June 2011 Randy’s Electrical Corner - Jp Magazine

There are a lot women out there and it can be hard to pick the right one. Now I’m not an expert at women, but I hear that when you find the right one you just know. I never thought too much about it. I figured when the right woman found me it would be like a rock dropped on my head or my foot or something and I’d just know. As it turns out, there are a lot of dual battery setups out there too. From the simple switch through remote-switched solenoids up to and including complex micro-chip controlled setups, it can be hard to tell which one is right for you. When I saw the IBS dual battery kit on the Sierra Expeditions website, I just knew, and I think I can relate to all of you love birds now.

june 2011 Randys Electrical Corner randy Photo 32471692

The expedition thing means those guys are relying on their vehicles far from anything, so they need good stuff. The electrical stuff on Sierra Expeditions is really good stuff. The company has relays, lights, circuit breakers, and more. I just like browsing the site to see what neat things there are. Plus, whenever I order something it shows up quickly. The company has other things too, but you know me, I’m an electrical nut. So, when I saw the Intelligent Battery System (IBS) from Extreme Outback Products, I was confused. I’d never heard of it before. It provides a display to see what condition each battery is in all the time, eliminating the guesswork that most dual batteries require. If that wasn’t enough, it monitors the voltage of the system when charging and automatically charges both batteries when the Jeep is running. This is something I should have known about. Then I saw that it was made in Switzerland and that Sierra Expeditions is one of the only companies here carrying it and I didn’t feel so bad.

So I talked the wise old Jp editors into giving me two pages just for this month so that I could get my hands on this cool new dual battery system. Once it showed up, I decided to put it in the ’91 Comanche that I put the jumper cables in a few months ago. I apologize to all you Wrangler guys out there, but I will add in a few Wrangler tidbits as I go. As for you Comanche and Cherokee guys with the inline-six (’87-’01), much of this will be right up your alley. If you have done a dual battery kit before, this one isn’t terribly different. And if you haven’t done one before, let ol’ Randy give you some tips and tricks on how to do it.

june 2011 Randys Electrical Corner jeep Engine Photo 32471695 PhotosView Slideshow For any dual battery kit, you will need to mount the second battery (duh). In an MJ or XJ that gets kind of interesting because there is no unused underhood space like in a Wrangler or CJ. The factory air intake sits in a spot opposite the factory battery that makes a great spot for a second battery. So the factory air box needs to go away. My solution was to use this cowl-induction intake kit from Trail Head Off Road. It relocates the air cleaner to the cowl where the windshield wiper linkage is. This gets it out of the way of the second battery, makes it much harder to suck in water, and draws in cold air for a power boost. The IBS is very complete as delivered. It includes the controller, a 200-amp relay, all necessary connectors, two new battery terminals for the new battery, and 10 feet of plus and minus 4-gauge battery cables. I added a pair of Odyssey 34M-PC1500 batteries as well. The battery in the truck was dated 2004 and was fading rapidly. The Odyssey has 880 cold cranking amps and 135 minutes reserve capacity. They are made in the USA and I got them from West Coast Batteries who have good prices and offer free shipping on them in the U.S. The IBS system does a great job of monitoring the status of both batteries. However, it needs at least 10 volts on the second battery to be able to self jump-start if the main battery has died. So, I ordered this Relay Booster Module (RBM) upgrade as well. I don’t plan on ever running the second battery that low, but better to be safe than sorry. This RBM will allow connecting both batteries together all the way down to 3.3 volts. I know the Jeep won’t start that low, but I do know that I have started some with as little as 9V before. Also, it will automatically start off the second battery if the main battery drops below 10 volts. Wrangler NW Power Products markets very strong metal battery trays for all kinds of Jeeps and is one of the only games in town for the XJ/MJ. The company also stocks high-quality wire and connectors. On a Wrangler, 10 feet of cable would have been plenty because the batteries are mounted right next to each other. On this thing it wasn’t enough, so I ordered extra wire along with some connectors and heat-shrink tubing to help me complete the job. At 2½x4x1 inches the control/monitor box can be hard to locate, but it is worth it because of the real-time monitoring it offers. In the pre-’97 XJs, where the factory clock was mounted is a great place to put the box. It is out of the way, yet easy to check. The individual displays are much more informative than the factory gauge because the charging system and battery levels are separated. That makes fixing any problems down the road easier to figure out. I had heard that the system was waterproof and the rubberized electrical connectors sure seemed to agree. I pulled the 200A relay apart to see if it was coated inside and it wasn’t. Sure, it appears to be made of a very high-end copper conductor, but it isn’t coated so any moisture that gets in will start it down the path of the Statue of Liberty. So, I used some silicone when I put it back together. You can see the RBM on the left is fully sealed. If being made in the USA wasn’t enough for you to pick up an Odyssey, there are a few more things that make them stand out. Most batteries can only do either high-amp starting or work for long drain periods (such as running a fridge or a light). This battery can kick out 2250 amps for up to 5 seconds and can be drained up to 80 percent for at least 400 cycles. Like most spiral-wound batteries the Odyssey uses dry cell AGM plates, but because they are flat, the battery is filled with 15 percent more charge-carrying plates versus the same-sized spiral-core battery. Note how well it fits in its new home. Even with the silicone sealing the relay, I wanted to mount the RBM and the relay as high as possible to minimize the amount of water that gets to them. Even with the silicone the relay might leak and keeping electrical stuff out of water is always a good idea. Be careful how you route the wires, as a lot of amperage can be going through them (and, no, a circuit breaker isn’t a good idea here). Because of where I put the relay and RBM, I routed the wires around the back of the engine bay. Running them across the front would have been easier and shorter, but it would have put the wires too close to the fans and in the way for removing the front clip, which happens a lot on these Jeeps. Even though the IBS included connectors, I soldered everything I could to make sure it could never work loose. I also used some liquid electrical tape to seal the connections from the elements. I didn’t use it on the battery connections because they get removed and cleaned from time to time. If I listened to instructions, at least the negative would be removed at every oil change, windshield washer refill, and maybe even gas stop.