Monday, August 18, 2014

EVCCON 2014 - Day 5

This is the last official day of the show.  A group of people and several cars went just south of Cape Girardeau to Dyno Dom's Sikeston Dragway.  This is a 1/8th mile NHRA official track, so any fast times set here go into the record books.  Last year Jack's speedster set several records, and we were hoping for good things with John Metric's Miata dragster.

First up was the TVR but about a quarter of the way down the track it went bang and came to a stop.

And here they're pushing the TVR onto the trailer.

This is what the driveshaft looked like after all of that torque.

Next up was the triple AC35 motor with titanium shaft 911.  Lots of power, lots of money!

The 911 then ran against a beautiful hand-built AC Cobra replica.

A beautiful blue electric pickup truck was up next.

To everyone's surprise this electric drag motorcycle showed up for the racing.  He wasn't an EVCCON attendee, but came because he saw that today's racing was sanctioned by NEDRA.  He holds the world record for his voltage class, and you can see why.

This highly-customized electric golf cart (but still with the original gearbox) also holds the world record for its class.

Jason Horak's "Daytona That Wouldn't Die" survived the week of EVCCON without blowing up any parts.

Jack Rickard's Speedster Replica is one of the fastest street-focused home-built electric cars around.

Now we have the 911 vs. the Speedster in a Porsche grudge match.

Then the one we were waiting for all week - John Metric's custom electric Mazda Miata drag racer against the 911.  At the end of this run, the front hood peeled off the Miata and flew into the woods on the right side.

There were also a few gasoline motorcycles on the track that day, but we didn't pay much attention to them, they're so noisy and smelly!

So that wraps it up for EVCCON 2014.  See you next year for EVCCON 2015 from September 29 to October 2015, and if we're lucky there will be an EVCCON Amsterdam sometime soon.

Saturday, August 16, 2014

EVCCON 2014 - Day 4

Today is the last day of presentations, then we go outside for the car show in the park.

First Session - Built It To Last and Build It To Maintain It.  The Myth of No Maintenance Electric Vehicles by Brian Noto

EVTV's very own co-host "The Brain" has spent many hours building, rebuilding and rebuilding again electric cars, so he's in a great position to discuss component choice, build technique and maintenance.

Jack jumped in and discussed the battery situation of the electric Smart car he just bought on eBay.  You can lease a Smart electric car and included in your monthly payment is a battery lease fee.  You can also buy the car and then you also own the battery too, but they still want you to pay the battery lease fee.  They will sell you a new battery pack, but it costs more than the price of a whole new car.  Jack got in contact with the president of Smart USA who promised him the CAN bus documentation so Jack can build his own battery pack for the battery-less Smart be bought on eBay.  We'll see what happens after he talks with the engineers and the lawyers.

There is a growing issue that you can buy a car these days, but you can't fix anything yourself because of a lack of documentation, and more and more of a modern car is embedded computers and software.  Most car companies won't release their specs and that hurts us when we try to understand or update the vehicle we've bought and paid for.

Brian talked about other OEMs that we in the world of electric cars came to depend on like A123, Azure Dynamics, Winston, Netgain Controls, Better Place and my own issues with PakTrakr who are now history.  The issue is someday the company you're depending on may go out of business.  This leaves you without a source for components, replacement parts, service and documentation.  This is the heart of the Build vs. Buy argument that every company has when sourcing components.

We should be moving to more robust and sophisticated techniques and components, like one-twist battery box disconnects rather than running cables through holes, and readily accessible components for replacement like controllers, fuses, and contactors, because things break and you will need to fix or replace.  Due to the high voltage and current, it's important to use hydraulic crimpers on your battery cables, and invest in a good crimping tool for the other wiring in the car.

Quality usually costs more, but do not compromise your car for short-term savings.  Also take time to research components and techniques, don't rush into decisions.

Fred Behning made a point of thanking EVTV for the excellent documentation that comes along with the products they sell.  The JLD404 and the GEVCU are especially good.  Jack recommends having a quality multimeter and sunglasses.  If you can measure it, you can tell if it's working properly.  Brian says to build a small team, each person with specific skills.  Jeff Southern says to get to know your local trade schools.  The point was made about watching the EVTV guys make a mistake, recognize it, make a new plan and succeed - this is how we learn best.

The questions was asked how many people are doing their own electric conversions.  EVAlbum has about 3000, but it includes electric bicycles and couches.  While other people think we are on the bleeding edge and doing impossible things, we think it's just a fun project and then we just drive it around to get to where we want to go.  Jack's theory of publishing is make people go away, and then you're left with the people who are intensely interested in the subject.

Next Session: Helwig Carbon Products with Tom Brunka

Tom recapped his fascinating sessions from previous EVCCONs.  Refer to my notes from EVCCON 2011 and 2012.  He did mention that he built custom brushes and thick shunt wires for John Metric's drag car.  The plasma you see on his videos from yesterday is generated at the point where the brushes touch the motor's commutator.  Without high-amperage and high-temperature brushes, they would self-destruct and probably take out the motor too.

One point that Tom stressed again, that most people don't understand, is that you have to seat your brushes before full power is applied to the motor, i.e. driving it for the first time.  The brushes come from the factory with the contact surface perpendicular to the side, but the brush is rubbing against a round commutator, so enough brush material has to wear off to get the brush into full contact with the commutator.  Tom's rule of thumb is, depending on the grade of the brush, is running the motor at 3000 rpm for between 7 and 17 days.  Yes, a week to almost 3 weeks, 24x7.  This ensures the brush is in full contact with the commutator, allowing maximum current flow across the largest area and lowest temperature.

Next Session: The Future As I See It - Jack Rickard

Jack and Paulo discussed the blitz build of the Smart car.  It was stuck in 4th gear on the first attempt but they got that fixed and it's now fixed in 2nd gear, giving fast acceleration and 55 mph top speed which is great for around-town driving.

Jack then brought us of the Smart car project up on stage, we introduced ourselves and talked about what we worked on.  Jack will have to top it next year, many people called out "boat" so we may have a floating project next year.

Next year's EVCCON 2015 is September 15 - 21, 2015.  It's a little cooler and more predictable good weather.

The boat that Anne built for Jack was supposed to arrive during the show, but is taking a week and a half to make it 300 miles from Chicago by Monday so most of us won't get to see it.  Boats and cars are just two kinds of vehicles that can benefit from electric motion, and even cars are highly specialized for the needs of their drivers.

Jack reiterated his view that all innovation comes from one or two people in a basement or a garage.  We are working in an area that still has incredible opportunity for great ideas.

Ray suggested we have access to a computer where we can copy on pictures and video and others can copy them back off.  Somebody else suggested Flicker.  Jack's looking for a volunteer to handle this next year.

Jack says the Lear company is quietly taking over the world of chargers in EVs and its CAN bus properties are a mystery that needs to be documented.

We now break for lunch then outside for the car show, as long as it's not pouring rain.  And we lucked out, not a drop of rain.  There was a gas car show going on on the other side of the park, so we got some visitors who wandered over from there too.

This is a Twike.  It has pedals and an electric motor and batteries too.

These are the two fastest cars at the show.  The front car holds the world record as the fastest golf cart.  Just behind is John Metric's drag racing Miata.

Hanging out in the back seat of Jack's Tesla Model S.  Well, it's actually Jack's wife Jill's car...

The Model S always had a big crowd.

Closeup of the dashboard.

I easily found my building in Thailand on the satnav, it's the L-shaped white roof in the center.  Unfortunately it wouldn't let me click the Navigate button.  It must have figured out you can't drive from Missouri to Thailand.

After the car show, we went on a very quiet, police escort parade through town.

At the end of the parade we got the cars set up for the traditional group photos.

After the group photos we got dressed up in our finest and had the closing banquet and awards ceremony.  I won the trophy for the furthest traveled attendee!

EVCCON 2014 - Day 3

Today was "fun day" at the Cape Girardeau airport, inside and just outside Jack's hanger.  Since the day is mostly pictures and video, just enjoy.

Jack owns two DC 3s, two helicopters, a biplane, a LearJet and a number of MGs that all still run on liquid fuels.  Maybe someday we'll convert a DC 3 to electric?

This is the cockpit in the DC 3.

Here are the passenger seats in the DC 3.  Much more comfortable than today's planes!

Here's his Huey.  His daughter Jennifer is a certified helicopter pilot.

The next series of pictures are some of the cars lined up for weighing before the drag racing started.  This is a 1960s Datsun pickup truck.

This is the custom-built "Seven" car that came second in the Progressive Automotive X-Prize competition.  They would have won but their clutch blew up in the acceleration test at the end.

A hand-built AC Cobra replica, a TVR and Fred Behning's MG.

This is one of the few new second-generation Toyota RAV4 electrics.  This has the Tesla battery pack and drive train, a product of their technology partnership that has now been dissolved.  The blue thing on the back requires some explanation.  It's a VW Beetle with the body and front wheels stripped off, so it's now a self-powered trailer.  When he's cruising down the road, he turns the RAV4's lights on, and this causes the Beetle engine to start, pushing the RAV4 and trailer down the road.  When he sets the cruise control on the RAV4 and the trailer pushes faster than the car is set for, it goes into regen mode and actually charges the battery as he goes down the highway.  When he taps on the brake, the Beetle engine shuts off.  He drove all the way to Missouri from Utah in this manner and actually used it on his dragstrip runs.  Unconventional, yes.  Wile E. Coyote ingenious, yes!

Nabil's Bradley GT, the quintessential kit car of the 70s, now in full electric mode.

The Mazda Miata makes a great conversion platform - light with great handling, and the transmissions can handle strong electric motors.

The Karmann Ghia in the morning sun.

Jeff Southern's VW Thing.  I got a ride home to the hotel one night in it and we stopped at CVS.  One of the checkout ladies had to run outside and check out the Thing.  He gets that a lot!

Miata, pickup truck, Miata, Jack's Porsche Spyder and Jack's Porsche Speedster, all electric.

All lined up, ready for drag racing to start.

I named this Swamp Thing.

John Metric's world record Miata.  He recently did a segment for MotorWeek, the PBS car show and it should be aired later this fall.  Check out his dyno videos below.

Under the hood, twin 2000 amp Zilla controllers.

This is the business end of a converted 911 from Montreal.  That's 3 HPEVS AC35 motors connected together with belt drive.  The motors were updated with titanium shafts and cases.

This is the inside of the motor controller in the newly completed Smart car.

And here is the Smart, completed and driven over to the hanger from the EVTV workshop.

The Smart now has a JLD404 meter in the coin shelf on the left side, and a state of charge meter in the original round housing on top of the dashboard.

Wednesday, August 13, 2014

EVCCON 2014 - Day 2

Today is the second day of presentations at the A.C. Brase Arena.  We look forward to tomorrow at the airport for drag racing and autocross and dyno testing, then Saturday for 3 morning sessions and the car show in the park.

First Session:  EV Technologies And Racing Applications - Adam Clark and John Metric

Adam and John kicked off by showing their drag racing plasma video I posted yesterday.  Adam and John are leaders in the field of electric drag racing.  They met and decided to build a drag racing Miata and they've set a couple of world records and always beat the gas guys!  Their car is called Assault and Battery, best 1/4 mile time is 8.9 seconds at 149 mph, the fastest car with doors in the world.  Don Garlits is a legend in top fuel drag racing and has come over to the electric side, which is bringing a lot of attention, trying to be the first to hit 200 mph in an electric dragster after being the first to go 200 mph in a gasoline dragster.  John Waylan's car is called White Zombie.  His youtube videos are legendary.

Electric motorcycles are getting fast, 0-60 mph in less than 1 second, 0-200 mph in 6.9 seconds!  The fastest motorcycle at Pikes Peak in 2014 was electric.  The Nissan Deltawing car raced at Le Mans this year, along with the Drayson racing car.  Formula E is a new open-wheel racing series sanctioned by the FIA, the world motorsports leader, and I will be attending the second Formula E race of the season in Kuala Lumpur.

As with conventional racing, a lot of the innovations trickle down to smaller racing series like SCCA and into road cars, and we expect that technology from electric racing will make it to electric road cars too.  Advances in shedding weight by using lighter and stronger materials, advances in battery capacity and power delivery, supercapacitors, controllers, motors, and software for control and data collection will make our road cars better in the future.

Since motors are so key to racing, Adam went into great detail.  Series Wound DC can go very fast for a short period of time, so they're good for dragsters.  Heat and brush wear limit their more general use.  Brushless DC are more suitable for smaller vehicles like go-karts.  AC Induction motors are good for larger vehicles by choosing the desired torque curve.  They run higher voltages which improves efficiency to 95% but the controllers are more complicated and expensive and can't yet offer the power needed for drag racing.  Permanent Magnet AC motors are a little more efficient and a little smaller and lighter than induction AC motors but will demagnetize if they get too hot, so beware.

A study was done comparing AC induction and Permanent Magnet styles.  In the city test, the PM motor was 27% more efficient, but in highway use they were equivalent.

Popular DC racing controllers include the Zilla 2K with 2000 amps at 380V, the Shiva is 3000 A at 425 volts.   AC controllers include the Scott Drive and several Curtis units.  To get more power, you have to increase volts or amps, or cool the units better.

Where do the business opportunities lie around electric vehicles?  Material Science is a key job for the future, trades such as welding and machining, software development, carbon fiber, aerodynamics, energy management devices like DC-DC converters.  Lonestar offers their own DC-DC converter and AC motor controller with 1400A continuous and 2800A burst, up to 1200V in, up to 1.5 megwatt output!

Next Session: AC Drive Systems by Brian Seymour of HPEVS

Brian's father started an electric motor business by rewiring broken motors for friends and family, and the business has taken off.  They got into the golf cart business and pioneered the use of AC motors.  Brian's generation moved into motors for electric cars, delivery trucks, boats and other vehicles.

Brian converted a waterski boat from a gasoline engine to a newly developed stainless steel motor called the AC35x2, containing two motors on the same shaft and oil cooled.  They also supply mounting plates and couplers to Mercruiser drives.  It has dual Curtis AC controllers and 144 of CALB's new CAM72 batteries.

HPEVS offers a wide range of AC motors, either single or dual units on a single shaft.  Some of the motors are air cooled, but most are water cooled now, for the future they're moving to oil cooling.   They're using Dielectric transformer oil, which is really good at getting into contact with every part in the motor and carrying away the heat.  Water cooled motors are just jackets around the hot parts which can't carry away all of the heat.  It also acts as a lubricant for bearings and seals, and allows for higher operating temperatures.  The impact of using oil rather than water or glycol has an impact on the pumps, hoses and radiators used in the cooling loop - they need to be selected for oil and expected temperature.  Mercruiser hoses are readily available, and oil pumps can be found at Summit Racing.  They suggest using the existing automatic transmission radiator.  They've also added an oil filter for safety.

Brian then showed a video of a ride in his boat, nice and smooth and quiet!  He then walked us through the performance charts.  The big takeaway is that his boat was consuming just over 10 X the watt-hours/mile as we would expect in an electric car of the same weight.  This is why you should plan on a very large battery pack in your boat, or take short trips.  Note that getting up on the plane is key to minimize hydrodynamic friction, but there is a big power penalty trying to go past.  At 42 mph, the motor was pulling 1,000 amps!  Changing the prop to hit your target speed at the sweet spot of the motor will minimize your power consumption at your desired top speed.  The weight difference is a net gain of about 100 pounds, so it's almost equivalent of stock.

Next Session: High Performance from Stock Parts, Part 3

A followup session to the first this morning from John Metric, President of the National Electric Drag Racing Association.  John crashed his car last week doing an interview with MotorWeek on PBS, but was calmer than now standing in front of our friendly group.

This is an update from last year's talk.  He uses twinned Warp 9 motors like I have in my little 914, but he's pumping an insane 2000 amps of current through each, using Lithium Cobalt pouch cell batteries.  The batteries he uses have doubled in output current in 4 years.  He hasn't used a BMS for 1.5 years but is still interested in monitoring the each cell, since he only has 30 minutes between runs at the drag strip.  He's built a device that plugs into his pack and gives a quick view of the health of each cell, highlighting the high and low cell in the pack.

He showed several graphs overlaying battery pack performance and controller capability, showing where they match up nicely or are over or under capacity.  He then showed some simulated dynamometer graphs with torque, rpm and horsepower curves.  Air is a real performance problem, with enormous increases in horsepower needed to overcome drag.

What John learned about acceleration of a drag car, is the weight of the car and the road surface coefficient of friction is all that matters.  Torque and horsepower don't even come into the equations.  Another big factor is twisting the chassis due to the spinning motor, he was raising only one tire off the ground, so you have to pre-load the chassis so the car is flat as it's going down the track.

If you want to be entertained, find some youtube videos of electric drag racing!

Next Session: and Electric Boats by Anne Kloppenborg

Anne is the face of EVTV in Amsterdam.  He builds cars, converts boats and is a major EV component supplier for Europe.  He sends Jack a video update nearly every week, so you can keep up with his efforts by watching EVTV.  They've grown so much they're moving to a much larger space about a kilometer away in October.

His first build was a Glastron ski boat, and then moved to boats with less weight and more efficient hull designs.  They then did a Nedcraft Silverback, a beautiful boat.  Then they did the Ray Wright Delta with two drive train revisions.  Now they're working on a cabin cruiser.

He showed the design and construction of the New Delta, which is the basis for the boat that Anne built for Jack.  It's somewhere on the road between Chicago and Cape Girardeau right now.

They're working on a Jeep conversion in the shop right now, and have built a set of adapter plates that and reduction drives that will allow them to mate any supported motor to almost every boat.

One big issue they've run into is the need to pass very strict electrical interference certification testing, which happily they did for their DC motor system, and recently submitted the AC solution, working together with competing companies in the area.  Unfortunately they overheated a resistor but it was an easy fix.

Anne has a goal of crossing the English Channel with an electric boat.  The Guinness Book Of World Records has, at the request of his friend Al Gaida, created a new category of Fastest Crossing Of The English Channel By An Electric Boat.  They will make the attempt early next year.

We are now transitioning to a general boat panel session.

They discussed the cost of ownership vs. gasoline, electrical noise in the wiring, the motor required for a large Amsterdam tour boat, reduction drive belt power handling, converting a personal-sized watercraft and details of the channel crossing.

Next Session: JLD 505 with Paulo Almeida and Celso Menaia

Paulo and Celso are instructors at an engineering institute in Portugal.  They are circuit and circuit board designers and came up with one of the latest versions of the GEVCU boards.  They are also the team leaders on the flash-conversion of the Smart car this week.

In their spare time, they've developed what they're calling the JLD 505.  This is their take on a Chinese device called the JLD 404, which is very popular in the EV world as it not-very-accurately measures voltage, current, amp-hours and watt-hours and controls two relays which are triggered from thresholds you can set.  It has a large blue LED display with buttons to scroll through the various values and is attractive to install in your dashboard.  It is key to determining the state of charge of your pack which keeps it healthy and gives you as the driver the information you need to avoid running out of juice on the side of the road.

Paulo and Celso are introducing to the world the first prototype version of the JLD 505.    It offers a better display and data output.  Their design protects the internal components with a fully isolated power supply, USB port, Bluetooth and CAN bus, two digital inputs, two digital outputs, current-measuring shunt and pack voltage interface.  Final specs include 9-18V power supply input, 500V maximum battery pack voltage, 2.5 uV shunt current resolution (17ma at 500A) and is Arduino IDE compatible for easy software development.  The enclosure will be waterproof and have an Amphenol connector similar to the GEVCU.  Since there is no display, for it to be useful you have to read the values with another device such as a GEVCU or any other device that can show the values on a user's device such as a smartphone or tablet.  Cost is expected around the same price as the JLD 404.

Next Session: EVTV Battery Management System "You've Got To Be Kidding" with Ed Clausen, Collin Kidder, Paulo Almeida, Celso Menaia and Jack Rickard

As anyone who has watched 5 minutes of EVTV video knows, Jack hates the "BMS" or Battery Management System.  These systems generally include a small circuit board attached to every battery that attempts to keep an even charge on each battery across the pack by reading voltage and bleeding off excess power in the higher-voltage cells as heat.  Unfortunately the failure mode for this kind of device usually results in burning down your car and whatever building it was parked in.  This is bad, because the device that's supposed to protect your battery pack actually destroys it.  Living without a BMS is tricky because you don't know the health of each cell, or at the least, each group of cells in the pack.  Jack solves this by carefully bottom-balancing each battery to within a thousandth of a volt and then the nature of LiFePO4 chemistry ensures that the batteries exactly track each other during the charging and discharging phase.  No inter-battery drift means no need to bleed off the high cells means no BMS is necessary.

So why is Jack now working on BMS systems with Paulo, Celso and Ed?  They're making Battery Monitoring Systems, not Battery Management Systems.  The PakTrakr system I had in my 914 was monitoring only, no active management.  This session will give us the first details on what Ed has been tinkering with in his shop.

The BMS will have 4 voltage inputs, giving the voltage of 4 segments of the pack, each being any size.  It will constantly sample the 4 segments and compare them, weighted properly, to see if things are getting out of sync.  The tricky thing is not acting like a parasitic load on some of the batteries and over time unbalance the pack, especially avoiding the ladder effect of multiple voltage measurements.

The heart of the system is a Sendyne SFP100 precision measurement chip, which has a very high reading resolution.  It can measure voltage, current, amperage and 4 points of temperature.  It has continuous calibration built-in to maintain the high accuracy.

The processor is the same ARM Cortex M3 as the GEVCU, and has EEPROM data storage, CAN bus, USB bus, I2C bus, digital interface to a high voltage multiplexer, 4 thermistors and an isolated power supply.  It will be housed like the GEVCU and have an Ampseal connector.  The voltage multiplexing lives on a separate circuit board with isolation on all inputs and I2C communication back to the main board.  The parasitic load is avoided by using a Bidirectional-blocking switch using two opto-isolated MOSFETs.  Each pair of MOSFETs is turned on and off in sequence.  A sampling capacitor takes about 600ms to charge up, then the ADC reads the voltage of that section of the pack.

I asked and Ed confirmed that it's theoretically possible to have one main board and multiple voltage boards, each with 4 voltage inputs due to the way he's multiplexing the voltage reading back to the Sendyne chip.  This way, people can get the amount of voltage sensing they want, from 4 points around the pack all the way down to each battery.

Ed's testing with the system involved charging with a Brusa charger and discharging through a grid-tied solar inverter.  He's seeing a lot of noise on the current sensing but that can be smoothed out in software.  Next steps include writing software for the board rather than the Sendyne test app, integration with the GEVCU, a slight redesign of the circuit board to account for a non-standard package size on the MOSFETs and creating an enclosure for the main board.

After the sessions we went back to the EVTV workshop.  The long Karmann Ghia project got a helping hand from some EVTV attendees and got it wired up and running.

The Smart car is charging and very close to being rolled off the rack and driven down the road!

And that wraps up the day!  Tomorrow we head over to the airport to get liquored up, play with high voltage and drive fast cars!

EVCCON 2014 - Day 1

Opening Keynote Session

We kicked off the official start of the 4th Annual Electric Vehicle Conversion Convention with the opening keynote speech by Jack Rickard.  This year, as last, the session part of the convention is being held at the A. C. Brase Arena in Cape Girardeau, Missouri.  I thank them for free wifi and available laptop & phone charging access!

We have 131 registered attendees and 36 electric cars this year.  The car bringers (co-hostages as Jack calls them) have special shirts with numbers on the back that match the number on their car.  We are encouraged to talk with the builders about their component and design choices.

Jack had the first time and all-time attendees stand and be recognized.  The furthest attendees were from 3 guys from New Zealand.  Coming from Thailand, I could challenge them - Google Maps says I came about 400 miles farther but it depends where in New Zealand they live...

Jack flashed back to the beginning of computer BBSs and the Internet and compared it to the growth curve of electric cars.  He's realized that 90% of the people at the show have been in the computer industry and are not necessarily "car guys".  With the proliferation of microcontrollers in modern cars, we geeks are in a good position.  We can design hardware and software that integrates well into existing cars, and we can also extract data from and send control commands to the data-enabled components we're buying and installing in our own cars.

This is a very self-selected group but about half drive their own-built electric car and about 90% are working on an EV project.  About 20 people have a store-bought electric car along with their own-built EV, such as Tesla, Ford Focus, Nissan Leaf and Coda.

Due to the exponential growth of the human population, we need to move more and more people around all the time.  These vehicles largely run on fossil fuels and there will be no end to the supply of gasoline, but the price will skyrocket as it becomes harder to find.  This is a big impetus to the rise of non-fossil-fuel vehicles.

Jack discussed the standard product adoption curve: the early adoption phase represents up to 2.5% of the market.  For new vehicles worldwide, that's about 375,000 per year.  Electric cars are selling at about 120,000 per year, so we're not even in the early adoption phase yet, so there is a lot of market space available for innovative people and companies.

Jack pointed out that as modest as we are about our knowledge about electric vehicles, people regard us as the local expert in the field, and we are key in the dissemination of the benefits of EVs and also keeping the car companies in line.

Next session: Jack Rickard on the Basics - Why to do a conversion and how to get started with the initial planning.

Jack started out by discussing the two show specials, is CALB SE Series 100 AH batteries are going at $75 each.  He has made a deal with UQM and received his first shipment of 10 UQM PowerPhase 100 motor and inverters.  These come with no factory warranty, no product support or documentation.  UQM will sell this to you for $15,000 but Jack's price is $7,000 each and he can order 20 more if needed.

Several of the speakers who initially committed to the show have dropped out, so Jack is having to step in.  Eric Kriss was initially supposed to give the basic conversion session but was unable to make it.

To do a good conversion you start out with the car of your choice and spend $25,000 to get it rolling on electrons alone.  If you try to save money, you're not going to be happy with the result.  This is only fair when you look at other hobbies such as boating.  4-line BBS systems in the '80s cost over $20,000 and you can't drive it down the street.

By the time you have purchased all of the components and designed your battery boxes, you've completed 80% of the project.  The rest is just installation and wiring.  Building an EV is very personally satisfying.

There are two major criteria: range and performance.  You've got to seriously look at your daily driving needs and design your pack size accordingly.  Battery technology does not let us go 500 miles yet.  You also have to decide if you're looking at drag racing, performance driving, highway driving, or sedate around-town driving.  You need 1 watt-hour of energy per 10 pounds of vehicle to go one mile of mixed driving.  Determining the weight of the car with this formula times your desired distance gives you the target kilowatt-hour size of your pack.  You should always put extra padding on this as you don't want to take the batteries all the way down to get the desired mileage.

DC series-wound motors are the cheapest way to get your car rolling, as they're simple motors with simple controllers.  DC systems have lower voltages (120 - 144) and very high current but a relatively low 40 - 44 lithium batteries.  AC systems are gaining market share in EV conversions due to dropping prices, more product choices and the small benefit of regenerative braking.  AC systems have much higher voltages (300 - 335) and lower amperage, but that voltage requires about 100 lithium batteries in series.  This is important in a space-constrained vehicle.  The new CAM series batteries have different form factors with quite similar capacity so you can pick the one that fits best.

Car choice comes down to weight, quality (rust-free, paint, interior, etc.) and personal style.  The more unique and sexy the car, the more attention you'll be getting as you silently cruise down the road or come out of the grocery store with your melting ice cream.

Jack talked about the genesis of EVTV.  He bought a shipment of Chinese batteries which came with no documentation, so he tested them to destruction to find out their performance characteristics.  He then tried to figure out what to do with the remaining batteries, so he asked Brian to put them into a car.  This was the first Porsche Speedster build, which went 110 miles and a top speed of 95 mph.  He was amazed that without knowing what they were doing, they made this great car - why aren't other people or car companies doing this?  About this time, Chris Paine made the Who Killed The Electric Car movie and the US government announced the financial bailout.  The rising price of gas and the result of his car gave Jack the impetus to start the videos which led to more car builds which led to an online store selling EV components.

Next session: Fundamentals of Electricity and Magnetism by Ralph Tate, Southern Illinois University

SUI offers a Bachelor's Degree in Automotive Technology, and has expanded its focus into alternative energy vehicles.  They've done two conversions so far, the second is a 1990 Miata.  The third conversion starts next month, a PT Cruiser.

Ralph teaches his students about energy, right from the basics.  He discussed energy and power, coulombs, volts and watts.  A gallon of gasoline contains 36.6 KW of power, which is about half the size of a Tesla Model S battery pack.  Gasoline engines run at about 18% efficiency but electric motors are about 85% so a lot of the power in that gasoline is thrown away as heat.

Ralph then talked about charge and force, attraction and repulsion, and conducting elements which have one electron in the valence shell.  This electron can leave and rejoin the atom without too much difficulty, leading to current flow.  An ampere (amp) is one coulomb of current per second.  Battery charge is indicated in Amp-Hours, so a 180 AH battery has 180 * 3600 = 64,800 coulombs.

Voltage is a difference in potential through a circuit.  A volt is 1 joule per coulomb.  Resistance is the opposition to current flow, measured in Ohms.  When resistance decreases, current goes up towards infinity.  This is the explanation for the real-life scenario of a short circuit shooting sparks everywhere.

Magnets!  Magnets generate lines of force from the North to the South poles.  We can create machines the exploit this force, causing rotation.  A Tesla is the unit of flux density and is equal to one Weber per meter squared.  Only some elements exhibit magnetism - they need to have non-paired electrons that spin in their orbits.  Lodestone was the first naturally magnetic material discovered.  Ferrite, Alnico and rare earths (grossly misnamed) are other classes of materials.  Neodymium has a very strong capacity to be magnetized and is hard to demagnetize, and is awesome to play with.

New magnets are made using electromagnets by running a current through a wire.  Wrapping a wire around a core gives an even stronger electromagnet.  By putting a looped wire between the N and S of a C-shaped magnet and running a current through it, the wire will turn.  We have just invented the DC motor.  There is a saturation limit of flux density, dumping more current into the motor gives no additional rotation.


Next Session: Batteries

Jack is going to do without his usual LiFePO4 battery intro talk.  They are available, predictable, stable, long-lived and almost affordable.  This session will be on long-term and temperature testing of lithium batteries by John Hardy and David Bogard.

Note all of the test results below are for Lithium Iron Phosphate (LiFePO4) chemistry batteries.  Other lithium chemistries like Lithium Cobalt Oxide (LiCoO2) and Lithium Manganese Oxide (LiMn2O4) will not behave the same way.

John has a metal shed in his back garden at home in England to do battery testing.  He uses an Arduino board to run the code for the tests, switching relays on and off to the charger and load resistor and collecting voltage and amperage values.  He stressed that any testing apparatus must draw the minimum current possible, down to the nanoamps or it will have a detrimental effect on the cells under test.

For test 1, he tested  Headway 10AH cells and had a failure at 600 cycles, but no drift in the rest of the cells.  Test 2 used shunt balancers and he destroyed his pack in less than 100 cycles.  Test 3 used CALB CA 40 series batteries and he halted the test at 2000 cycles because there was no drift and 80% of original capacity left.  He's working on test 4 right now, charging at faster rates. The preliminary data gives similar result as Test 3 but the cells lose capacity slightly faster.  More data will be forthcoming.

He also tried using dielectric grease but it actually caused the temperature at the battery terminals to raise about 5 degrees C higher than terminals with no grease, so it's not a good idea.  He found that a small number of cells are subject to self-discharge and will go out of balance with the rest of the pack, so it's important to identify these cells and replace them.  He recommends you buy a couple of spare cells for replacements.  He says to bottom balance them to within 5 millivolts and record each value.  Let them sit for three days to a week.  Most cells will bounce up slightly, and any cell that has drifted down should be discarded.

This testing validates Jack's theory that a bottom-balanced lithium ion battery pack will work beautifully for thousands of cycles if you don't use a BMS, don't over-charge them and don't over-discharge them.

Dave Bogard was up next, showing the results of his 8 AH battery life cycle testing with temperature variation.  You should go back a couple of weeks to see his video report in Jack's EVTV episode.  His basement testing lab is something to behold!  This session is a recap of his testing methodology, raw data and analysis.  He also used an Arduino, specifically the Mega 1280, a switched relay board, two power supplies and 3 fan-cooled high wattage resistors.  Be sure to use a snubber diode across the relay coil terminals to avoid a voltage spike back to the Arduino signal pin which can reboot or damage the Arduino.

He tested 6 identical Headway 8AH cells in 3 packs of two cells, at 0 degrees C (in a small bar fridge), ambient (18 degrees C) and 55 degrees C (in a toaster oven).    He initially tried to charge and discharge at 8 amps, but it was too hard on the cold battery so he changed to 4 amps.  He built a discharge / rest / charge cycle scenario against the 3 packs.

He did initial calibration with 47 test cycles and identified a bad battery which was swapped out.  He ran all batteries at ambient to 100 cycles to confirm they were behaving similarly.  Starting with test 101, he subjected them to their test temperatures.  The cold cell quickly started falling behind, ending up with about half of the charge / discharge capacity of the other two, and this is permanent damage.  The heated battery performed a little better than ambient.  This confirms manufacturer claims to avoid charging and discharging at low temperatures, but warm ambient and hot temperatures are OK.  This is good news for electric car owners in Phoenix, there is no risk of shortened capacity or lifecycle.

Next Session: Hacking Electric Vehicles for Fun and Profit

Given that I'm a computer geek and crave data and control of bits of hardware, I've been looking forward to the next two sessions.

Collin Kidder presented this session on reverse engineering CAN bus messages.  CAN bus is the standard for connecting microcontrollers in modern cars, so understanding how to connect to this bus, read data and put new commands on the bus is key to the future.  CAN actually stands for Controller Area Network, not Car Area Network as some people think.

Collin's goals for CAN bus communication includes getting more info out of the car than the manufacturer is willing to divulge, using parts from wrecks in your own car, and just because!

What data is flowing on a CAN bus?  Temperatures around the car, tire pressures, voltages, amperages, remaining range, door lock/unlock, window up/down, etc.  What gets in the way?  Lack of standardization of data messages and intentional manufacturer obfuscation.  OBD II standardized the data required for emissions testing, but not much beyond that.  J1939 is used in heavy trucks but not passenger cars.

Reverse engineering requires the understanding of how to convert from different number bases, including decimal, hex, octal and binary.  There is also the concept of Big Endian and Little Endian (Intel) ordering of the binary bits in the packet.  Some numbers are represented with a negative sign which normally takes the form of 2's Complement binary representation.  Floating point numbers, such as 3.14, take a very different form and a lot of computing power to manage, and for this reason floats are multiplied by say 10 or 100 before transmission, then divided back out at the destination.  Binary Coded Decimal is also sometimes used.  Bit shifting and bit operations such as Not, Or, And and Xor are used frequently to mask out the data you want from a larger data packet.  If none of this makes sense, take a 2nd year Computer Science class!  Been there, done that, taught that.

CAN bus is a single long cable with two wires, and is a serial bus like USB.  One wire is the + signal and the other wire is the - signal, in a differential format.  Each device just connects somewhere on the wire, in parallel with all other devices.  Both wires can float up and down in voltage but only the difference between the two wires determines if the bus has a 1 (recessive) or a 0 (dominant) on it.  Recessive and dominant is used to see if two devices are trying to talk on the bus at the same time - this is called the arbitration scheme.

CAN has a well-defined message frame format, with different fields in the frame representing different information.  Embedded inside the frame is the actual data, like the pressure of the front left tire.  The ID in the frame is key, it identifies the specific frame format for a single type of data, this way tire pressures aren't confused with battery voltages - they will have different IDs.  There are two ID types, standard and extended.  Priorities are also encoded in the ID, since ABS signals are extremely important, engine RPM is medium importance and cabin temperature is low importance.  Masks and Filters are applied as frames come across the bus, allowing you to focus on only the frames you care about, not the 3000 frames per second as you're driving down the road.

So how do we start playing with CAN?  You need a device that you can wire to the two wires, software to read and interpret the frames.  The Kvaser Leaf Light is quite good, but costs $350.  You then use the free CAN King app.  The Komodo CAN Duo runs $450 and has screw terminals for each connection to the CAN bus and a free app to drive it.  The Microchip CANBus Analyzer too is not isolated, but does a good job for $100.  The Salae Logic device is a general purpose logic analyzer that understands CAN.  BusMaster is a very powerful and free app but only supports the expensive dongles.  Vehicle Spy Pro requires its own dongle which is very expensive at $2500.  Vector CANalyzer is the gold standard but costs $5000.  Collin is writing his own, specifically designed for reverse engineering, and hasn't decided how he will release it or what it will cost.  EVTV's own GEVCU can be used too, more in the next session on GEVCU.

Now how do you reverse engineer a car?  You need to search following the characteristics of the expected data.  RPM is a large number.  Temperatures change slowly.  Triggered events just fire one frame as needed.  Just capture frames as your expected message should be coming through.  Analyze them later, looking for relevant changes.  Guessing is powerful.  Keep notes to correlate data to real events.  Watch for counter values, endian, offsets and scaling factors.  Plot data to visualize how it changes over time and compares with another data stream like commanded torque and reported torque.  Keep the wheels off the ground when testing motor controllers!

Collin then explained his steps of deduction to decode the magic byte in the Coda motor controller torque command.  It still amazes me that he was able to figure this out!

We were running about an hour late so dinner showed up just before the last session was about to start.  Everyone ran for the food, so the session will be postponed until tomorrow.

I will leave you with pictures of the vendor  area and the components they brought over that are available for purchase from the store.  I don't think some of those motors are going to be accepted as carry-on luggage!

Lonestar EV Performance is here with their design for a dedicated electric drag racing electronics and drivetrain.  The video they took of their motor with a GoPro must be seen to be believed.  That's a plasma field during the heavy acceleration.

Hi Performance Electric Vehicle Systems brought a selection of their motors and controllers.

Below are some of the EVTV components for sale.

And I'll leave you with another of Jack's upcoming projects, this beautiful wooden speedboat, with a jet ski drive system, just waiting for an electric motor and battery bank.

That's it for today, we've come back to the shop to put some more work into the Smart car.  More from the show tomorrow.