Thursday, October 1, 2009

Rudman Mk2 Disconnects

For my AGM batteries, I purchased Rudman Mk2 Regulators from Manzanita Micro. The regulators will sit outside the battery boxes in little boxes of their own, with fans to keep them cool and transparent tops so I can see the lights flashing. This means, though, that I need a disconnect system so I can service the batteries when needed. The disconnect will also serve as an easy way to charge individual batteries if needed.

After some Googling, I found the disconnect I wanted - Metric-Pack 480 sealed interconnects from Delphi. Waytek Wire has everything I need - the male/female housings, the male/female terminals, the silicone seals, and the strain relief clips. You do have to order many of the parts in multiples of 50. Oh, well. I'll have leftovers for some future project. I also got some 10 gauge wire. The crimpers are from previous projects - one is a standard crimper for solderless terminals, the other is designed for Weather Pack / Metric Pack crimping:

The Mk2 manual says that the wires connecting the regulators to the batteries must not show more than 10 millivolt voltage drop at the desired ampacity. I want to be able to bypass up to 8A, so that means 15 inches of 10 gauge wiring. I cut them to 14.5 inches because the interconnects add some length / resistance:

For some reason, I had the urge to consume some licorice at this point. Anyway, the next step was to crimp a faston to one end and a ring terminal to the other end of each wire:

I could theoretically have stopped here - I could have just used the faston as the disconnect. However, all those metal ends are just screaming, "Short me! No, short me!" and I did not feel like blowing up my carefully constructed wires or setting my car on fire. So, I cut all the wires in two parts. The short part is 4 inches long, leaving the long part at roughly 11 inches:

Here is how a Metric Pack 480 disconnect is assembled. The little purple things are silicone seals which go over the wires. The metallic terminals crimp onto the wire and the seal, and then the wire/terminal is inserted into the housing. A strain relief clip then goes on to finish it off. I took this picture before I had decided that the *short* wires would be female - the male connector is a good 2.5 inches long and would have taken all the slack of the short wires - I need a little slack...

First, you slip the seals on, before stripping the wires:

Next, you crimp the terminal over the wire and seal. There should be a little bit of wire showing on both sides of the wire crimp. GM recommends soldering at this point. But I'm lazy.

Here are all the female ends crimped on:

About to insert the female ends into the housing:

Ta-da! All done, with the strain relief clip attached. Kind of pretty, I think:

Here's a close look down the business end of the female disconnect:

And here are 18 complete female disconnects. The stripping / crimping is the time consuming part; snapping the disconnects together goes very quickly:

The male is just about the same. Here you can see the length of wire to strip and how it should fit in the crimp area of the terminal:

Here is the crimper in action. You put the top of the "A" on top of the crimps, and the tang pushes the terminal up into the concavity, folding the little crimps over very neatly. I only had one mis-crimp out of 72 crimps - and that one was because I got over-zealous on crimping the silcone seal and I tore it:

Here are all the male terminals crimped on:

And here is a complete housing (but without the strain relief clamp):

A look down the business end of the male disconnect...

And here is the complete male and female disconnect clipped together:

And here is the whole mess - 18 male and 18 female disconnects:

I did some sketching, and the 11 inch length of the male ends should be plenty to get outside the battery box for all the batteries. I also plan on making a couple of battery charger female disconnects. But my hands are tired, it will wait for another day.

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