If you know me I try to get everyone I know and some I don’t know, like people waiting in line at the grocery store to build a 72 Hour Bag for their car in addition to having an earthquake kit at their home. I try to get everyone to understand they may not be home or may not be able to get to their earthquake kits at home so having one in your car is just as important. If your car becomes disabled then you will most certainly need to rely on the items in your car. But if your car can move and get you home it is perhaps more important to not have to use your 72 Hour Bag at all. I mean the point is to get home safe right? Well this past week I took steps to ensure that my vehicle will get me home even in adverse conditions. My FJ cruiser has space in the engine compartment for a second battery. After a couple of weeks of research my fellow FJ owner, Jack and I figured out a schematic wiring diagram which we mostly ripped off from the Dirty Parts shop specializing in four wheel drive parts and accessories for FJ cruisers.
What we did was install two 250 amp fuses to separate the two batteries and put them on either side of the solenoid which you can see in the two pictures below. We used a yellow top AGM – Applied Glass Matt battery, which are the safest batteries you can use because the are sealed and will not leak even if run upside down. These batteries have additional ports which can be utilized if you need more power for large electrical devices.
The solenoid controls where the power comes from to start the car. Below you can see the switch below my HAM radio. I can utilize both batteries, battery A or in Emergency mode start the car from battery B.
In addition to installing the battery we added a separate fuse panel which controls all additional electrical items such as my HAM radio, External lights, winch, etc. With this additional battery installed I can be sure I’ll be able to start my vehicle in an emergency situation and have the power needed to operate my additional devices with out ever compromising my primary factory installed battery.
Jack and Johnny Pinstripes did a great job fabricating and installing the dual battery system. They wanted to install the system to be just as good as the kit sold by Dirty Parts but do it for less money and they successfully achieved it. It’s just one more thing I can add to my list of items prepped for an emergency situation. Hopefully I’ll never need to use it in an emergency but I know it’s there. At the very least it’ll be great to have on a four day four wheeling adventure.