Just Wow!

Not to be confused with J-Wow!

Driving around with the new battery pack this week. Initial thoughts....

Wow! Losing 800+lbs of weight makes a huge difference. The Vue now accelerates much quicker and brakes easier.

Wow! Less energy used. With the old pack I was using about 400w/mile. With the new pack the combination of more efficient batteries and less weight dropped the energy use. Initial figures show this to be between 300-330w/mile.

Wow! Greater range. Today I took the Vue for a 40 mile drive. With the old pack this would have been the limit of the range, on a warm day, with a fresh pack, and sluggish performance at the end. With the new pack the fourtieth mile was just as good as the first mile. And based on the amount of energy used max range is between 85-95 miles.

Wow! Move over Nissan Leaf :-)

Just glad the winter is over

It's now been two years since I've converted a 2002 Saturn Vue from gasoline to all electric. Other than a few minor hiccups, as previously documented, the Vue has been my daily commuter five or six days a week. It now has over 10K electric miles on it.

This winter was a little tough for using the Vue. Everyone who has ever driven a regular car in the winter knows that the starter battery isn't quite as "peppy" when it is cold out. Well lead acid batteries in electric cars are just as finicky about the cold.

On a nice hot summer day, dead empty for my two year old batteries is probably about 35 miles. This poses no problem since my round trip commute is 20 miles. (My wife continually reminds me that it is only 13 miles if I don't go out of my way to get coffee. But it's really good coffee!)

Anyway, I digress. During the winter my range drops to about 20 miles. That means for my 20 mile round trip I need to charge at work in order to make it home. No problem. I have an outlet behind my office. Eight hours is more than enough time to recharge to full.

So my winter routine is drive to work 13 miles one way. Charge eight hours during the work day. Drive back home 7 miles. No problem at all....except for the snow.

You might be asking yourself what does snow have to do with electric vehicle range. My answer would be nothing. Except for when it comes down....and down...and down.. and down...for a total of about two feet over a couple weeks.

You still might be asking what does that have to do with the car? Roads get plowed and the Vue is front wheel drive. So that's not a problem. And the car has a great electric heater. So that's not a problem. What's the problem?

Glad you asked:-). The problem is that all of that snow has to get plowed somewhere. And the guys at my office complex decided that the best place to plow it was in a corner...behind my office...where the outlet is located :-( Yep, several feet high and deep of rock solid plowed snow right where I need to plug in.

I thought about trying to dig it out but then the second shoe dropped...more snow. And this time the outlet wasn't the problem. You see I have to plow the snow in my drive somewhere. And after all the snow had been plowed as far off the drive as possible the only place left for me to plow it was in front of the garage bay where the Vue is stored :-( So now not only couldn't I recharge at work, I couldn't even get the car out of the house!

Luckily the snow melted, the garage door unblocked, the plug visible, and the Vue back on the road for the last several weeks :-)

Just lots of acronyms

To everyone following this blog (all two of you, you know who you are) I apologize for not posting for a while. I'm sure you have been waiting with bated breath and were in the midst of going into withdrawal :-)

I haven't been posting, but that doesn't mean work has not been progressing. Currently I'm waiting for some wire to arrive. It is on back order.

In the mean time I've been working on the instrument cluster. Until I started taking the instrument cluster apart I didn't realize how few of the original cluster lights and gauges I could get rid of. Here is a picture of the original cluster.


The obvious gauge I wouldn't need was the fuel level. Some people actually do keep it and use it to track battery state of charge. I have another gauge for this so out it goes. Same with the engine temperature; no engine to temperature :-)

There are a bunch of lights indicating various engine conditions: too hot, change oil, service, battery, low coolant, etc. These would be sacrificed.

In the end there are only a few things I wanted to retain: tachometer, speedometer, odometer, turn signals, high beam indicator, and night time cluster illumination. In addition I will be adding a new gauge that lets me monitor battery voltage, battery amps, amps used, amps remaining, and a few other things.

This is the exploded view of the cluster.


In the old days each light and gauge in the instrument panel (I/P) would have dedicated wires. Vehicle speed sensor (VSS) to speedometer, crank position sensor (CKP) to tachometer, etc. Now a days cars have several computers collecting and dispensing information. Two of these are the engine control module (ECM) and body control module (BCM). They talk to each other and the sensors via a controlled area network bus (CAN Bus).

So the VSS sends its signal to the ECM. The ECM converts the analog VSS signal to a digital signal and broadcasts the information over the CAN. The BCM hears the VSS signal broadcast on the CAN and retransmits it to the I/P. The I/P then has a chipset that signals the speedometer needle to move.

They say that going from the analog way to the digital way saves 30meters of wire and decreases the car weight by dozens of pounds. It also makes "hacking" into the car electronics a hell of a lot harder. Oh for the pre-acronym days :-)

So here's the I/P circuit board. The four big white things are the four gauges. The bulbs are for the turn signals and I/P illumination. The little, rectangular white spots are LED's for all the warning lights.


Now I need room to fit the new gauge that keeps track of the batteries and motor. It has two parts, a display and a dial to select different display functions. Here is the display portion. The selector dial is a little smaller.



I decided that the best place to place the display was where the old temperature gauge was located. There were a few LED's there that I would not need. So after cutting out the unnecessary circuits and mounting the display I have this:



Next I had to do the same thing for the selector dial. The old fuel gauge on the far left was a good place. I also soldered a few wires to some LED"s to use as indicator/warning lights for the controller. This is the rear of the board after everything was mounted.



Here's what the front looks like.


On the left is the selector dial stem. On the right is the new display. I painted over the old markings where the thermometer was located. I need to paint over the old fuel gauge markings.

Next step is to get the I/P working again. I installed the I/P back into the dash and powered it up. The turn signals work (they are the only thing on the I/P that is directly wired and does not go through the CAN). The I/P illumination also works.

As expected most of the LEDS no longer work since I cut through the portion of the board that contained their circuitry. As for the speedometer and tach testing them will be a little tougher. I need to reconnect the ECM since the VSS provides data to the speedometer via the ECM.

The tach is a little tougher. Since I removed the engine I no longer have a crankshaft or a crankshaft sensor to provide data for the tach. I do have a sensor that will provide the new motor RPM's. I plan on connecting the new sensor to the ECM in place of the old sensor. Hopefully the new signal should satisfy the ECM. If not then I'll just pull the old tach and get an old fashioned analog one as a replacement.

Just fishing

Fishing in this case refers to routing wires from the front of the vehicle to the back. Since the charger and the majority of the batteries are in the back of the car there needs to be a way to connect the components in the engine bay to the components in the rear.

To accomplish this I constructed a conduit made of PVC pipe. The conduit is fastened underneath the vehicle in the approximate position of the old exhaust system. Through the conduit multiple wires will be routed.

I've pulled through most of the smaller wiring. The next step is to pull through the "big wires".






The picture above is where the exhaust pipe ended in the back. I'll connect this to one other piece (seen from inside the vehicle below) in order to get the wires into the battery box.

Just $0.35 vs $200.00

The title of this post refers to the cost difference between fixing vs replacing a part. A little background first.

While disassembling the car I had to detach the shifter cables from the transmission. These cables connect the "stick shift" inside the car to the transmission. The cables translate the motion of moving the shifter to actual gear shifting.

In the process of removing the cables from the attachment to the transmission I ended up snapping the plastic bushings that connect the cables to the transmission. Here is a picture of the snapped bushing.




There is another part to this bushing that is not shown. It is a hollow half sphere made of metal that sits in the center of the bushing and snaps onto the transmission shifter.

Here's the bushing attached to the transmission. You can see the bottom arrow points to where the bushing is still attached. The top arrow points to where the bushing has been removed (and the little ball it snaps onto).


The cable fits over the bushing. You can see the eyelet where the bushing would go through.



So when this happened it was no big deal. The cables were undamaged. The transmission shifter was undamaged. All I needed to do was go to the dealership and get the replacement bushings. How much could they cost? :-(

The answer to that question is $0. You know why? They don't sell them separately. You see, Saturn has decided that if these break you have to buy the entire set of cables. Then remove the old set and install the new set! And how much are these cables? Over $200 (and that's the cheaper aftermarket price).

So now I have a dilemma. Do I spend $200 for something that can't cost more than $0.50? And if I don't how do I fix this?

Well my first inclination was to check the internet groups that discuss the Saturn Vue. I can't be the first person this happened to. Sure enough I was not. Apparently these bushing break frequently under normal use. Unfortunately no one had a good answer for fixing them. The best solution I could find was to cut off the metal ends where the cables attach, drill a hole and tap it. Then I could insert a bolt to hold the cables in place. Not the solution I was looking for.

My second thought was to find another manufacturer, application, or device that used the same type of bushing. Then I could modify it to work for me. Again no luck. These bushings seem to be unique.

The next idea was to find another Saturn Vue in a salvage yard and "harvest" the parts I needed. And that was where I was headed until I decided to create my own bushing.

So I ended up buying stiff polypropylene tubing the same diameter of the bushing. I then cut off a piece the same length as the bushing.


Next I drilled several holes in the tubing to insert cotter pins. The plan was to trap the neck of the shifter (below the ball) between the cotter pins. Total cost...about $0.35.

Here's the result.


Running through the gears the shifter works fine. The ultimate test will be how it holds up. Luckily with an electric motor shifting is at a minimum. Only time will tell.

Just a quick post

Now that the racks are completed I've started laying out the components. Here is a picture from the top.


The grey box on the right is the low voltage fuse box. The small green box next to it is the Hairball (the brains of the controller). Under the two is a large grey box holding the high voltage fuses.

On the bottom right is a black box. This is the car's original fuse box. The big green box with the dinosaur on it is the Zilla. The Zilla is the high voltage part of the controller. The silver/blue boxt next to it is the DC converter for supplying power to the 12V circuits. Not shown is the vacuum pump (for the brakes), the water pump (cooling the controller), and the hot water heater (passenger compartment heat).

Just another update

When last we spoke or at least when last I spoke...actually when last I wrote...scratch that. When last I typed!

When last I typed I had just finished laying out the front battery racks. That was last weekend. This weekend I finished installing the racks.

Here are pictures of the top rack. It will hold four batteries.




Since my welding skills are non-existent the racks are bolted into place. First holes were drilled into the chassis and rivnuts fastened to the chassis. This basically makes the hole threaded in order to receive the bolt. The racks were then bolted into place with 3/8" grade 8 bolts. The cross members were secured with 1/4" bolts to the supporting members.

Since the chassis is not a flat and level in the engine bay some shimming of the racks was required in order to keep the racks level. One inch nuts and fender washers made great shims.


The lower rack was attached by 6" bolts through the frame. No rivnuts were needed since the bolts protruded through the chassis.


Per the last post I was planning on putting nine batteries in front. The two racks above hold seven total. The last two were going to sit in a rack between these two and close to the level of the lower rack. Unfortunately I'm about 3/4" of an inch short in space. I could put one more there and then one more in the back. But I think I'll put two more in the back since I have plenty of room there and use the extra space for the auxiliary 12V battery and other components.

Just polyhedrals

This weekend was battery box weekend. Or should I say battery polyhedral weekend! You see, the rear cargo area is not a regular shape.

Now I could put a regular shaped box in the cargo area. But I'd be losing a lot of the nooks and crannies to put batteries. So instead of fifteen I could only fit in twelve. To maximize the space I need the "battery polyhedral".


The downside of this design is that it has almost twenty sides including tops and bottoms. And all of them need to be cut to size.


Now cutting this isn't too bad except I don't like butting the joints together. So for extra strength the top and bottom have rabbit joints for extra support. Which explains why it took most of the weekend to cut these pieces.

Next step. Epoxy paint, assembly, and cutting holes for vents and wires.

Oh and one other thing. The battery layout has changed again (hopefully for the last time).

Just playing with my rivnuts...see pictures below

Don't get too excited :-0

Since the last post I finished connecting the rear battery rack to the vehicle. Most of the rack is connected by 3/8" bolts and locking nuts directly through the sheet metal. Here's a picture of the bolt through the top.



And here's the bolt, washer, lock washer, and nut on the underside.


This arrangement worked great for the majority of the rack. There were a few places where the rack needed to be connected but was not accessible from under the vehicle.

This is where the rivnuts come in. Rivnuts are blind rivets that accept a bolt. You drill a hole, place the rivnut through the hole, then compress the rivnut around the sheet metal.

This is a picture of an uncompressed (right) and compressed (left) rivnut.


You can see that when compressed the rivnut forms a collar. This collar traps the sheet metal and secures the rivnut. The inside of the rivnut is threaded and accepts the 3/8" bolt.

In case your wondering about the strength of the rivnuts they were originally developed for holding airplanes together!

Just breaking in (not breaking) the motor

Today I took the motor for its first run. Technically it is a "stay still" and not a run since the motor stayed in place :-) I guess the proper phrase would be that I took the motor spindle for a run (or at least a fast walk).

Below is a picture of the motor hooked up to a battery charger. The charger is acting as the power source. I was going to take a video. But the spindle turning was exceedingly boring (according to Ari).


The last of the lugs and fuses came in so I started crimping the lugs onto some of the wires. Crimping involves cutting very thick wire, stripping the insulation to expose the ends, sticking the ends into lugs, crushing the lugs to trap wire, then putting heat shrink at the junctions.

Here's the wire so you can get an idea the thickness of 2/0 wire.

Here's a wire with two lugs on the ends. The wire is the big black thing hooked up to the motor.



I also started laying out the components of the high voltage box I spoke about before. I changed the layout a little from prior. This is the new drawing.



And here's the components as I start laying them out.

Just the adapter

That should be, "All I'm waiting for is just the adapter". Thanks to the arrival of the electric motor today.

Just the batteries...battery...sort of

Even though I have scale pictures for placement of the batteries and components I need to make sure things will fit in real life. It's tough to take accurate measurements in the engine compartment with the engine still in it. With the engine bay empty it's easier.

The engine compartment is not a regular shape. There are nooks and crannies where things once were. There are irregular hoses still in it (like the brake master cylinder and hoses). I want to make sure that I have enough room. So tonight was mock up night.

This is a rough sketch of the engine bay. There are a more nooks and crannies then this shows, but you can get an idea from this.


Based on the fact that the transmission is going back into the same place I have a pretty good idea where the motor will be mounted. Below is where I think it will be.



So now it is time to fit in the batteries. I want to use 24 batteries. I can fit 15 in the cargo area without folding down the seat. So I need to fit 9 in the engine bay. You would think with a big empty engine bay that should be easy :-)

Now before I go any further I should show you a battery...sort of. This is a picture of a regular car battery next to a scale model (note the craftsmanship in the model) of the batteries I will be using.



As you can see from this picture the batteries I'm using are big (slightly less than one foot long, one foot high, and 7" deep). They weigh ~62 lbs each. Here is a preliminary picture of the battery placement.



Looks pretty good, right? So I go into the garage with my handy, dandy life size battery model (a.k.a. ugly white box) to see how this will fit.



Well you remember those nooks and crannies I was talking about? Let's just say that the layout above won't work. So I spend about an hour and a half in the garage with this white box. Moving it this way and that way. It's sort of like a 3-D puzzle. Finally this is what I end up with.



This is still preliminary as I have to wait to install the motor and transmission to be sure that they will actually fit. But I'm pretty confident this layout will work. Of course I was pretty confident the first layout would work too!

One final note. I got news that the motor should be arriving on Monday...by freight...all 180 lbs of it. Hope Ari (my son) does not have a soccer game that night :-)

Just preparing again

Now that the car is mostly disassembled I'm waiting for the motor and adapter plate in order to start reassembly. Till they arrive there is lot's of "little stuff" (little meaning not 500lb engine stuff) that needs to be done.

One of the little tasks is putting together an enclosure for the some of the high voltage components in the system. This enclosure serves both as a convenient way to mount the components and as a safety measure.

The components are:

Fuse



The purpose of the fuse is to disable the power and protect the components "plugged" into the battery pack in case of a short circuit or malfunction. The fuse is equivalent to the circuit breakers in a house.

The traction pack is composed of twenty four batteries for a total voltage of 144V. The pack is capable of delivering over 300amps. So this is one big #!& fuse! (For comparison most modern houses are supplied with 120V, 200amp electric service.)

Shunt



In a gas powered car there is instrumentation that informs the driver of the status of various vehicle operating parameters. This includes the fuel gauge (how much fuel is remaining) and the trip computer (how is my gas mileage).

An electric vehicle requires similar instrumentation in order to know how much energy(fuel) is remaining in the batteries and how many miles/watt (miles/gallon) are being used by the vehicle. The shunt is the component that lets that instrumentation "tap" into the battery pack in order to measure some of the above parameters.

Contactor



In a gas powered vehicle turning on the ignition switch starts a series of events that eventually leads to fuel delivery to the engine. Ignition switch closes circuit----relay in starter motor closes---starter motor turns engine---relay in fuel pump closes---fuel pump delivers fuel---combustion occurs in cylinders.

In an electric vehicle the electricity (fuel) is delivered to the motor by closing a switch between the battery and the motor. The contactor is the switch that closes this circuit.

High voltage fuses
Several other components of the vehicle, besides the motor, require electricity. This box also contains the fuses protecting the individual circuits for these components.

Below is a schematic of what it should look like once assembled. Later in the week I'll stop by the electric supply store to pick up parts for the connections.

Just musing over the next step

Today I did some little stuff on the car. Pulled the remainder of the fuel lines, removed a few pieces of stray hardware, and salvaged a few pulleys from the old engine.

Now that the majority of the demolition is over it's time to start on the harder part. Putting it all back together.

As you may have guessed the electric motor has to be attached to the car somehow. Specifically it needs to be attached to the original transmission. But this motor looks completely different from the engine that was removed. So how do you attach the two together? The answer is an adapter.

The adapter that I am using is custom part. It needs to be fabricated from aluminum or steel. I thought about machining it myself. That would involve buying a mill and tools to make the adapter components. It would mean learning how to mill the parts. And since the parts have to be precise (to the thousandths of an inch) it would mean a lot of trial and error. Given all of that I figured in the long run it would be better for me to farm out this part to a machine shop.

Electro-Automotive is a vendor of electric vehicle components. They make adapters for just this application. If they have previously made the adapter for the make and model of your vehicle they can make it easily. If not then you have to ship the transmission to them so they can make a pattern.

I was lucky in that someone else is/has converted the same vehicle. So they have the pattern in stock. All I have to do is send them a rubbing of the original transmission and flywheel. That way they know that they have the correct pattern. (Sometimes manufacturers change parts mid year so two cars that are supposedly the same may actually differ.) Below is the rubbing.



The original engine was bolted directly to the transmission. The two were designed to directly bolt together.



Not so with the electric motor. Since the motor and transmission were not designed to match an adapter needs to be fabricated that bolts to the motor on one side and the transmission on the other side.



In addition to attaching the motor and transmission, the drive shaft of the motor and transmission need to be coupled. In the original car the engine's drive shaft was attached to the flywheel.



Power is transmitted to the transmission when the clutch plate and flywheel are in contact.


With the electric motor the drive shaft will also be attached to the flywheel. In order to accomplish this a coupler needs to be fabricated. The coupler consists of a bushing and a coupling plate. The bushing is "squeezed" onto the motor drive shaft. A coupler is then bolted to this bushing and the flywheel bolted to the coupler.



Here's a blowup of it all.