Thursday, September 6, 2012

Days away from a drive

There are a lot of connections that go into wiring up an electric car (so I have found).  A lot of progress has been made over the last week or so and we are coming up to the exciting part where power is applied to the system and a test drive is clearly in sight!

In the time since my last update a safety shutoff switch that has been mounted in the dash which is wired in series with an inertia switch that's now mounted under the hood of the car.  This will be connected directly to the contactor to apply pack voltage to the controller and give me the piece of mind to be able to disable the traction pack from within the car and also in the even of a collision.  I was able to replace a toggle switch in the dash in place of a toggle switch that is no longer necessary.  This gives it a real factor look and feel inside the car.

Don't mind the extra wires hanging out of the dash.  Those belong to the radio!

I have gotten a few extra parts which have not only enhanced the safety of the system but also improved the aesthetics and physical layout within the car.  In my original design I had only a large fuse and contactor to isolate my battery back from the rest of the system.  This would leave me in a tight situation if my contactor failed (as in welded itself shut).  I picked up a large maintenance switch which allowed me to run my positive pack voltage into a single input and then place my fuse box one of two output posts.  I used the second output post on the switch to run to my charger.  This cleans up the connections considerably and makes everything under the hood flow.  It also allows connections to be traced through easily through the system.

From the above images you can also see my mounting system for the DC/DC converter.  I mounted an aluminum plate onto the secondary mounting bracket of my charger and attached the converter.  This will allow for easy access to the connections and offer improved cooling as it gets the converter into a position with plenty of airflow around it.  The entire assembly is mounted to a larger aluminum plate which fits over the previous gas tank frame.  This leaves a large air pocket under the plate which should aid with cooling.

I'll step back for a moment and illustrate the guts inside the fuse box.  Originally the positive pack cable ran into the box through a single large fuse through the contactor and out of the box.  It also has a bridge from the fuse to a coil and a smaller fuse that is designed to run out to the DC/DC converter.  I decided to bring a JLD 404 into the system and so I had a need to apply a shunt to the system.  I moved a few things around and used a 60 mm battery bar to mount the shunt in series between the large fuse and the contactor.  It's a little tight in the box now but everything fits!

Before shunt
Correction...Don't put your shunt on the positive side of your battery pack.  it will damage your meter.  Also note that the white wire pictured on the left side of the contactor is actually suppose to be on the right so the DC/DC converter does not run constantly even when the car is off.
With all the components nestled nicely under the hood the main traction pack cables were pulled through the car and to the controller.  I used six gland nuts to protect the cable as it passed through the aluminum plate and then again through the firewall of the car.  Finally another set of gland nuts were put in place to exit the rear firewall of the car to allow connection to the controller.  Something to note is that when running the cables it was necessary to run them without the crimped ends on the cable as they did not fit through the gland nut caps.  Fortunately this was discovered right away and did not cause any problem when pulling the cables through.

Cables coming through the front into the cabin
Exit point for cables out to the controller.

Controller connection point (rubber caps have been added since this photo)
Next work day for the car is Saturday!  Hopefully after a few more hours it will be a ready for a test drive!  I'll then start buttoning up loose wires and putting some loom around exposed wires to clean things up a bit.  Look for another update next week with some video footage of my hopeful test drive!


  1. Hello Caleb. I too am converting my 69 Beetle to electric. We have basically the same kit from Rebirth Auto. I'm using the Kostov 10" and 40 130Ah Calb cells. I went with the Kostov because i didn't need to cut the rear apron. Fits like a glove. A very tight glove. The Super Beetle appears to have so much more room in the front than a standard. There's no way i could get 30 cells up front. I'm running 15 up front and 25 behind the rear seat. Needless to say the back end of my beetle is riding a tad lower than i'd like. Any suggestions on how to get some added ride hieght in the back? I've taken it out on the road a couple of times but i don't have any windows in. I had the whole car repainted before starting the conversion. I'll try to get some photos and perhaps a video or 2 online for viewing. Good Job.

    1. Hello, The beetle is a excellent conversion vehicle with its easy to access transaxle. I did end up cutting the rear apron on the car but it didn't really need to be cut. I will need to drill a hole to retain the rear output shaft and shave off some of the inner lip but other then that the apron will fit back on without and issue. I decided to do my conversion before working through the body work so that any wholes I created or scratches it got in the process could be taken care of after it was running. I may put a new rear apron on the car anyway as I'll be eliminating the exhaust pass through.
      You are also correct about the extra room in the front of the Super Beetle. It's about 4 inches longer in the front and they went from a vertical spare tire to a horizontal which sat just under the lip of the gas tank. They also moved to a McPherson front end from the torsion bars in your beetle. This eliminated quite a bit of vertical intrusion into the trunk space allowing me quite a bit more room to work with.
      I have exactly the opposite problem with the rear end on my car. I don't have the rear seat installed anymore and the motor/controller don't weight as much as the original engine so it's sits very high. I would much rather have to bring it up then try to lower it. I don't have a ton of experience with suspension work however, I understand the rear end can be equipped with coilovers which would supplement the original horizontal torsion bars and give the added height. The other option (one that I may be pursuing) is removing the arm from the torsion spring and drilling 4(maybe 3 in your model)new mounting holes to bring the rear end up or down. For your situation the added resistance of a coilover may be a better bet as the extra weight will stress that rear torsion suspension and you may start to see the sag again after a couple years. Good luck with your build. I'd love to see some pictures or video!

    2. After some further digging it appears that you can unbolt the rear torsion arms and make fine adjustments to either tighten or loosen the rear. Be very cautions if pursuing this as there is a lot of force in those torsion bars. There are two adjustments on the inside and outside of each torsion beam. The inside one is for major adjustments and I have read that for each spline of rotation on the bean it's about 1" of vertical increase or decrease. If I am able to get to this in the next couple weeks I'll put up some additional detail of the amount of work it takes.

    3. that's exactly what I'll be working on this weekend. Need to purchase some replacement bushings first. Did you make the battery box yourself? At the moment I'm using angle iron frames. Ugly! As for the shunt you put in the fuse box, I thought the battery monitor needed to be on the negative side of the pack. I created another fuse box with a fuse, shunt and contactor connected to the negative side. Not exactly sure why it needs to be that way, just following the directions. All of this is a learning experience.

    4. The battery box I had built by a local metal shop. It's made up of 1/8" aluminum plate and fits the batteries perfectly. It ran about $300 but with the space I was mounting it it was well worth the cost. As for the shunt your absolutely right. I stated installing things before I read the documentation on the JLD404 intelligent amp hour meter. You have to run the shunt on the negative size. I have corrected my installation error since this post and now have the shunt mounted prominently in the center of the plate just above my maintenance switch. It appears that the meter needs to be run off the negative side because it cannot switch the polarity internally on the meter. I should have read more carefully before I jumped in and added it to the positive side of my system. Good luck with your suspension adjustment! Do you have a site or blog with info on your build?

    5. Did you put together a schematic for your system? I asked the guys a Rebirth Auto to send me the diagram. What I got back was a hand drawn schematic on graph paper. Works great though. I decided that I was too lazy to mess with the torsion bar adjustment. So, I decided to put on coilovers. It worked. The car is nice and level now. I drove it down the street and back this weekend. Very exciting. I have not installed the liquid cooling yet for the controller. As soon as i tried to get past 35mph the controller derated. Not a problem as i was just staying in the neighborhood. The kit should arrive this week. Hopefully in enough time to install over the weekend. I also went down to my local boat supply shop and picked up some DC components. Battery disconnect like the one you have installed and a Aux bat gauge. Which brings me to another point. I was looking at your connections again and it appears to me that you have the positive end of your pack going into your fuse box in the wrong direction. If you send me your email address I'll send you the pics I got from Rebirth for the connections.

  2. That's great that you have it on the road now. I'm glad the coil overs worked to bring the back end up on your Beetle. I don't have a liquid cooling system on my controller yet either. I was kind of waiting to see how it handled the air cooled application. I typically get up to 40 in second gear and it holds pretty well there with my 96 volt system. As for the fuse box I have nearly completely reworked the way it's running. When I took these pictures I hadn't tested anything yet and so I didn't really consider things like the DC/DC running all the time. The connections I have in the box now have the large fuse on the pack side that goes directly to the contactor and on the controller side of the contactor I have my DC/DC converter wired up to run similar to an alternator. The charger I don't have fuse protected in the circuit as I currently have it connected through my maintenance switch which goes directly into the pack. I'll be tweaking things a bit as I go as this is my first build. I would really like to see the schematics Rebirth Auto sent a long. Although they labeled everything pretty well it was not always clear what really went where. I have a rough outline of how I wired everything but I don't think anyone else could really read it but me right at the moment. You can email me at



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