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Battery Relocation to Trunk + Big 3 Upgrade - build thread

39K views 64 replies 21 participants last post by  WhiteBlurrST  
#1 ·
It's time to start the relocation project of my battery from the stock location to the trunk. Weight savings + freeing up some real estate in the front end are some key factors. I am also aiming to keep my spare tire.

I'm going to try to keep this thread updated with, materials chosen, pictures of materials and install photos. This build will be focused on ease of maintenance and future proofing for upgrades in the months to come.

I will also be upgrading, well adding on to the "Big 3"
●Power to Alternator - via aux charging post - w/ inline fuse
●Ground to Battery - via aux charging post
●Engine Ground / Alternator

All wire will be upgraded to 0 awg oxygen free copper (ofc)

Here are some pictures of what we are working with so far.


Main battery ground point






And here is one of my MFT Sony Amp (don't know if I'll have the issues)?


Feel free to drop comments- suggest products etc. I have nothing set in stone right now as far as end game. I know I want it to be nice, clean and be able to power a decent sq system in the future.

Thanks for reading and stay tune for updates in the near future. I am going to be ordering some parts shortly.
 
#5 ·
The -AF series amp will require a load network on it to keep from overheating, as I am guessing you may have suspected by your comment about 'issues'.


Drive it like you stole it!
 
#8 ·
It's time to start the relocation project of my battery from the stock location to the trunk. Weight savings + freeing up some real estate in the front end are some key factors. I am also aiming to keep my spare tire.

I'm going to try to keep this thread updated with, materials chosen, pictures of materials and install photos. This build will be focused on ease of maintenance and future proofing for upgrades in the months to come.

I will also be upgrading, well adding on to the "Big 3"
●Power to Alternator - via aux charging post - w/ inline fuse
●Ground to Battery - via aux charging post
●Engine Ground / Alternator

All wire will be upgraded to 0 awg oxygen free copper (ofc)

Here are some pictures of what we are working with so far.

Feel free to drop comments- suggest products etc. I have nothing set in stone right now as far as end game. I know I want it to be nice, clean and be able to power a decent sq system in the future.

Thanks for reading and stay tune for updates in the near future. I am going to be ordering some parts shortly.
Looking forward to this. I'm interested in something similar, except for the spare. That was replaced by a lightweight 12V compressor and a plug kit on day one. Sub'ed. JP
 
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#9 ·
Subbing as well. Good luck! Don't forget the fuse 12" or less from battery positive. Have you planned where to route the main positive lead from the engine bay back to the battery?

Big fan of the KnuKonceptz wire/fuses/holders I'm running with my Braille and relocate in the Merkur. 4AWG main power, 0AWG ground.

Image
 
#10 ·
Sub'd - love this concept. Don't the lithium/agm/braile batteries need a special charging cycle?
 
#11 ·
If you look at that massive, 4 gauge copper ground that ford includes on the battery, you will see that a big 3 is not necessary. there is plenty of current transfer up in the engine bay. the ST3 comes with a 160a alternator...
 
#12 ·
Big 3 could improve the ground, if you pull the ground post you will notice it is painted under the post AND inside the threads. Chassis ground should be unpainted to provide best conductivity, in my opinion.


Drive it like you stole it!
 
#13 ·
Could improve the BAT- terminal to Ground, maybe. Ground is really the case of the alternator. I've actually seen ground loops from these kits improperly implemented.
 
#18 ·
SUB'D Eager to see the engine bay less cluttered
 
#19 ·
Do mine once your done to :)
 
#22 ·
If you guys need wire I know a gentleman who sells quality wire at 20% or more cheaper than knu. I believe the 4 gauge may be even more oversized than the knu product. All I know is the 8 gauge I bought hardly fits into 4 gauge terminals, and the 4 gauge stuff hardly fits into 2 gauge terminals. And it was cheaper for me to buy two runs of 4 gauge versus 1 1/0 OFC kit from knu by a lot.
 
#23 ·
4 words... Sky High Car Audio

amazing pricing on oversized wire
 
#28 ·
To get from the stock location back to the hatch is about 20 feet per cable.
 
#30 ·
I am planning on grounding all of the factory locations together, the chassis grounds all have paint on them.
 
#31 ·
Understood, but if you clean the factory engine to chassis ground locations (sand clean, electronics clear coat) and then do the same for the battery ground in the hatch, you shouldn't have to run a 20' wire up from the hatch to the engine bay. Grounded to chassis is good to go.

With my setup above, my engine hoist to battery negative reads 0.2 ohms.
 
#32 ·
Update?

I want to do this so I can put my WMI tank up front where the battery goes...
 
#35 ·
Nothing major yet unfortunately. Had to register and plate my ST and Escape in TX as I relocated from California, black Friday spending and now Xmas spending. Plans are still to move forward, just not as quickly as anticipated. I've got most of the smaller parts but haven't went forth for the battery or power/ground wire purchase yet.

Battery I am looking at the Braille B2317. It's not the lightest..but still 16-17lbs (if I recall) lighter than the stock 33lb battery.

I want a balance between light weight that can still power a decent audio system.

Wire will most likely be 0awg KnuKonceptz.
 
#34 · (Edited)
I did this on an old VW GTI. Used #2 welding cable and ran to the starter. Grounded the battery to the chassis in the rear. I left the original wiring in place and would drive up to folks and say that I thought someone had stolen my battery. They would pop the hood and sure 'nough, no battery. When I started the car to drive off their eyes would get big.

You can gain (a little) hp by cutting the alternator field voltage during wide open throttle operation. There is probably already in place a circuit that cuts the AC during WOT.
 
#38 ·
(copy post from the other battery relocation thread)

I've put this on hold temporally until I devise a way to clean up all the wires that will need to be wired into the "new distribution" block in the engine bay.





The last picture is Fords makeshift power distribution block. Most of the wires look like 10-12 gauge, with 2-3 of them being 8 gauge, and possibly 2 4 gauges.
After seeing the clusterfkuc, I'm not sure if I am going to use 2 (4) outlet mini ANL fuse blocks or just keep the factory panel, and mount it to the fuse panel to the right somehow. I'm still planning this part. I'm just not sure if I want to go through and rewire all of those fused powers. Would only be a few hours of work, doing it properly. to be continued...
 
#39 ·
So here is the first major update.




The plans are to move forward full steam ahead.
Battery will be mocked up and mounted by the end of the weekend if I can get the rest of my parts here on time.

Relocation of the fuse panel that attaches to the OEM battery tray parts have been ordered. That should all arrive by this coming Monday and should have the project wrapped up by the end of that week.