Adventure EV

Archive for December, 2009

The Good, The Bad, and the Ugly

by on Dec.24, 2009, under Batteries, EV Land Rover, The Knowledge

Sorry for the gap in posts.  It’s been a very hectic couple of weeks!

Funding an electric vehicle conversion…  You’re not entirely alone here, depending on where you are.  It’s odd that there’s no real support for alternative fuel vehicle conversions at the Federal level, considering the country’s “green awareness” climate, but individual states, and sometimes even individual counties offer tax incentives for alternative fuel vehicles.  That’s good news.

Sometimes the programs are quite generous, but due to ongoing difficulties with state budgets most are being cut back quite a bit for 2010 and beyond.  That’s bad.

In order to take full advantage of one of these programs I need to have my Land Rover certified as an electric vehicle and registered before the end of 2009.  I’m also heading back to the east coast for the upcoming holidays.  It doesn’t leave me a lot of time to get stuff done.  That’s ugly.

Ahh, if that were all…

In order to ensure my shot at taking advantage of one of these programs, my Dad graciously booked a vehicle inspection in Broomfield, CO, just outside Boulder, CO, for December 17.  Broomfield is 350 miles away.  Ohhh, that’s bad.

And my batteries have been delayed from China.  That’s really ugly.

In fact, they will not get to me by the end of 2009, and that’s just sad.  But it is what it is.

Here’s the good.  Christmas came a bit early this year:

Of course those four, deep-cycle, lead-acid batteries weren’t just for testing the controller!  They were, in fact, part of my backup plan.  That’s my Dad driving, and me on the wobble-cam.  Sorry about that.  My budget on this one is all going into the build…

First impressions:  Torque from zero rpm is a very good thing.  The Soliton-1 motor controller is amazingly quiet, there is no high pitched whining as the motor spins up, only the slight whirring of the two small cooling fans.  The motor is amazingly quiet.  In fact, pretty much the only sound you can hear in the video is the tires on snow.  A Prius in electric mode makes more noise.

Colorado doesn’t care whether the electric vehicle is finished.  They just care if it’s an electric vehicle, and that means no ICE.

Motor Bay

Temporary 48 volt lead-acid setup while waiting for the LiFePO4 cells to arrive. No ICE to be found. High tech broom handle acts as bonnet stay.

So with a top speed of 20 mph and range of… who-knows-but-I-don’t-want-to-test-it, we loaded the Land Rover onto the back of a U-Haul auto-transport attached to my other Land Rover (a Range Rover) and towed the rig up to the Broomfield Technical Center.

Loaded Up

I was actually surprised how well the Range Rover handled the extra weight.  All told, it was moving about 10,000 pounds over mountain passes at 5000-8500ft ASL, and even then we managed to maintain 65-70mph most of the way and average 11.5 mpg with nary a wiggle from the rear.  How the H2 Hummer, which doesn’t weigh 10,000 pounds, achieves less than 10 mpg is beyond me.

New and Old

Don't worry about the Range Rover's sagging rear. Once on the move, the air suspension raises to keep everything level. The Series Land Rover has no idea what that means.

This is definitely one arena where ICE will win out over EV.  It’s not that electric motors can’t provide enough power (diesel locomotives, after all, run electric traction motors,) it’s that the amount of energy required to move 10,000 pounds at highway speeds for 350 miles is just immense…more than 15 times the amount of energy I can store in a single charge of my battery-pack-to-be.

Testing

So we made it to our appointment with the state tech inspection station (apparently my camera did not, as witnessed by the terrible phone pic), and the truck passed with flying colors!  I didn’t even have to drive it off the trailer, which slightly disappointed me, but who was I to argue…  They just checked the VIN number, popped the bonnet to ensure there was no ICE in there, and issued a document indicating that a new title with change of fuel status to electric be issued.  The guy at the inspection center was gracious, very helpful and mentioned that there were quite a few electric conversions in the Boulder, CO area, but no Land Rover’s that he’d seen.

Pass Screen

Screen at the testing center reads: "This vehicle has been converted to dedicated electric power."

The next day we applied for a new title and registered the car.  So it’s all legal now.  And it’s technically an electric car.  So I’m claiming a bit of success regarding the challenge of converting the Land Rover to electric power by the end of 2009.

It’s not done, of course.  I still have quite a bit to do to fulfill my original design goals.  Pretty much all the fabrication is complete, save for some small bits here and there.  But I still have to load in the lithium cells, and obviously that can’t and won’t happen until 2010.  I’m actually writing this stuck in an airport on my way back to the east coast while a blizzard rages.  I won’t be back to the project until next year.

Temp Setup

Chances are that I won’t really be able to complete the project until the spring.  The last few weeks have been difficult, a true learning experience, and ultimately satisfyingly fun, but I need to get back to working on some projects that pay the bills.

This is a good thing.  The weather will be warmer, and I’ll have a battery management system (BMS) design in place.  I can finish painting.  And, I can work out why my clutch only disengages 90% of the way, I suspect my motor adapter spacer is too thick by about a 1/16th to a ¼ of an inch.

But don’t worry, I’ll try and get some pictures of those lithium cells.  They should come in just as I get back in the new year.

So have a great Holidays, everyone.  Stay safe!

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Battery Box Update

by on Dec.15, 2009, under Battery Boxes, Controller, EV Land Rover, Fabrication, Heater

Did I already do a battery box update?

The one continuous thread throughout the conversion has been the fabrication of the battery boxes.  It seems these things take forever to build.  But it’s been cold… and I’m being whiny.  I must admit that they are pretty heavy duty, though.  Far more robust than they probably need to be, but probably beefy enough to handle off-road rigors, if necessary.  Like everything in this Land Rover, they’re built tough… very fitting.

Most people build a tray that the battery cells sit on, usually located somewhere in the engine bay, or more commonly, in the trunk.  I wanted to build sealed enclosures that sit completely under the vehicle, out of the passenger compartment.  Since I’m using lithium cells this shouldn’t be a problem.  Flooded lead-acid batteries, in comparison, vent hydrogen gas when they charge.  You wouldn’t want one of those in a sealed container…

There are four boxes in total, carrying 64 LiFePO4 battery cells.  Two sit on either side of the vehicle where the stock fuel tank locations were, just under the seats.  A larger rear box sits tucked up between the rear axle and rear frame crossmember.  The final box sits in the front of the engine bay.  All of it is made from 1/8″ mild steel in various forms; angle iron, square tube, strap, sheet.  Aluminum sheet is used to fill in the gaps and cut down on weight, but even with that saving measure I’m guessing all the boxes will add at least 150 pounds to the rig.  Not great, but they’ll last forever and be able to take some abuse.

Here’s one of the side box frames being held in position under the chassis by a Harbor Freight transmission jack.  Once full with batteries the jack will be the only way to get the boxes in place (the rear box will weigh about 260 pounds), a very worthwhile investment!

Side FrameThe rear box sits between the rear road springs and hangs from the rear crossmember.  Another piece of angle iron stretching between the frame rails anchors the front mount.  There’s a nice, empty space under the short-wheelbase Rover.  I had previous modified a Jeep fuel tank to fit back there.  Now the space is home to a different fuel.

Rear Frame

Crossmember DetailThe Rover has an unusually short rear overhang.  Great for off-roading.  I probably lose a couple of degrees with the rear box hanging down, but it shouldn’t pose a problem.  All in all, it’s quite an elegant fit.

Rear Clearance Since the top of the boxes are angle iron to provide strength and a lip to seal the top lid against, they pose an obstruction for the cells, so notches were strategically cut to allow groups of strapped cells access.  Not having the cells made this hard.  I just have to trust that the dimensions will allow for the clearance.

The final frames were painted with POR-15, and aluminum sides were cut to size.

Frames OutsideOK, granted the thin aluminum sheet isn’t exactly the toughest stuff in the world… But finally, something that cuts like butter!  And here’s the tool that does it.  Harbor Freight electric metal shears that make quick work of the box walls.  Say what you will about the quality of Harbor Freight stuff, but it’s cheap, and gets the job done for the few times people like me need something done.  And having the right tool for the job makes all the difference!

Shears

Once the sides are cut, they’re riveted to the frames.  A combination of the paint and sealing caulk ensures no galvanic reaction between the steel and aluminum, and helps seal the box from the elements.  Here’s Dad helping out with the riveting.

Dad Helping

A very nearly finished rear box.  I suppose I could leave it this way, but the plan is to spray self-etching primer on everything and coat with a semi-gloss black.  However, it’s been too cold to do any of spray painting.  All in good time.

Rear BoxI’ve sized the boxes to be slightly larger than the cells so that I can place some insulating foam around the perimeter.  This will help against shock and increase the insulation factor for the cold season.

The LiFePO4 cells should be fine just sitting in the cold, but they don’t like being charged in sub-zero weather.  To help performance in colder months, heaters are employed.  The bottom of each box gets two layers of aluminum.  One layer acts as the exterior wall.  A layer of foam (temperature tolerant Ionomer Foam from McMaster-Carr)  sits on that, and then thin battery heater plates from KTA Services, Inc sit on the foam.  These heaters are rated at 35w each and run off of 120VAC.  The idea is that these heaters will connect directly to wall power when the EV is charging in the winter.  As the cells discharge during normal driving, they should create enough internal heat to suffice without the heater pads active.  The second layer of aluminum sits on top of the battery pads, not only to protect them, but also to help spread the heat under the cells.

Heater

The hardest box to build was the front box.  I had originally designed the rear box to contain three rows of eight cells, for a total of 24 cells, but the rear differential pumpkin got in the way.  One of the rows of eight had to go, and in its place I got a compromised sideways row of three.  I had to find a place for five more cells.

The Rover does have a bunch of hiding places for more battery capacity, but rather than try and mount a fifth battery box, I decided to modify the front box.  It turns out space is becoming a premium if I want to keep everything moderately contained and relatively simple.

Instead of only needing to house 16 cells, the front box was widened to contain 18, and a small side box was welded to the back providing the space for the final three cells.  It’s weird, but it works as well as it can without the actual cells on hand.  I really hope I’ve left enough wiggle room.

The front battery box will have a clear acrylic lid for extra “bling-factor.”

Here’s the basis for the front box.

Simple Front FrameThe frame bolts directly into the frame rails.  Another set of brackets was fabricated to carry the bigger electronic items, the charger and motor controller.  The charger is another piece I don’t actually have yet, so I’m hoping the dimensions I found online are correct.

TrayThe charger sits a few inches above the motor, behind the battery box, and the controller sits a few inches above the charger.  The front of the “components” frame is bolted to the back of the battery frame so that it can be removed separately if needed.  The rear of the frame bolts directly to the vehicle’s bulkhead/firewall.

Once everything is tight the whole assembly ain’t goin’ nowhere.  It’s extremely solid!

Full Frames

Again, gotta love that access!  The Rover makes this conversion so easy in some ways.

Hopefully, all the miscellaneous electronics (fuses, contactor, shunt, relays, etc.) will sit behind the controller, up against the bulkhead.

Wait, I have the controller!  What’s that look like in place?

Electrics FinishedWhat are four, deep-cycle, flooded lead-acid batteries doing in the battery box?

Controller UpdateWhy, helping test out the motor controller, of course…  That’s an ethernet cable attached to the Soliton-1, with the controller’s configuration page on my netbook…

I can’t end the story there… can I?

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Motor Installation Complete!

by on Dec.09, 2009, under EV Land Rover, Motor Adapter, Motor Bracket, Tachometer Sender

Last we left the motor mount situation, I had welded new brackets to the frame of the Rover.

While the motor was out, and the bracket paint drying, I took the time to bore a 12mm hole in the side of the clutch bellhousing to house a proximity sensor used to generate a tachometer signal.  The motor controller can use this signal to discover how fast the motor is spinning in order to limit motor rpm for safety and longevity.  A tachometer also comes in handy when datalogging and giving user feedback.  I can use the tachometer to determine which gear to be in to optimize efficiency (there are other tools for this, as well, but motors like to spin faster rather than slower, within limits.)

Proximity Sensor

I also had to remove the flywheel to grind two notches, set 180 degrees apart, into the side.  The proximity sensor detects the presence of metal within 2mm of its face.  When placed 1.5mm from the flywheel edge, it will detect the presence of the flywheel.  When a 2mm deep notch rolls by the sensor doesn’t see metal anymore, breaks the connection, and that creates a pulse.  The circuitry in the motor controller and tachometer count the pulses, divide by two, and output motor revolutions per minute.

Proximity Sensor Installed

I used an AM1-AN-1A proximity sensor from Automation Direct for about $20.  It has three-wires and is shielded with a sensing range of 2mm.  They sell others that sense up to 6mm if necessary.  Of the three wires, one connects to a power source (10-30VDC, in this case 12VDC), the other to ground, and the third outputs the pulse signal.  Some proximity sensors require a pull-up resistor to provide a clean signal, though the tech at Automation Direct assures me that this particular model does not need one.  In order to easily set the distance, (when attached to a power source) the sensor is equipped with a yellow LED that will light up if the sensor is sensing something.  Very handy.

With the flywheel installed again, along with the clutch and clutch pressure plate, I maneuvered the motor into place in front of the transmission input shaft, and after much cursing and back tweaking, the two were  successfully connected.

I know, I know… it seems everyone’s EV blog has some video of the time the motor was first installed and run off a 12V battery to see if everything was working.  Yeah, my Dad and I did that, but it was late and really freakin’ cold, so I’ll save that tidbit for another day.  But the wheels did spin!

The only problem was that a leaking clutch slave cylinder (I should have know if the master was leaking the slave wouldn’t be far behind) meant disengaging the clutch was a no-go.  By the way, this was all done with the rear wheels off the ground… not toodling across the snow covered mesa.  A new clutch slave arrives tomorrow evening.  Hopefully the lack of full clutch control really is just the slave cylinder and an adjustment, rather than a miscalculation, by me, on the motor adapter side.

Now that the motor was fully mounted to the transmission, I could concentrate on attaching the motor to the new motor mount brackets on the chassis.  Glance into the way-back machine and you’ll find a photo of a round bracket assembly in two halves that I posted earlier.  Here it is again:

11" Motor Bracket

11" Motor Bracket

It wasn’t possible to attach the chassis brackets to a position in-line with where the round motor bracket would go.  So I came up with this bit of metal-jiggery:

Motor Bracket Modification

The round motor bracket halves cradle the motor, and 2″ x 3″ square tube was welded to the top half of the round bracket.  The square tube transfers the weight onto the chassis brackets via rubber-filled motor mounts, the same mounts used when the ICE was in place.  I realize that this puts quite a bit of stress on the union between the square tubing and the round brackets.  Again, hopefully the welds will hold up, as well as the metal stock.  Everything looks and feels beefy enough, though.

Motor Bracket Detail
Underside of top motor bracket
Motor Bracket Closeup
Bracket in place on rubber mounts prior to paint

Below is the final result fully painted and bolted together.  It can’t be seen, but there’s a 5/16″ Grade 8 bolt that connects through the upper part of the motor band to the lifting eye socket in the motor.  This should help prevent the motor from rotating under load.  Amazingly, everything aligned properly and the motor sits correctly!  I mean, I meant for it to be like that…

Final Motor Install

With the motor fully in place, I can now concentrate on the fabrication of the front battery box and the bracketry for the electronics that live under the bonnet.  Next time on… Adventure-EV…

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