DC-DC Converter Installed and Wiring Cleanup

I installed the DC-DC converter - the Azure Dynamics DCDC750 BC12 battery charging unit. First, I had to build a few cables. These are the high-voltage cables. The red Anderson connector actually goes to the heater, not to the converter. The black connector is known as a Yazaki connector - it looks like a better design than the Andersons (for one thing, it looks like it is waterproof - it has silicone seals).


Next, I installed the cabling. The thick 4 AWG cables coming from the battery are new. The unit puts out roughly 60 amps, so you need some pretty hefty cable to avoid a voltage drop and overheating / burning up cables. All of the cables are protected by plastic spiral wrap. In the lower left, you can see that I have installed some twisted pair wiring onto the Hall-effect current sensor - I'll have a full post later about hooking it up.


With the DC-DC in place, I decided it was time to clean up the spaghetti explosion. First, I installed a Power Pole to hook up the 12V battery to the original fusible links which run the electrical system. This replaces a bolt wrapped in electrical tape, which was not a good long-term design.


I also upgraded the wiring to the power steering pump. It pulls up to 60A. I previously had used 10AWG wire - about 8 feet in all. Using the calculator at this site, it showed a likely voltage drop of nearly 1V - which translates to about 60W at max power. Which is a full lightbulb of energy going through a fairly skinny wire. Which could then burn up. Also, this would restrict the power of the pump. I upgraded to 4AWG, which should be plenty adequate (both the positive and negative sides were upgraded).


Finally, I spent quite a lot of time routing cables into looms and making things neat and pretty with zip ties. I still have not permanently mounted these two relay boxes. Going to have to do that soon...


Next up - cleaning up the routing of cabling into the passenger compartment, and, hopefully, starting to hook up the dashboard.

Power Brakes and Stuff

I squeezed in a couple of miscellaneous things today. I got the vacuum pump for the power brake assist hooked up. It is *loud*. Imagine one of those aquarium pumps you had as a kid. Bzzz. Now imagine ten of them. BZZZZ. I'm looking into mufflers or other options (wrapping it in bubble wrap as shown had very little effect). You can see that the wiring has exploded into spaghetti - soon it will be time to attach everything and put all the wiring together into looms. But for now, it works - I took my wife and oldest daughter for a ride around the block now that steering and braking are not such a pain.


I did get a start on attaching things. I mounted my two high-voltage power poles in the front compartment, directly above the DMOC. The red thing in front of the most positive pole is a Hall-effect current sensor. I decided I did not like the idea of a shunt-style ammeter at 312+ V. This is the sensor for the Shoreline Ammeter:


I also put together an enclosure for the high-voltage fuses protecting the 312V voltmeter and heater. Also in this enclosure are a relay to turn the 312V voltmeter on / off with the keyswitch:


I updated the circuit diagram to include the relay and to show the Hall-effect sensor instead of the shunt:

As always, you can find the PDF here.

Power Steering!

Today was Power Steering day. If you may recall, last year, I bought an electric power steering pump kit from CanEv. I fiddled with a few things, making a rack to mount it on, but never got it hooked up. I finally got a high pressure hose crimped at my local Parker Store, but other projects got in the way. But finally I got it put in.

Here is the pump, mounted in its home. The thick red wire gets power from a relay and circuit breaker. The thick black wire goes to ground. The black hose with green stripes is the high pressure hose that goes from the pump to the steering box. The thinner blue hose is the low pressure return line from the steering box to the fluid reservoir. The thicker blue hose goes from the reservoir to the pump.


Here is the reservoir, tucked in a corner near the most negative battery in the pack. It is not permanently mounted yet - it's just kind of resting there. This obviously needs to get fixed before driving... Here you can see the three hoses I discussed earlier:


Here are the electronics which turn on the pump. The box on the left is a high power (100A) resettable circuit breaker. The box on the right is a high power relay. The relay is turned on when the key switch is turned on, causing the power steering pump to run. This is all shown on the 12V circuit diagram.


Also this week I have been doing some battery tuneups. The charger I had been using to top off the batteries was clearly inadequate - it never got the voltage up above 14.1V, and the whole pack was dragging at around 12.4V - 12.5V per battery, giving a total pack voltage when "fully charged" of around 318V. The worst thing was that the battery levels were pretty far apart, making bulk charging a risky proposition. So, I got a pair of higher-tech chargers that claim to be able to desulphate batteries - BatteryMINDer:


They actually seem to work well. I have not given any of the batteries the desulphation treatment yet - I'm going to let them all rest until Monday morning and see which ones have sagged the worst. But, as you can see, the fresh charge gets up very close to full now (where "full" is roughly 330V for 26 12-volt batteries):


Next up - power brakes... and cleaning up the rat's nest in the front compartment.

He's baaaack...

After a hiatus that turned out to be much longer than expected, I'm back at it. This weekend was the first chance to actually do anything - I had to get the garage cleared out after the Voltwagen insanity.

First thing I did was mod the hood. It had not been closing very well with the top on the front rack. So, I took a Dremel cutoff wheel to it and surgically removed part of the support (the grey splotches are primer to keep it from rusting):


Next, I finished the interconnects in the front rack. Six months ago (!) I was in a big hurry to try to get it kind of running so it could move in and out of the garage. So I did not put the heatshrink on the interconnects, nor did I have the PakTrakr fully attached. That has now been corrected:


Finally, I got the charger re-installed. You may remember that it died a few months ago and I sent it in to be repaired. I never did figure out what killed it - my best guess is that a transient voltage spike killed it. Don't know where the transient came from - turns out I had a flaky AC plug that was sparking when plugged / unplugged - maybe that was it? I've replaced it the plug.


A few things of note on this picture. First, I also installed a kilowatt hour meter from EKM Metering (just like on the Volt914) so I can track wall-kWh-per-mile. Second, inside that gray box the meter is sitting on is a 12V power supply. This will provide a few things - a light that shows on the dash when the Jeep is plugged in; and a relay that will tie a signal to ground to tell the controller not to run when it is plugged in. Eventually it may control other fun 12V systems that are needed when it is plugged in. Third, I've provided a ground to vehicle chassis (black wire in foreground) per the Manzanita Micro instructions.

Lastly - next to the gray box - you can see that I have replaced the 5/16 bolts with longer 3/8-16 bolts for the rear hold-down. I was not convinced that the 5/16 bolts were heavy enough. And I could not get a good grip on them with the nuts - they were not quite long enough. So I drilled them out (a lot of fun - hardened hex cap bolts do a number on drill bits) and put stainless steel 3/8-16 bolts in their place, held down by wing nuts.

Short list of things that *must* to be done to make it safe / really driveable:

• Hook up power steering
• Hook up power brakes
• Replace instrumentation (especially speedo)

Short list of things that *should* be done before it is driven regularly:

• Install DC-DC converter
• Replace some of the dual 2-gauge cable interconnects with triple 2-gauge interconnects (makes it equivalent to 2/0 gauge)
• Bolt down some loose electronics boxes in the engine compartment
• Put in the add-a-leaf kit for the rear suspension (it is sagging quite nicely...)
• Get the clutch working (hook up hydraulics, fill & bleed)

And there is a nearly infinite list of things that can be tweaked after that, including big items such as 4WD.

Brief Hiatus

I'll be taking a brief hiatus from the Electrojeep over the next 3-4 weeks - I'm building a 5/8 scale model Benz Patent Motorwagen and putting an electric motor in it for a local theater group. You can follow my progress at the voltwagen blog.




See you back here in a month or so!

Declaring Victory and Moving On

I finally got some time and good weather today to finish up the motor install. Although I had some back-and-forth with helpful blog readers, I decided to stick with my current plan for now. I'll re-examine the motor mounting this summer to see whether anything is being stressed by this design.

Here is the motor from the top. The side bolts have blue thread-lock applied, and are torqued to 80 foot-pounds. In addition, there are washers exactly filling the space between the forks and the cradle to reduce the torsion about the motor mount bushings:


After placing the front rack and batteries, I jumped up and down on the front bumper a couple of times to settle the springs, then took this picture. There are now roughly 4 inches of clearance between the motor and the front differential:


As I said at the beginning, this is not probably the very best motor mount - a torsion bar of some sort between the two forks would be very helpful, as would additional bolts between the forks and the cradle, but it will be adequate for now. I'll consider a rebuild this summer.

Pumpkin Interference, V

Man, this motor mounting project has turned into a pain... This week, I finished the motor mount I had designed last week. I cut it, welded it, bolted it, painted it, and installed it on the motor. When I went to install the motor, the trouble started... but let's step back in time first. Here are the original parts, all primed pretty:


The bolts are torqued down to 25 foot-pounds per typical specs on Grade 8 hardened steel bolts. The primer is just rattle-can metal primer. The welds are there to keep everything aligned more than for structural purposes - the bolts themselves are plenty strong to hold everything together. The two longer parts I call the "cradle" since it cradles the motor feet. The two shorter parts are called the "forks" for obvious reasons (they go around the motor mounting bushing).

I finished painting the parts (rattle-can black) and mounted the cradle on the motor. The 3/8" bolts holding the cradle on were torqued to 45 foot-pounds, along with some blue threadlocker. Those guys won't come off unless I want them to. The forks are temporarily mounted for photogenic purposes. The handy thing about the cradle is that it provides a good place to loop chain or cable around for lifting with a hoist:


And here is where the trouble began. I'm not sure how, but I measured the distance between the two motor mount bushings incorrectly. I measured it at 19" - but it is really closer to 18.5". This means it is impossible to mount both forks at the same time. In this picture, you can see that I have mounted the passenger's side fork, but that the whole motor is pushed over toward the driver's side about one quarter to one half an inch:



Because of this skew, I could not install the driver's side fork. So, I put a temporary bolt on the driver's side just to support the motor while I went back to the drawing board (this is obviously only a temporary measure):


The good news is that there is sufficient clearance between the highest point on the motor mounting system and the bottom of the front battery rack (so at least I measured *something* correctly):


After much thinking, I came up with a new design. The issues were:

• The current design is too wide
• But I can not make the fork tines shorter while still using box tube because the main 1/2" bolt head will interfere with the motor mount bushing retainer
• Additionally, the box tubing on the fork "tines" was too thick to easily get a nut onto the bolt that goes through the bushing
  
• And, I'm not happy using threaded rod - I'd rather use a grade 8 hardened steel bolt thru the motor mount bushings, and those typically only come in 6" or less lengths (unless you special-order them).
  

I finally realized that I could do three main modifications to the fork design:

• Replace the long box tubing with an angle iron
• Shorten the tines by 3/4"
• Cut the tines in half at the motor bushing bolt end to make more clearance for bolt heads etc.

So, I did it. Here is a rendering of what the completed motor mount will look like with the modified forks:


Here is an exploded view of both the driver's side cradle as well as the new driver's side fork:

And, I built and painted the new forks. Installation will have to happen some time this week or next weekend. I'm out of daylight...


You may find a PDF of the blueprints for the driver's side motor mount (both the cradle and the fork) here. Note that the passenger's side is a mirror image of the driver's side.

All this for a stupid front differential... if only I could have found a two-wheel-driver front axle and transmission...