Battery trunk relocation options

[Healey3000]

2 hours ago, dlacey said:

Wherever you put your battery, you want 'the path of least resistance' between your current source and your largest current sink. That means a single continuous suitable gauge cable from battery + to the Starter Motor....every additional fuse/isolator/junction adds resistance & creates potential points of failure. On an '02 its easy to extend the red cables from loom/alternator so that they all connect to the Starter post - this becomes your junction point - no extra hardware required.

Hi,

 

That is very true, electrically.  One may have to compromise a bit since the engine bounces around and a heavy-gauge wire is more likely to suffer fatigue failure.  I used 00 AWG (70 mm2) cable directly from under the rear seat to an e36 junction box mounted on the brake booster bracket and then a short 2 AWG length of cable looped downwards to provide a service loop before attaching to the starter (basically, mimicking BMW methods).  The nice thing about this junction box is that it has a jump terminal with a nice cap.  I have a detailed post on this from a couple of years ago.

 

 

Edited May 28, 2020 by Healey3000

[xr4tic]

To update this thread, I did the Li-ION battery as @NYNick did

 

My homemade mount weighs more than the battery.

[xr4tic]

For some reason, it won't let me select 2 pictures in a response?

 

This is just angle iron welded up, was able to use 4 gauge wire for the starter/ground, 8 gauge for the alt/main power.

 

If you did a remote mount, you need to double that gauge.

 

[SydneyTii]

11 hours ago, tomphot said:

The PO has moved the battery to the trunk.  It was sitting in the corner, I found this cool mount for the Optima.  It doesn’t take up much room and has a handy cutoff. 

Do you have any clearer pictures of how you mounted the cut off?

TIA

[tomphot]

5 minutes ago, SydneyTii said:

Do you have any clearer pictures of how you mounted the cut off?

TIA

Here you go - the PO did thus as well.

[NYNick]

11 minutes ago, SydneyTii said:

Do you have any clearer pictures of how you mounted the cut off?

TIA

That's the best looking trunk mount I've seen yet. Dumb shock tower brace delete!

[Vicleonardo1]

Like this thread.

I think it has saved me a bit of time, effort and money when I was toying with the idea of doing a battery trunk relocation. I am glad it took me so long to pull the trigger. It just seems a ton easier to just get a lightweight tiny battery.  (I don't have a Tii or sidedrafts etc.) 

Just would like to see what the lifespan of these batteries are going to be. 

 

Cheers! 

[tomphot]

11 hours ago, NYNick said:

That's the best looking trunk mount I've seen yet. Dumb shock tower brace delete!

I really dislike the brace mount!  When I bought the car, the PO had the battery mounted in the corner being held down by bungee cords!  All the other work with the relocation was done well so that was strange.  I did a lot of searching to find a nice clean solution. 

[SydneyTii]

For a trunk mounted solution, especially if you have raised boards to accomodate a larger spare, like the turbos have, A battery box with cut out would be a good solution.

I trial fitted/placed it (the TEP one) yesterday, I didn't think it looked that bad, sure it fills that space up, but I don't use it anyway.

 

Edited May 29, 2020 by SydneyTii

[AustrianVespaGuy]

On 5/27/2020 at 9:21 PM, Healey3000 said:

On an '02 its easy to extend the red cables from loom/alternator so that they all connect to the Starter post

I don't like this as it's hard enough already to protect that starter post from tool-touches.  We all disconnect our batteries for planned work, but hell even I've dropped a screw driver on that dumb thing once while just adjusting a carburetor! Mine's now pretty well insulated, but that was touch and I think it'd be impossible with 3 wires running to that location.

I also don't like the rear braces, as drilling holes in those poor rust-prone strut towers just gives me the willies!

Under the seat or smaller/lighter up in the stock location remain my favorite options.  Though I feel I might have already said that before. . . sorry for repeating myself!  Prices come down on the Antigravities yet?

[Vicleonardo1]

1 hour ago, AustrianVespaGuy said:

I don't like this as it's hard enough already to protect that starter post from tool-touches.  We all disconnect our batteries for planned work, but hell even I've dropped a screw driver on that dumb thing once while just adjusting a carburetor! Mine's now pretty well insulated, but that was touch and I think it'd be impossible with 3 wires running to that location.

I also don't like the rear braces, as drilling holes in those poor rust-prone strut towers just gives me the willies!

Under the seat or smaller/lighter up in the stock location remain my favorite options.  Though I feel I might have already said that before. . . sorry for repeating myself!  Prices come down on the Antigravities yet?

 

You can go smaller and lighter with some Powersport/Motorcycle batteries (i.e. Wicked Start 500 CCA Dimensions: L 6 7/8 x W 3 3/8 x H 6 1/8").....for some space and weight savings (about 10-15 lbs lighter than a 24R lead acid battery) for about 1/2 the price of a Antigravity. It is nothing like an antigravity in size and weight savings, but it does shave a few inches and is about 1/2 the weight of a standard battery. 

[AustrianVespaGuy]

@Vicleonardo1 Thanks, but I actually just made the decision (finally) to just replace my 10-year-old worn out Odyssey PC680s with new PC680s.  I already have them nicely tucked under the back seat with great brackets, kill switch, and all the wiring in place, so I'm lazing out and going for the simple R&R rather than a new wiring project!

[MoBrighta]

On 7/26/2019 at 6:37 AM, NYNick said:

May I ask why you're relocating the battery?

Why did you?

Most folks don't like the stock location for many reasons,  Here are a few.

.

1) All that weight (original batteries) so far from the center of mass;

2) Vulnerability -- in a frontal collision, a punctured battery likely means no driving home.

3) Handling -- nose-heavy on the left side is unbalanced; equal load at each corner is better.

4) Maintenance -- having less stuff under the hood makes almost everything easier.

5) Weather protection -- freeze-bake cycles, wetness, road crap, oil fumes, antifreeze, you name it, it's bad for a battery.

6) Envy -- E24 Sharks, M cars, high-zoot models have their battery in the trunk, must be for a good reason.

7)  How do you make a car faster and more reliable?  "Add Lightness and Simpli-cate." 

 

Hope this helps, but I have probably overlooked about 42 other good reasons.

 

You added lightness with a 3 lb. battery, right?

II moved mine under the back seat, doing the "cutout a flap / welded in box / thick cable to the starter" model.

Similar to the way uai did, I even had a 106 liter fuel tank in the same location he did - not factory, custom.

[SydneyTii]

9 hours ago, AustrianVespaGuy said:

also don't like the rear braces, as drilling holes in those poor rust-prone strut towers just gives me the willies!

I kinda get this concern to some extent, but they are like a tube that passes through the cavity formed by that section, I don’t think drilling holes would generate rust if they are well prepared, which is what I was asking earlier, I think that area should be coated with a good underbody anti rust sealer after the holes are painted. Those mounts already have a big hole in the top that the shock connects to.

you can all say I told you so in 5 years when my shock punches through my trunk lid?

 

I like the battery under the back seat idea but I grew up with minis and I can tell you how many had rotten battery boxes, a bit out of sight out of mind, I wonder if a optima yellow or red top would fit?

Im thinking about a couple of air filter options one that passes through the battery space for my Tii so I just need to work out where’s best for my car... not a bad problem to have!?

[MoBrighta]

4 minutes ago, SydneyTii said:

... I wonder if a optima yellow or red top would fit? ...

Fits fine, I had one under the seat for fourteen years of daily driving in Denver and up the hill in Rocky Mountain winters.  WISH i had a headlights-on warning buzzer, after forgetting the parking lights so many days I can't remember, it finally went south.  I miss that battery!  Amortized cost, about $5 / year.