The Big 3 & Battery Relocation

[mcanderson0]

Background:
My daily commute needs bass (full audio install & Big Three) and I want to relocate my battery to the back seat area. Seats & belts are permanently removed, giving me a lot more room for my mountain bike to slip through the trunk. Better weight distribution is a plus, and i have the room to link another battery for future audio power expansion. I temporarily removed all interior panels for ease in sound deadening.

The battery is a 75Ah Optima Yellowtop (largest Deep Cycle) weighing about 60 lbs. I believe I could get the hood to shut with this battery mounted in the stock location, but relocating makes sense and is very little extra work versus only doing the Big 3 & audio.

The battery is housed in a marine-style battery-enclosure and will be vented to the exterior.

Ground:
In the engine bay, removed the small wire that was connected to the stock battery terminal and chassis-ground it. Then, removed the stock negative battery wire from the engine bay completely.

Detached the ground cable mounted from the driver side chassis on one end and to the engine block on the other end. Also detached the power cable thats bolted to the alternator, starter, and battery. I used those two old cables like a 'harness template' to cut the new 1/0 cables to length and so i could properly clock the new eyelets to the correct angle prior to crimping. Used some heat shrink tubing to cover any exposed parts, then bolted the ground cable at the chassis point and the engine point.

Power:
I temporarily have my stock battery in so the power cable connects from alternator, to starter, to battery positive.

To be continued:
Battery relocation. Once I remove the battery from under the hood, I can mount an insulated power terminal to the old battery tray. This is where the power cable from the starter and alternator attach, and also where the ECU power harness attaches. The stock battery tray still serves as a splashguard for the ECU. Soon to install some new 1/0 cable from the insulated terminal, thru the large firewall grommet, and to the battery location. Battery current sensor will be relocated to the battery by splicing in 12' of wire for 3 wires. One wire is 5V, another is ground, and the third is a 4-20mA data signal. If I cut out a few inches of the stock 22a wire and splice in 12' of 16a wire to extend it to the back, the resistance change is negligible. Update & pics to follow.

 

[troy_audi0]

If you are doing a big system why not swap the front battery to a Deep cycle and toss in a 200a relay add the second battery in the back??
The more voltage you have on tap the better.. Right?

I think it would just make it better.
Any alternator info?
Going bigger adding one to the system?

What are your Audio plans?
Going to compete?
MECA/IASCA?

 

[mcanderson0]

It really seems like no one is doing battery relocation and I want to do it to balance the car. I'm hoping to get some feedback on this battery current sensor.

I thought about a second battery, but the real star of the sound system is the 10farad hybrid capacitor, which will most likely cover my voltage needs on the system. The new hybrid caps bridge the gap between caps and fast charge/discharge batteries. Plus 10farad is oversized a bit. So I think a second battery seems like a lot of weight to add for little advantage.

Stock alternator, until it can't keep up anymore. Is there a common swap for the sonics?

I've never competed before, I just love music. I've run Pioneer subs for the better part of a decade and I can't wait to hear these twin Pioneer TS-W3003-D4's.

 

[mcanderson0]

Bending the battery hold-down bar. Also, connecting the wire run for the battery current sensor

 

[mcanderson0]

Pic

 

[troy_audi0]

keep it up

 

[mcanderson0]

Live Updates

New 13'-long 16ga 3-wire run for the battery current sensor (the 3 wires are: 5V+, neg/ground, and a 4-20mA signal). I grabbed a new AC Delco battery current sensor connector (comes with heavier gauge wire than stock).

 

[mcanderson0]

Live Updates

Getting this dirty lil girl stripped down

 

[mcanderson0]

Live updates

Current sensor mounted on the battery box

 

[mcanderson0]

All the 1/0 is in wire loom and ran on the drivers side. I ran RCA's and remote wire down the passenger side. Here the battery in the back

 

[mcanderson0]

Under the hood, i bent a piece of aluminum to form a bracket. On top of the bracket i mounted an insulated terminal post. The copper bus bar just allowed me to get rigged up and running. I plan to tidy it up under the hood.

 

[mcanderson0]

Car is running great. No problems. Voltage seems steady, so the battery current sensor seems to be working appropriately.

Future plans include simplifying the underhood mounting bracket for the terminal post and also securing the battery with something more permanent. The hold down bar is great, so I need to continue the idea for the front of the battery.

I will also install a full sound system and a new 'floor' that extends continuously from the trunk area and into back seat area. The new floor will be raised about 2-3" from the current floor so I can secure my amps, capacitor, and extra fuse panel.

 

[mcanderson0]

I didnt like the 2 leg bracket so i hacked a leg off.

 

[mcanderson0]

Some detail on the ECU/starter fuse/bus bar connection point. Dremel-tooled some copper bus for fitment.

Just got around to fog light install so figured i'd add some picture detail from the battery-relocation project while i was under the hood. I'll be updating this thread soon with pics of the new battery location and an extra battery.

 

[mcanderson0]

More batteries installed. Voltage is so solid.

Im doing some research on the battery current sensor to determine the effects without one connected. I think the alternator will work at full duty cycle all the time, hurting MPG and perhaps alternator life.

Im upgrading the alternator soon, so im not concerned with life. If MPG is the only downside, then I will be a happy camper.

Since i've already ran the battery current sensor to the back, i could simply add a switch to the line to turn it on or off, depending on if i want max alternator charge (for high current draw for the daily-drive sound system) or MPG (for a long road trip).

Will report back findings.

 

[RMinNJ]

What my friend wanted was a battery in the trunk that could be charged by the car but then switched off from the car and used to power portable devices..inverter to laptop etc. He wants to power a bunch of devices but not drain the cat battery. This setup looks like a good starting point.

 

[2014 Blue RS]

I so want to relocate the battery to the trunk. More room to work and less weight on the wheels.

This is next level! Can you break down some steps to do the basics? I didn't enemy know we had a battery current sensor. Makes sense but never occurred to me.

 

[mcanderson0]

RminNJ, have your friend look into a 'battery isolator'. They are commonly used in the car audio world, but have other applications just like what your friend wants to do.

 

[mcanderson0]

2014 Blue RS, if you are comfortable doing the Big 3 Upgrade, then adding cable to move the battery to the back is easy. Remove panels, route the wire, use wire loom to protect the wire, etc. I removed the back seat entirely, so running the cable was easy. Then I spliced longer wires to the battery current sensor so it would also reach. The bulk of the work is in the start of this thread. I didn't show how to crimp wire, use heat shrink tubing, etc since those skills are easily found elsewhere. If you have any questions pertaining to a specific step of the project, please ask.

 

[2014 Blue RS]

Back seat is out so running some 10 gauge to the bank not an issued. What's the current sensor? Is it that bracket bolted the battery tray?