Friday, May 29, 2015

Van Build: House Battery

Now that the bed and fridge are special ordered, I thought I'd start on the House Battery set up. This forum has really great resources on the different options, and how to-s. The different products that are out there really will make your head spin. Since I opted not to do a solar array, I chose a rather basic configuration. I went to NAPA and got about 30 feet of #2 red wire and a $30 battery isolator. Then it was to Amazon to order some Blue-Sea goodies: Blue Sea Systems 6007 m-Series (Mini) Battery Switch Selector, 3 Blue Sea Systems Class T 225 to 400A Fuse Blocks with Insulating Cover, 3 Blue Sea Systems 225A Class T Fuses, and one Blue Sea Systems PowerBar Dual BusBar with Two 3/8-Inch 16 Stud and Insulator. Sam's club had a screaming deal on deep cycle batteries Energizers 29HMs. Then I visited our friendly local metal vendor for some 3/8 thick 1 1/2 x 1 1/2 angle iron.
Research told me that the most common place for auxiliary batteries to be installed is on the frame rail between the body and side loading door cargo step. Ford even puts the extra Diesel's starting battery there. Using the batteries for measurements, I welded up a battery bracket assembly, then checked and rechecked the tolerances between the floor and the top of the batteries. I could use one hole that was already drilled, but had to drill three more holes in the frame.
I then cut some wire at various lengths using a die grinder to start building the isolator and switch panel, as well as the wiring to wire the two deep cycle batteries in series. A ground wire was added from the batteries to the stock ground wire already located on the chassis.
So the idea here is to run the wire from the starting battery across the cowl to the first fuse block, then into the Blue Sea switch position 2, then run wire from position 1 to the isolator input. I then ran a wire from the isolator output back to the switch in position 1+2. The final wire to the house batteries is installed to the output of the isolator. The idea here is with the switch position to '0' the system is physically isolated, the switch in position '1' is electronically isolated, the switch in position '2' is isolated physically too, but position '1+2' is physically connected. So you can either use the isolator, or the switch as redundant systems. The beauty of '1+2' would be if you needed a battery boost should the starting battery get too weak, or to charge the house batteries should the isolator fail.
The wire from the isolator then runs to another fuse block close to the house batteries and installed on the rail. The third fuse block was installed just after the house batteries, also on the rail. If there were a dead short the fuse closest to the battery would blow then isolating the batteries from the system.
Seeing the photos helps make more sense, I hope. Some additional research told me that the batteries sitting in the battery bracket assembly shouldn't be allowed to flop around. I've heard cases where the batteries jumped up and struck the floor over big bumps. My solution was to use some wire cable and turnbuckles as battery tie downs, as you can see in the image. I had to use two floor jacks to lift the batteries into position, then grade 8 bolts and nylon lock nuts were used to secure the deal.
Now the batteries do hang down below the frame, but not any further than the transmission cross-member, and still above the bottom of the running board. Since I have a short wheel based van, I don't think clearance will be an issue. Looks like were good to go...

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