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Yet Another Dual Battery + Inverter Install (PICS!)

javyy

Full Member
I just completed a dual battery install using and combination of OEM and aftermarket parts.  Also includes a 1/0 AWG cable through the firewall to feed a 2000W inverter installed in the back seat.

Here are the OEM parts used (translated into English from GM Parts Terse):

15246518 -- Battery Tray.  This is necessary!  The stock "lower fender brace" is not the same.
10246636 -- Batt Insulator.  Foam cover that goes around the battery.
14005061 -- Retainer.  This is the rubber block that clamps down on the lip on the lower part of the battery.
11509853 -- Battery holddown block bolt.  This is the bolt that holds the rubber block that holds down the battery to the tray from the bottom.

Other parts from CustomBatteryCables.com:

The negative battery cable is actually a pre-fabbed part.  I got it from CustomBatteryCables.com:
"Negative 28 inch side post 1/0 gauge battery cable w/18 inch lead"
http://custombatterycables.com/application/GM_battery_cables.htm

It actually has two cables coming out of one terminal: a 1/0 AWG that I connected to the engine block and a 4 AWG that I connected to the body via one of the bolts that holds on the battery tray.

2 AWG cable, 8 feet for battery to isolator center terminal and isolator to red battery box (I had a bit extra).
4 AWG cable, 1 foot for fuse to isolator battery inputs
1/0 AWG cable, 20 feet for red connecting battery box through firewall to back seat inverter install
2 Bussman fuse holders with AMG fuses
1/0, 2, and 4 AWG ring terminals for all the connections.

From BuyHeatShrink.com:
3/4" Red 3:1 adhesive lined heat shrink, 4'
1/2" Red TechFlex braided sheilding, 25'
1/4" Green TechFlex braided shielding, 25'
1/8" Black 2:1 heat shrink for small terminals for Hellroaring remote switch/LED.
100 Pack Heat-Stabilized zip ties

Misc.
Red, green, and yellow 20 AWG stranded for remote switch.
NGK locking toggle switch
ATC fuse holder and 3A fuse, to protect the 20 AWG coming off the main battery post on the Hellroaring to the remote switch.
Green LED, 1/4" panel mount.
Resistor 470 ohm for LED hookup.


The battery is an Odyssey PC1500 with both side and top terminals, chosen due to the many thumbs up on here.  I did not use the top terminals, so I 5-minute epoxied the plastic covers on that come with the battery to keep them from falling off.  The stock upper fender brace needs to be removed to fit this battery.

The Hellroaring isolator needs a remote switch to control its operation.  The three small terminals on the bottom of the isolator plus a single 20 AWG (3A fused! -- you can see the holder tucked in above the three red cables by the firewall) coming off the lower battery side go into the green sleeve and head back into the cabin, where I have a remote green LED and locking toggle switch installed.  I have it setup with the "battery backup" configuration which uses the two main battery terminals in parallel.  Normally the isolator connects the batteries together when the voltage sensed from the center terminal (from main battery/alt) climbs past threshold.  This is the automatic mode.  The switch is a manual override -- in the "on" position forces the batteries to be connected.  It is used when you want more power to start the truck, main battery fails, etc.

Now onto the pics!

The 2 AWG from the battery hooks up to the right side of the Bussman AMG 175A fuse, and the left side of the fuse splits into two 4 AWG feeds into the A/C terminals on the BIC-95300B. I chose to do this instead of using the 6 AWG jumper shown in the instructions.  The center B terminal has the 2 AWG going across the firewall to the red battery box (had to grind down the sides a bit to ensure they would not touch, as the terminals are quite close together). 

The ground connection goes through its own 3A fuse, visible on the left.  This one comes with the Hellroaring kit.  I just attached this one to one of the sheet metal screws holding the Hellroaring to the firewall for ground.

Here are the red battery box connections.  I used this as the main hub for all the hi-amp connections:


I had to dremel out some material to make room for the extra cables.  The 2 AWG from the Hellroaring B terminal is going into the top, and the 1/0 AWG to the inverter is going out the bottom.  The stock battery cable is untouched on the left.  When I upgrade the alternator I will have to trim a bit more to clear the larger alt cable, but for now the stock one still fits in nicely.

Here is the ground location for the aux battery:


and more detail:


The M10-1.50 threaded hole was already there in the block, I just cleaned it up with a wire brush, bought a bolt, and used it!

The 4 AWG tail from the ground cable just gets hooked to the body via one of the nuts that hold on the battery tray (not shown).  I wanted this upgraded block-to-body ground since I have the 2000W inverter in the back grounded to the body (one of the seat bolts).  When I install the big alt I will also replace the main battery ground cable with one of the same.

Here is the protrusion through the firewall:


I used a 1/0 AWG firewall grommet.  The location seemed to be destined for this -- there was already a circle cutout of the insulation and there was a detent marking the center that was visible inside and out.  I just went at it with a dremel until the grommet fit in.  It screws in and has a nut that threads on from the inside.  I used some blue RTV silicone to keep it watertight.  You can see the 1/0 AWG for the inverter as well as the 3 20 AWG wires in the green TechFlex that are for the in-cab LED and toggle switch.  There is another Bussman AMG fuse inline on this cable which is visible on the left.

Here is the in-cab install of the switch/LED:


I actually just installed the panel mount LED in the lower hole in the bracket mount for my Prodigy brake controller.  It is a low power, plane-jane LED in a plastic panel mount.  I installed a resistor inline with it.  It is noticable from the driving position without being distracting.  The hole was already there, just ran a 1/4" bit through it to enlarge it a bit.  The toggle on the right is the Hellroaring switch.  It is a locking toggle to prevent accidental tripping -- you have to actually pull the switch lever down to toggle it.


Here is the overall view:


I used the white cable clamps that came with the Hellroaring kit to attach the 2 AWG cable running across the firewall.  The rest is held with heat-stabilized zip ties.



 

newavguy

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Full Member
Nice writeup (y)
 

ddr2467

SM 2010
Full Member
hey javyy it seems that you didnt go with the hellroaring remote module switch... is this correct??? if so why not and furthermore how did you wire the isolator to whatever switches you DID use??? your setup is awesome and i have most of what you used on order as i write this... when i order the rest from hellroaring i just want to know if i NEED to order the remote module or not... id like to NOT have to use this because i plan to have 5 led switches in a row and would love to be able to use one of them to control the battery set up if i can... thanks again!!!  (y)
 

javyy

Full Member
ddr2467 said:
hey javyy it seems that you didnt go with the hellroaring remote module switch... is this correct??? if so why not and furthermore how did you wire the isolator to whatever switches you DID use??? your setup is awesome and i have most of what you used on order as i write this... when i order the rest from hellroaring i just want to know if i NEED to order the remote module or not... id like to NOT have to use this because i plan to have 5 led switches in a row and would love to be able to use one of them to control the battery set up if i can... thanks again!!!  (y)
This is true.  To me is was just cleaner to not have another box to mount.  The metal ledge under the dash provides a secure place to mount the switch(s) accessibly yet out of the way.  The low-brightness panel mount LED is on my brake controller bracket where I can see it while driving but it is not distracting at all.  There are also NGK switches to be found with integrated LED as an option.  As far as wiring it up, the Hellroaring kit comes with an excellent wiring diagram for the switch and remote LED and I just followed that. I choose to use a two-position switch instead of three position and use the "ON" and "Automatic" modes only of the isolator. 

I did have to run my own wiring & make up (crimp/solder/heat-shrink) my own connections from the three small terminals on the Hellroaring isolator to switch and LED inside the cab.  These are via three small 20 AWG wires contained in the green TechFlex shown in the pictures.
 
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