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Dual Battery Wiring and Electonics Install

posted Dec 25, 2011, 7:31 PM by Chris Agneta
Upon starting the Build I had an Optima Yellow Top battery left over from my blown up Honda. Having always wanted to run dual batteries in a vehicle I spent some time researching dual battery setups, I kept in mind a few important things. First I knew I would need a solid mount for the battery, as vibration is the most common way to destroy a perfectly good battery I wanted something secure to do the holding. Secondly I knew that I had a battery that would be In need of some form of isolation from the primary battery once the truck's alternator was turned off. I did some creative Google searching and found that the diesel trucks came with a second battery tray mounted over the windshield washer reservoir we managed to pick one of these up at a local junkyard while on a hunt for a front fender. To address the problem with the charging systems and isolating the batteries I decided that normal battery isolators, or a more conventional continuous duty solenoid wouldn't be in the future for the truck, I needed something more reliable and more importantly totally submersible. It's no secret that I'm a fan of overbuilt electronics so I immediately turned to a market that would have the second highest quality electronic switches. (second only the the insanely overpriced aviation market) By that, I mean that I went straight to the marine Industry. I looked within the marine industry because their products get exposed to everything that one could call "worst case" for electronics. These electronic components are subjected to high temperatures in the engine compartment of a boat, they are also subjected to chemicals in the air in the engine compartment, and most importantly to me, these components need to be able to function at 100% even when submerged in liquid. Even though I was planning on mounting the solenoid above the fan shroud, I wanted to be able to have it work even if I drive through a water crossing and it goes under. The idea of some day driving into an obstacle, and not having the battery that my winch is connected to charged by the alternator scares me a little. After much research I bought an Automatic Charging Relay from Blue Sea Systems. This unit has Start Isolation feature, and a batteries combined indicator both on the unit and one that gets mounted in the cabin, and my favorite part, this charging relay is totally submersible for up to 30 minutes. This beauty is entirely automatic once it senses a charging current from the alternator for 30 seconds it combines the batteries and allows them to be charged together by the same alternator, then 30 seconds after it senses the charging source removed, the ACR separates the batteries again. The two batteries were then wired in parallel with the ACR between them. The Dual battery setup has been installed for a few months now and it works great both batteries are in very good health and the ACR has performed flawlessly so far!

The ACR installed inline and on the right is a picture of the install of the dual battery setup.

The next part of the power distribution project was to upgrade the ground wires and increase overall charging system performance
This was done by installing a four gauge positive cable from the alternator to the battery, upgrading the frame ground to a two gauge cable, upgrading the engine ground to a two gauge cable, and upgrading the cab ground to a two gauge cable as well.

The picture to the left shows the four gauge cable running from the alternator to the batteries, and the other four gauge cable runs from the primary battery through the ACR and then on to the secondary battery.

The power distribution for the accessories under the hood was now complete, I did also run a four gauge cable into the cabin for the amps and accessories that I would use inside the truck.

The next Wiring feat was to run the 8ga cables from the secondary battery for both power and ground that would be connected to the power distribution center for the four HID ballasts,  the Reverse lights, the rock lights, and the E-locker and all the relays to support these things. The power distribution center is housed within an ammunition box that is mounted next to the radiator on the passenger side. Even though the HID ballasts and the relays I choose for the project are waterproof, I still wanted to use something that would keep my connections watertight and more importantly keep the electrical components clean so when I need to add something to the system all I would have to do would be install a new grommet and run the new wires.

This is the Power Distribution center while it was being wired. The four HID ballasts are on the left side, the Positive and negative distribution blocks are not in the box yet and the relays for the E-Locker, Reverse lights, and

Inside the truck I chose the following components to support my activities and general sanity on long commutes.

-Alpine IDA-X200 Deck
-Parrot KCE-400BT Bluetooth module
-AudioQuest Aux Cable
-Alpine Full Speed iPod cable
-XM Radio Receiver
-Sirius Slim Antenna Upgrade
-Kicker KQ30 Signal Processor
-Alpine MRP-F300 Amplifier
-Kicker KS65 Coaxial Speakers
-Kicker TC10 Subwoofer

-Uniden PRO 520XL
-PA System
-Uniden BCD996XT
-External Speaker for BCD996XT
-Two Motorola MR350 Two-Way radios

-On road Nav is provided by Two TomTom units
-Off Road Nav is provided by a Lowrance Safari Handheld GPS unit

-DEI Door Lock Actuators
-Viper 5301 Two way alarm/Remote start system

The amplifier, scanner, and CB radio are mounted high on the seat back, rather than under the bench or on the back of the cab.  They are mounted as high in the cabin as possible so that if the interior of the truck were to become wet the electronics will have the best chance of surviving.  The power and signal wires are run inside wire-loom from the secondary battery to the back of the bench, to keep the install as clean and safe as possible.

 The Valentine 1 Radar detector mounted above the Rear View mirror.

The amplifier, signal processor, and scanner mounted to the seat back. Before wire-loom and after wire-loom.

Alpine Head Unit installed.

I chose to use a pair of  AudioQuest RCA cables as my aux cable the braided wires and all metal connectors are both cleaner looking and perform better both in durability and sound quality over a standard aux cable. I have the Alpine Full Speed iPod cable run to the glove box that allows me to have an iPod stored in the glove box and to have full control of it from the head unit, this is a nice extra because it keeps the iPod from getting knocked around the cabin when driving off road.  Lastly, the KQ30 Works perfectly to tune the sound from my coax speakers to blend flawlessly with the sub.

That just about sums up the electrical modifications to project K1500 so far.

More to come on the E-Locker install in the next few days!