Adventure EV

Batteries

The Knowledge: Battery Tech. What’s on everyone’s mind… range.

by on Dec.05, 2009, under Batteries, EV Land Rover, The Knowledge

In an, apparently, ongoing series of articles, not directly involving my build, that I will now categorize under the title, “The Knowledge”, I present to you… Battery Tech.  Yes, it’s another boring theory post, but hey, you might learn something.

I’ll cover a bit about the types of batteries that go into your average DIY EV, address the issue of hybrids, and quickly shut down the perpetual motion and over-unity fans.

I wish I could show you pictures of my batteries, but I don’t have any yet… so for now, you’ll have to stare at random stuff I found across the interwebs.

Batteries

Range anxiety.  It’s the EV’s skeleton-in-the-closet.  Everyone seems to preoccupied with how far you can go on a charge, and that comes down to the batteries.

Battery technology is evolving quite rapidly these days.  The key to energy storage is how much energy you can cram into a given amount of weight.  Obviously, the higher the energy density the longer the range.  Here’s a breakdown of the most mainstream battery types for EV use in order of their energy densities:

Energy Densities of Different Battery Chemistries

Battery Type Energy Density (Wh/kg) Cycle Life
Lead Acid (Pb) 30-50 100-300
Nickel Cadmium (NiCd) 45-80 500-1500
Nickel Metal Hydride (NiMH) 60-120 500-1000
Lithium Polymer (LiPo) 100-130 2000-7000
Lithium Ion (LiIon) 110-160 1200
Alkaline (non-rechargable) 110 NA

It’s amazing what we can develop when we put resources behind it.  Some of it isn’t as new as you might think.  Lithium battery chemistries have been around for a few decades, now.  Lithium Ion first saw commercial use in the early 90s.  I always thought they were a relatively new development.  And Lead has been around since the middle of the 1800s.  Battery tech isn’t new, it’s older than the internal combustion car.  EVs aren’t just the future, they were the past.

Lead Acid, the very same battery that powers the 12v electronics in your conventional car, is the cheapest way to provide energy storage for an EV, but as you can see from the chart it’s also the least energy dense.  Lead is one of the heaviest metals on the periodic table, hence it makes for some of the heaviest batteries.  Typical Lead EVs have ranges between 10 and 40 miles per charge.

Lead Acid Batteries

While “Lead Sleds” may initially be inexpensive to get into, Lead has some serious disadvantages over the long haul.  Their limited cycle life means they need to be replaced every couple of years.  They also don’t like being drained of all their energy.  Sapping more than about 50% of the storage capacity of a Lead battery severely shortens its cycle life.  So, not only do you get the least amount of energy storage, with Lead, but you can really only use about half of it… and they don’t last as long.  But they’re cheap.  A conventional set of Lead batteries for an EV can go for $1000-2000.  If you’re on a tight budget and your range needs aren’t extravagent, Lead can make sense.

The middle technologies, NiCd and NiMH really don’t get much play in the homebuilt EV world.  NiCd has about the same storage capacity as Lead but benefits from a much greater cycle life and durability.  The problem is, it’s ten times more expensive.  So it really doen’t make much sense for the home EV builder.

Nickel Cadmium Battery Pack

NiMH is also expensive, but it’s the battery of choice for today’s production hybrid car producers.  The technology has been proven to be quite safe and reliable, if not the highest performing.  This has probably more to do with the way the OEMs utilize the cells.  The Toyota Prius uses a NiMH battery pack, but it’s rumoured the electronics only allow the pack to be charged to about 50% capacity and then only allowed to discharge about 7% before being charged back up to 50% again.  It makes for an extremely long lasting battery since it’s never pushed, but that’s carrying around an awful lot of unused battery.

Nickel Metal Hydride Battery Pack

Then we come to the high rollers of the battery world, the Lithium chemistries.  Lithium Ion has the highest energy density of all the mainstream commercial battery chemistries.  Lithium Cobalt (LiCoO2), a form of LiIon technology is the same stuff that powers your cell phone, laptop, or even the Tesla Roadster (powered with 6831 AA-sized cells) .  It’s expensive stuff, but since Lithium is the lightest metal on the periodic table it makes for the lightest batteries.

The biggest problem with a battery like Lithium Cobalt, apart from cost, is safety.  These are the same cells that were seen catching fire in laptops.  If something goes wrong with one of these, they go into a thermal-runaway chemical reaction, and poof… there goes whatever you were powering.  They’re getting safer every day, but the explosive potential is always there.

I’m using Lithium cells in my conversion, but I’m using a Lithium Polymer cell, a variant of the Lithium Ion technology.  Lithium Polymers were the most recently developed type of cells, first seeing use in the early part of the decade.  The most popular format for EV converters has become the Lithium Iron Phophate cell (LiFePO4).  In recent years they’ve really become a real game changer.

Thundersky LiFePO4 Battery CellLiFePO4 cells aren’t as energy dense as a Lithium Cobalt battery, but they also don’t do the whole blow-up-if-there’s-trouble thing.  They’re also cheaper to manufacture and have very long cycle lives.  While Lead gives up the ghost after only 300 charge cycles, LiFePO4 cells might see upwards of 3000 cycles while using 80% of the capacity of the cell!  If you drove 50 miles per charge that’s 150,000 miles.

LiFePO4 cells being studied at the US Department of EnergyLabratories in New Mexico have hit 7000 cycles and are still going.  This kind of cycle life surpasses even traditional Lithium Ion technology (~1200 cycles), making the Lithium Polymer cell one of the most economical chemistries over the long run.

LiFePO4 is also completely non-toxic and recyclable.  Even at the end of their useful lives in EVs, the cells can be reapportioned for use in solar power installations as storage, since weight isn’t an issue in this capacity.

Faster, lighter, farther, longer, safer…  Sounds too good to be true.  Well it could be but for the hard initial pill to swallow.  The price of admission to the LiFePO4 party isn’t exactly cheap.  A typical EV battery pack that would provide between 50 and 150 miles of range could cost between $6000 and $20,000.  When considered over the life of the pack, though, LiFePO4 becomes about as economical as Lead.  It’s just a very large initial investment.  While Lead will have to be replaced every couple of years, the LiFePO4 pack should last over ten… and you get the added benefits of better range, lighter weight, and higher performance.

As automakers scramble to offer pure EV cars to the public, many are planning on using LiFePO4 technology.  This will surely drive the cost done for the future.

And the future is bright.  New chemistries continue to crop up all the time.  Companies are trying to develop ultra-capacitors, lightweight electronic storage devices that are capable of storing energy and releasing it very quickly.  While capacitors traditionally don’t have anywhere near the storage density of even the lowliest battery, a company, EEStor, is claiming that their ultra-capacitor design will be capable of storing close to 700 Wh/kg, some six times greater density than Lithium Ion, and that the technology will cost $40 per kWh, compared with LiFePO4’s $350 per kWh.  So far it’s just vapourware.

Ultracapacitors

Researchers at the University of Dayton Research Institute are developing Lithium-Air cells that could be capable of storing 1000 Wh per kg, or ten times the density of today’s Lithium Polymer cells.  Imagine that, my 33 kWh, 780 lb battery pack reduced to the weight of just 73 pounds!

That’s the future… and it may not be that far away.  That kind of technology would give my Land Rover a 900 mile range.  A more efficient vehicle would be able to drive across the country on a single charge with a battery the weight of just one conventional Lead-Acid car battery.  It’ll be a trick trying to find enough energy to fill the things, but that’s a problem for another day…

Hybrids

On the topic of range, a couple of people have asked me whether you can use a small generator to power the EV, and the answer is yes.  What you will have built is a “Series Hybrid”, one in which the engine generates electricity to fill the batteries which power the motor to move the car.  This is different from the parallel hybrids, such as the Toyota Prius and Honda Insight, which use the engine primarily to motivate the car while the motor acts as a booster.

Honda Insight Hybrid

The upcoming Chevy Volt is an example of a series hybrid.  The car is always powered by the electric motor and battery system.  When the batteries run out of the juice, the ICE starts up and charges them.  In this configuration, the car has about a 40 miles range on pure electric before the engine kicks in.  The ICE is never mechanically connected to the wheels.

The problem with the current crop of hybrids is that since they use the ICE for primary motivation the engine has to be large enough to do all the cruising and accelerating, so it’s heavy.  You end up carrying a large engine and a large motor around, both doing their jobs more efficiently as a team, but still leaving a lot on the table.  Think about the last time you utilized the full potential of your ICE, and for how long.

The same thing could be said for an electric motor that has more than “enough” power, but the motor is so darned efficient, it’s less of an issue.  Besides, electric motors work differently in their ability to generate power compared to an ICE.  I’ll explain more in a bit.

An ideal series hybrid uses an engine only big enough to provide an amount of power slightly greater than the car’s demand at cruising speeds on the highway.

2010 Fisker Karma Series Hybrid

Upcoming Fisker Karma, a series hybrid, has twin 201hp electric motors for a 0-60 time of less than six seconds. Batteries are charged with a turbocharged 2.0L GM Ecotec Direct Injection engine. Only $87,000... gulp.

Acceleration requires a lot of power.  The only reason to buy a 200hp vehicle (about what a Camry Hybrid has) is for acceleration, because most vehicles only use a fraction of their total power to sustain highway speeds.  Even my brick of a truck only requires a projected 32 hp to maintain 60mph (at 7000 ft ASL).  That’s the power needed to overcome the aerodynamic drag, rolling resistance of the tires, and drivetrain friction.  But a 32 hp engine would mean extremely slow acceleration.

Here’s where the series hybrid concept comes in.  The electric motor provides a large amount of power for acceleration, while the ICE charges the battery at a rate only needed to sustain a moderate constant speed.  For example, 200 hp out of the electric motor for acceleration, but only 30 hp out of the ICE for cruising.   That way, the ICE can spin at its most efficient, constant speed, sized just large enough to provide 90% of the driving needs, and the electric motor and battery system can take care of the muscle.  Since our driving usually only involves short bursts of acceleration, the battery system will always be replenished by the relatively small ICE.

Let’s take the Chevy Volt, again, as an example.  It has a 160 hp electric motor, but only a 71 hp ICE.  If it were a conventional car, trust me, the 71 hp would be marginal for today’s perceived needs.  At around 3500 lbs it would take around 18 seconds to accelerate from 0-60 (funny, my Land Rover had a very similar power to weight ratio and far worse aerodynamics…)

But with 160 hp on tap from the electric motor, the Volt could do the same run in about 9 seconds.  Much more reasonable performance.  Then when it’s on the highway using a whopping 30 hp to maintain 70 mph, the 71 hp ICE would have more than enough power to sustain the speed and give the batteries a little charge.

2011 Chevy Volt Hybrid Layout

I’ll get back to the issue of how electric motors produce power, now.  One key difference between an ICE and electric motor is that an ICE can produce its peak amount of power continuously.  An electric motor is typically rated for its ability to provide power on a continuous basis, but beyond that it may have the ability to produce three, or more, times its rated power for brief spurts.  That means that my Kostov, rated at 52 hp, can make 52 hp all day, but it can also do 160+ hp for shorter periods of time.  Perfect for acceleration,and perfect for the way we drive.  Unlike the ICE, the electric motor can be smaller because its power can be overrated for a bit.  It’s like having a that 71 hp-sized ICE that can do 160 hp for acceleration in a pinch.

So, yes, it’s possible to use a small engine or generator teamed up with the EV power system.  Another term for this setup is a “Range-Extended Electric Vehicle”.  Because of the public’s increasing interest in hybrids, and automakers’ need to build more efficient vehicles in order to satisfy government efficiency mandates, companies are starting to develop range-extender engines, small engines designed to power generators to charge batteries.

Lotus, one of my favourite auto and engineering companies, has developed a little 1.2 liter, 3 cylinder engine that can produce about 45 hp.  It has an integrated generator and the whole setup weighs a paltry 123 pounds.  Perfect for a lightweight, series hybrid.

Lotus Range Extender

But implementing this idea isn’t so easy, so it really isn’t done much in the DIY world.  People have towed little generator trailers for extended range, but integrating an engine system on-board… that’s tricky.  For one, the electronics required to manage the whole affair are over most peoples’ heads.  And fitting an engine in with the already crammed electronics needs of the EV is another hurdle.  Remember, with most EV conversions, a lot of space is used by the batteries.  While I’m lucky enough to be able to carry all of my cells outside of the passenger compartment, a quick look at BMW’s EV Mini proves the point… the entire rear seat is consumed by batteries.

You could use less batteries (the Volt uses about half the batteries I’m using) to have more room and less EV range, but you’re really not building an EV anymore… and efficiency will lie somewhere between the conventional and EV version of the vehicle, probably more towards the conventional side.

This is why it all comes down to your particularly needs.  If 90% of your driving can be accomplished with the range of a pure EV then a pure EV makes sense.  If half of your driving involves greater distances, then an EV may not be the right choice.

At the end of the day from a DIY standpoint, it’s just not as practical… and certainly not as efficient.  But that won’t stop me dreaming about one day building my turbine-hybrid powered supercar…

I have heard instances of people using little generators to give their packs an emergency charge just to get the last few miles to home in the event of range miscalculation, shall we say.

Perpetual Motion and Over-unity

This one is easy to get, but difficult to fully understand.  If you take it on rote that the laws of physics actually apply to our reality then you will have no problems.

1920-10-Popular-Science-Norman-Rockwell-cover-Perpetual-Motion-400-Digimarc

Someone asked me once, why not stick a wind-turbine on the car to generate electricity to fill the batteries while moving?

The brief answer is that for it to work, you’d be defying the laws of physics.  People forget that a wind-turbine creates drag.  It’s what happens whenever any object obstructs a flow of air.  In the case of a wind turbine, the flow of air spins the blades which generates electricity, but the amount of energy produced is far smaller than the amount of energy that goes into moving the blades through the air in the first place, because wind turbines aren’t very efficient.  Only 30%, or less, of the available energy used to spin the turbine blades gets converted to electricity.  Stick one on a car, and you’ve successfully created an airbrake.

Same thing with putting a generator (or alternator) onto the driveshaft to recapture energy while driving.  There’s no doubt that you will recapture some energy, but you’ll be recapturing less of the energy you put into moving the vehicle, to drive the generator, in the first place.  Much less.

This is true of every technology.  There is nothing out there that will produce more energy than is put into it.  Some things get close… AC electric motors by themselves for example, are theoretically capable of converting 98% of the potential energy feeding them to kinetic energy.  But “close” is still a literally, impossibly far cry for “more than 100%”.

Wind-Turbine-Car-and-Truck

Adding things like wind-turbines or alternators to capture energy just increases the overall energy consumption via drag.

That’s not to say that these device can’t be useful… well, maybe not the wind-turbine on a car.   Some people have used modified alternators to slow the vehicle when braking.  Instead of the energy of the moving car being converted to useless heat by the friction of the brakes when stopping, the energy is recaptured and stored in the batteries for later use.  Certain motors have this “regen” capability, as well.  The key is that, the devices are only used when energy would normally be bled off as something useless, like heat.  And it still ain’t over 100%…

I’ve seen some ingenious devices out there, but all of them will eventually slow and stop when not supplied with energy.

And if you’re still hanging on at this point… congratulations!  And goodnight.

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Battery Box Progress

by on Nov.18, 2009, under Batteries, Battery Boxes, EV Land Rover, Fabrication

I certainly expected to learn a lot embarking on this endeavor, and I have.  But something I didn’t really need to learn was that cutting 1.5″ x 15.” x 1/8″ angle iron with a 12″ mitre saw and an abrasive cut-off wheel… takes FOREVER!!!

So far I’ve cut pieces for three of the four battery boxes… 12 pieces for each box, two cuts for each piece, for 72 cuts altogether.  45 degree angles are the worst.  It’s like cutting thicker material.  The wheel just spins round and round… and round… and round before it cuts through.  I thought it would be like butter,  but it’s more like cutting through a can with a nail file, metal dust everywhere.

Cutting Angle Iron

And the abrasive cut-off wheel doesn’t cut cleanly at all.  Every time I complete a cut I have to de-burr, bevel, and smooth the edge with a 4″ angle grinder.  It just gets tedious.  Took a couple of days.  Word of advice, don’t do this without ear defenders and other normal safety gear.  You’ll go mental without the ear protection… and deaf.

I’ve heard of chop saws that use carbide-tipped metal blades that do cut metal like butter… and cleanly.  If I was doing it for a living I’d purchase one in a second, but they’re ex-pens-ive.  Another word of advice, get one of those!

But then it was on to welding, and for some reason welding is far more enjoyable.  I dunno, there’s something about melting two pieces together by brute force… and a lot of electricity… and sparks.

Welding

So after the past couple of days, the two frames below are the result of the fruits of my labor.  And what do you know, they actually kinda fit.  Tomorrow I complete the rear box frame… the big one.  That shouldn’t take long.  The welding is relatively quick and painless.  But I’ve run out of shielding gas… wish me luck trying to find some.

I purchased some thin gauge aluminum sheet which will act as the box walls.  That will be sealed in and riveted, not welded, and I can cut that stuff with electric metal shears.  Hopefully this time it will cut like butter.

Side Box Frames

I also pick up my motor spacer tomorrow…  hopefully.  It’s Taos.  Every time I call to see if it’s done it hasn’t been started.  Life moves at a different pace out here.  Luckily I’ve been preoccupied with the fabrication work, and I haven’t been pushing the machinist.

I dropped my flywheel off earlier in the week to have the starter teeth and a bit of the back side shaved off.  Maybe I can cut its weight by a third.  It’s a heavy bugger, so any weight savings would be nice.  It was a spur of the moment decision, so I failed to weigh it prior.  Oh well… heavy.  That’s how much it weighed.

Maybe I’ll never see my parts again…

For those looking for sources for parts and pieces:

1.5″ x 1.5″ x 1/8″ Hot Rolled Steel Angle – 80 ft @ $87.75 ($1.10 linear foot)

60 sq/ft .040″ 5052 Aluminum Sheet – $140.19 ($2.34 sq/ft)

Purchased at Metal Supermarkets in Albuquerque, NM.  You might find an outlet near you, or you can order online.

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Weight Gain…

by on Nov.17, 2009, under Batteries, Battery Boxes, Design, EV Land Rover

Well, you can’t get something for nothing.  For now, the Rover remains on a strict diet.  But the plan for the not-so-distant-future involves bulking up a bit.  Actually, quite a bit.

I’ve got the motor.  I’ve got the motor controller.  You’ve seen those.  The last major bit of the equation is the batteries, and you havent’ seen those yet.  This is largely because they’re on their way to the USA by way of a large container ship from China.  At least, I hope they are.

While the engine in an ICE car is the heaviest, most expensive part of the drivetrain system, with an EV this task falls to the batteries.  In my case, about 790lbs worth of these:

Thundersky 160Ah LiFePO4 Cell

That is a 3.2v 160Ah LiFePO4 cell from Thundersky.  It’s about one quarter the size of a conventional, large lead acid battery, the kind you’d find in a pickup truck.  My conversion is using 64 of these battery cells, for a total nominal voltage of about 205v (240v peak charge).

I’ll try and give some perspective on the battery system.

Battery capacity is usually given in units of kilowatts (kW).  That’s 1000 watts.  If you were to burn ten 100 watt lightbulbs for one hour,  or one 100 watt lightbulb for 10 hours, you’d consume 1kW of energy.  If you had a battery that contained 1kW of energy… well you get the picture.  An average home in the US consumes about 30 kW of electricity a day.

One gallon of petrol (I use the word petrol because it’s petroleum, a liquid, while gas is… gaseous) contains about 36 kW of energy.  My battery system will contain about 33 kW of energy (3.2v x 160Ah x 64 cells = 32,768 watts).  Not even the equivalent of one gallon of petrol.  But, I’ve projected my EV’s range at between 50 and 75 miles utilizing a conservative 80% of the battery pack’s storage capacity, for cell longevity.  The low end of the range is calculated with the vehicle travelling at a constant 65 mph, while 75 miles is with the vehicle travelling 40 mph.

The Land Rover is horrendously, aerodynamically inefficient (there’s a tire on the bonnet… which is what I call the hood because, it’s British… the Rover, I mean), which explains the differences in range at the different speeds.  At speeds above 40mph most of the power used to move a vehicle goes into fighting the air, since drag goes up with the square of speed.  Every doubling of speed requires four times the power to counteract the atmospheric drag.  As a comparison, a Toyota Camry has a total drag index of 7.57, while my Land Rover comes in more like 18.  A Prius is a low 6.24, while GM’s electric car from the past, the EV1 was a very slick 3.95.

Rover Sunset

Since it takes more energy to push a boxy truck through the air, the Land Rover is at a disadvantage, but for speeds around 40mph drag becomes less of an issue.  And for its intended purpose, as a vehicle designed for local trips into town, 40mph is perfect… as is the range capability.  In fact, here in the Rockies the atmosphere is up to 20% thinner than at sea level, so that’s 20% less air to push.  With an ICE car, that means a corresponding loss of 20% power (20% less oxygen in which to mix and burn with petrol), but the electric motor doesn’t care.  Chalk up a bonus for EV power at altitude!

Imagine the numbers, though.  I’ll have less energy than a gallon of petrol onboard, and while counting on using only 80% of that, I’ll be able to travel 75 miles.  Astute math students will notice that’s more than 75 mpg (it’s actually more like 90 mpg)… in a 38 year old Land Rover!  That’s about five times more efficient than the 15-18 mpg the truck delivered with its internal combustion engine.

Throw the electric drivetrain in something lighter, smaller, more aerodynamic (pick any modern sedan or wagon), and you might see 125 miles of range, or 130 mpg.

In an ICE most of the energy extracted from the petrol is wasted as heat.  Only 20% makes its way into motion.  With an electric motor very little energy is wasted as heat meaning almost all of the power goes into turning the motor shaft.  Some are capable of being 98% efficient at turning electrical potential energy into kinetic energy.

But back to the batteries for second.  I mentioned in a previous post that I had managed to extract about 700 lbs of ICE related equipment that I wouldn’t need.  Well, with the batteries alone, it’s all coming back… and then some.  But the Rover will be faster, stronger than before.  So it’s more like 700+ pounds of muscle.  Beefcake!  Beefcaaaake!!!

Cartman from TV's South Park

Where to put 790 pounds of batteries?  The Land Rover, having a truck-based, ladder chassis, means that there’s a lot of space under the vehicle around the frame in which to hide stuff.  After taking lots of measurements and using Google’s free Sketchup program, I was able to find a very close-to-scale model of my Land Rover online.  This allowed me to mock-up component placement to give me an idea what I could fit where.  It’s been tremendously helpful, and Sketchup is pretty easy to use.

RoverEVConversion_HV

You can click on the same image in the gallery below to see a larger version.  The yellow boxes are the battery cells, and you can also see a rudimentary layout of the electrical runs.

I completed this mock-up several weeks before heading to Taos to work on the Rover… and it has proven to be very accurate.  There will be one modification to the rear cells, however.  The Sketchup model’s rear differential pumpkin isn’t fully realized.  On the real thing, it interferes with the rear battery box as laid out, so I’ll have to turn some cells sideways and figure out a location for two orphaned cells, to make room back there.  They’ll probably go up front somewhere.

The side fuel tank locations are being used as they exist on the truck.  I modified my truck for a rear fuel tank a long time ago, so there’s a position there.  The front is now bereft of engine and cooling radiator, so there’s plenty of space up there.

There are a couple of nice side-benefits to this setup.  For one, the cells sit low in the chassis which lowers the vehicle’s center of gravity.  This is a benefit to safety and capability.  Secondly, much more weight transitions from the front to the rear compared to the ICE layout.  This should improve weight distribution from the ICE’s 60/40 front rear split.  In fact, there will be about 300 lbs of batteries in the rear, 160lbs on either side, and 240lbs in the front.

Wait!  Said astute math students will note that, that is more than 790 pounds.  Indeed, all those battery cells must be contained within four separate battery boxes, which I will be constructing out of 1.5″ x 1.5″ x 1/8″ steel angle iron and some thin sheets of aluminum.

But before I can bust the metal out, I need to know for sure that the battery boxes will fit the truck.  Pre-visualizing the layout is great for a start, but as with the differential pumpkin, what you see in the virtual world is not always what you get.

So I spent a cold, snowy, windy Sunday building battery boxes out of cardboard… and then crawling around under the truck  discovering what would really fit.  This is when I was alerted to the differential clearance issue.

Battery Box Mock Up

Now that I have the actual dimensions I need, I can get started on building the real boxes.  It’s been over a decade since I last picked up a MIG gun, but it’s like riding a bike!  It comes back quickly.  This was my first weld on some practice pieces.  They can only get better.

First Weld

For those curious, I’m using a 110v Lincoln Electric Weldpak 100 MIG welder that I picked up at Home Depot in the mid-90s for about $300.  It’s got a gas conversion kit, and I’m running a 75%/25% Argon/CO2 mix.  I’m amazed that 12 years later there’s still a gas in the cylinder!  I’m probably running near the limits of what this particular model can handle, though it shouldn’t be a problem.

MIG welders make it really easy for the lay-person to weld.  I originally purchased the unit to make sheet-metal repairs to the Land Rover’s rusted steel bulkhead.  I self-taught myself, so just about anyone with any creative aptitude and desire should be able to pick it up.  And obviously, it’s been a handy skill to have.

Speaking of which, how did I do the performance projections on my Land Rover?  I used a performance analysis spreadsheet that I found at Brian Hughes’ MR2 EV Conversion site.  We’ll see how the real thing turns out.

The internet, in general, has been where I’ve learned most of what I think I know now.  Only finishing this project will answer whether I actually know anything useful, but for those wanting to learn more about EVs, conversion, batteries, motors, all this stuff… there are a couple of great web forums with people far more experienced than me giving their two cents.  One site in particular, the DIY Electric Car forums, has been where I spend most of my time learning.  Imagine that, an entire site dedicated to homebuilt EVs!

Another interesting resource to peruse is the EVAlbum, a web site dedicated to people’s DIY conversions.  Everything and anything has been converted, and you can find out what goodies were used and how well the resulting EV performs.  Fun for finding really weird stuff.

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