should be the same or less.

The battery technology is pretty amazing, I'm surprised it hasn't made it to more cars from the factory.
85 635CSi Bronzit
Post Reply