Now that the dual battery mounting tray is installed, the next step is installing the battery's and connecting the wires.
Install the two battery's with the posts facing outward.
Connect the J bracket on both sides and mount the hold down bracket.
Next install the smart isolator. NOTE: The isolator has 3 wires, but the only one used is the black that goes to chassis ground.
Since I have a ton of accessory wires, I installed a power buss-bar. Buss-bars help keep the wires somewhat organized and away form the battery terminals where they can cause corrosion. These are available at various locations. I found mine at a boat supply house.
Reconnect the evap Purge solenoid. Note it should be mounted somewhat upright. I wire tied it to a wire bundle. The OEM bracket was removed with the battery tray.
Do a last check to verify that all connectors are connected and the wires are connected properly.
Here's a final pic of my install.
Conclusion
The dual battery project was a rewarding experience. I highly recommend this for anyone that has added accessories that require direct battery connectivity.
The step of the dual battery project is reassembly. The Benchmark design guys have this project nailed. The fit and finish of their parts is outstanding. Everything fits perfectly with no modifications whatsoever.
Reassembly
The first step is cutting the T piece of the firewall insulation. This step needs to be completed so the new battery box fits securely to the firewall.
Next, mount the battery tray with the three washer nuts. Do not fully tighten them yet. The tray is perfectly sized and slides right in with minimal effort.
Then connect the fender well screw
TIPM bracket install
Benchmark Designs engineered the TIPM module mount well. It is a separate part that bolts onto the main tray with two screws. This is a nice design because it keeps the try small and easy to manage when installing and it keeps the top of the shock absorber exposed (more on why that is important in a minute).
To start, mount the original TIPM bracket to the mount. This is keyed so the bolt holes only line up in the right direction.
Next is a bit of an unusual step, but required. The Benchmark tray is supporting two very heavy battery's. The forward driver side corner is a weak point. Benchmark cleverly took this into account by creating a straight bracket that is bolted through an existing hole in the passenger shock tower. The other end connects to the tray making a very strong structure.
Getting to the hole in the shock tower to mount the bolt, however, is not easy. It is behind the shock. I have large OME shocks and there is no way to get behind them. This actually became an easier task than I expected. I found it was easier to install the bottom bracket by removing the top bolt of the shock before installing the TIPM mount. Thanks to Benchmark's separate TIPM tray, this keeps the area clear with easy access.
Shock with top bolt removed.
With the shock lose at the top, there's just enough room to bolt on the bracket. .
Next, you reinstall the shock, mount the TIPM tray and connect the top of the straight bracket to the tray.
At this point the battery box is installed. However, we still have to deal with the factory air filter mount that we removed. The way Benchmark Designs handles this is by cutting the air filter mounting bracket from the large battery box assembly. I was a bit skeptical of this, but it worked perfectly. After cutting, just mount it back in the same location.
Next reinstall the power steering fluid holder and install the factory air filter enclosure.
The final step is to make sure all nuts and bolts are tightened. At this point, the battery box is mounted! Next up is connecting the wires and installing the battery's.
Most modified Jeeps can quickly overtax a stock electrical system. Winches, lights, audio systems, etc. put a bigger load on the system than what it was designed for. A power spike from a winch or turning on powerful lights can easily damage the sensitive electronics. Notwithstanding the fact that everything has to be connected to the battery, which makes it a rats nest of wires. I've added quite a bit to my Jeep at this point. A clean up in the battery compartment was in order. A dual battery system will take care of the power surges and clean up wiring, so I decided now is the time to tackle this project.
Unfortunately, Chrysler doesn't offer a dual battery option for Jeep. It's up to the owners to figure out how to do it. There are a few after market vendors that sell dual battery kits for the Wranglers. I did a ton of research on which one to buy. My research always pointed back to Benchmark Designs. They are a small mod company in Seattle, Washington that doesn't make a lot, but what they do make is excellent. I decided to go with their Dual Battery tray and added a smart battery isolator. The battery setup I ordered isn't listed on their website, but it is basically the KISS system with a a different battery isolator. You can contact John Carruthers at Benchmark (425.417.7372) if you want to order the upgraded system.
Disassembly NOTE: This is one of those projects that requires an solid understanding of electrical wiring. Care must be taken throughout this project. One shorted wire could blow the Jeep computer or damage who knows what. You have been warned....
The first step is pulling the battery and getting the wiring out of the way:
Remove the electrical connector from the Evap Purge Solenoid
Remove the connector from the top of the battery box
Remove the battery and push the cables toward the engine and out of the way.
The next step must be done with care. You need to disconnect the TIPM module (fuse box). The only wire connector that you need to disconnect is the one on the outside facing toward the rear of the Jeep. Do NOT disconnect the connectors under the TIPM module!!
Then you need to remove the 4 10MM screws that hold the TIPM mounting bracket.
I don't have a good picture of this step, but you need to remove the factory air filter housing. This is easier than it looks. It is mounted with rubber feet. It pulls straight up and out. You just need to disconnect the intake tube coming from the engine.
Now it's time to remove the entire battery box assembly. It connects to the firewall with 3 washer nuts and goes to the front of the engine compartment. This is one big piece of plastic. To make removal easier, remove the power steering fluid tank first. It is removed with one bolt.
Remove the 3 washer nuts on the firewall, then disconnect the fender nuts, finally remove the bolts that were under the air filter.
Finally, you just have to remove the box. It is easy, but you have to be careful. It is easy to scratch the paint or cut a wire. Start by lifting in the front then twisting a bit. It will come right out.
Here's what it looks like with the box removed. Lots of space!
