Wednesday, August 29, 2012

The Hybrid Farce

I really don't think they should be allowed to call what we know as hybrids, "hybrids". They do not actually use anything other than gasoline to make themselves go. Sure, battery and electric wizardry makes them much more efficient by harnessing kinetic energy when slowing down and turning it into forward motion (instead of brake dust and heat) when the time is right, but that's not my point. Every bit of energy that provides forward motion still comes from gasoline.

And this leads to what I would call a true hybrid - the PHEV - the plug-in hybrid electric vehicle.

What is a PHEV? Well, it's basically a normal "hybrid" vehicle but with a much larger battery pack that can be charged by a household electrical outlet. This allows it to be driven for a while on nothing but electricity, paid for by your Hydro bill, until it runs out and the ICE has to fire up and take over.
That is an actual picture of the Prius Plug-In Hybrid, folks.

Many hardcore EV advocates scoff at the PHEV idea, saying that it's not enough. But I think PHEVs are the answer right now, and if I had enough money I would buy one immediately.

Most advocates are promising a new battery technology that is right around the corner that is going to propel the BEV (Battery Electric Vehicle) into mainstream. But I would argue that this technology isn't going to come any time soon - at least not in our lifetime. Take our current high-tech batteries as an example - the various types of lithium batteries. They are good, but at the same time they are only four to five times as dense as lead acid batteries, energy per pound. So in one hundred years of batteries, they have only improved by a magnitude of four to five.

That's where PHEVs are brilliant. They provide BEV-like efficiency for 90% of situations that most people use cars for, and once the modern battery technology shortfall kicks in (and the battery is flat), the ICE takes over, so there's nothing to worry about. Take the Prius as an example. It has an estimated 22 km of EV range. That's not much, but when you consider that 90% of trips are less than 22 km, it sort of makes sense. Even if your trip is 40 km, you are still driving for pennies for the first half. And if you need to go on a road trip, you don't have to think twice about it.

There is going to be a whole bunch of new PHEVs coming soon. Ford has a bunch coming, both in the Fusion and the new C-Max Hybrid Energi. It seems that Ford's aim right now is to beat Toyota at "everything Prius," which is ironic considering Toyota supplied hybrid technology to Ford up until recently.

Here is the soon to be released Ford C-Max with higher EV efficiency and longer EV range ("more than 20 miles") than the Prius Plug-In:
Wait a minute...THAT looks like it could be a PHEV replacement of a certain Toyota Matrix I know of. Hmmm......

Holiday Thinking

One thing to report: I did in fact receive my 1" keyed hub in the mail and I did in fact weld it to my splined clutch centre. Did I weld it straight? I sure hope so. I fitted my new 1" keyed hub to the motor shaft and much to my dismay, in very "Princess Auto-esque" fashion it fit quite loosely to the motor shaft. No precision here, folks. So when I tighten the set screw, it pulls the coupler to one side of the shaft so that it wobbles a tiny bit (0.010"-0.020" or so) when the motor is spinning. Hmm...that's not good.

So here I sit on an 11 day holiday at our Hacienda in Osoyoos, trying to think of what I should do. And here's what I have come up with: I will discard the set screw on the motor shaft portion of the coupler to allow the coupler to float on the motor shaft. The clutch splines of the coupler fit quite snug on the transmission input shaft and there is no radial movement of the coupler there, so the coupler's radial position will be located by the transmission input shaft only and the motor shaft will float in the opposite end (the loose end) of the coupler.

There will not be an issue with the coupler moving fore and aft because I welded a washer between the 1" keyed portion and clutch spline portion inside the coupler to prevent it from moving.

The question is, should I put grease between the coupler and motor shaft to prevent the key from wearing out as the coupler moves around on it? I don't know. It will definitely work, but longevity has now become a giant variable.

Thursday, August 23, 2012

The Part I Am Waiting For

...is this (which will go on the motor shaft):
...that I will weld to this (to drive the transmission input shaft):
...which I cut from the center of this:
The Canada Post tracking number search says that it will arrive today.

Wednesday, August 22, 2012

Question: Why Electric - Part II [The Error In My Math]

So today in the local paper I saw a dealership ad for the Chevy Volt starting at $33K (including the Canadian Government $5000 rebate and manufacturer's rebates). That's $10K less than what I thought, and that sort of changes the tune from what I wrote a few days ago, hey?

Strictly numbers speaking, this means that in the Cruze vs. Volt cost per kilometer average it would only take 174,029 km for the price premium of the Volt to offset its fuel savings. That's much better!

This got me thinking even more. Who buys vehicles based on price per kilometer anyway? I mean, to a point we do, but only when looking at a few similar vehicles that we desire like, say, pickup trucks, which 75% of people who own don't actually need. People (including myself) buy vehicles that put smiles on our faces, and that usually involves a price premium.

If this were not the case, every person who needed a commuter car would buy a sub-compact. Everyone who needed haul stuff once in a while would buy a sub-compact with a hitch and a matching utility trailer to pull behind. But, there would be much fewer smiles on faces.
Back to the Chevy Volt. I dare say that a Chevy Volt would put a smile on my face, and therefore would be worth a price premium. I would probably purchase a Volt if it wasn't a first attempt by GM (okay, maybe if it wasn't built by GM at all) and if it had more than two seats in the back and if it was a wagon like our Toyota Matrix. I guess what I am really saying is that if a car company decides to release an electric Toyota Matrix clone with a range extender gasoline engine, I will definitely be tempted.

What's the chances of that happening?

Tuesday, August 21, 2012

Inspiration

Every project needs inspiration of some sort.

There are two noteworthy EV conversions that I have been motivated by. Both of them are ultra-low budget conversions, and both of them were converted by guys who were not extremely mechanically savvy when they set out. I will have to admit - this whole EV conversion thing is a bit daunting. Here I am, an actual mechanic by trade, yet I foresee the possibility that my electric car may not come to fruition. It may not work well enough to get me to work. I might lose interest. But these guys put their heads down and went for it, with magnificent results.

The first one is the grandaddy of all budget EV conversions: Darin and Ivan's ForkenSwift. Using used forklift parts and used golf cart batteries, these guys built an electric runabout out of a Suzuki Swift for under $1000. The build thread on Ecomodder.com is a good read, and can be found HERE.

The second one is Ben Nelson's Electro-Metro. Not quite as cheap as the first one, but lots of testing with different voltages, controllers, chargers, etc. Ben even added a propane powered generator later on, making it a series-hybrid. The build thread on Ecomodder.com can be found HERE. Ben's website also covers his motorcycle conversion (HERE), which I would also love to attempt one day.

Anyway, back to The Electric Booger. Nothing new in terms of progress, but here is a picture of the current state of my garage:
It's crazy but it's true.

Sunday, August 19, 2012

Question: Why Electric?

Good question.

It seems that most electric car proponents are what we generally call "tree huggers." I can tell you that I certainly do not fall into that category. I do agree that we need to take care of God's green earth as best as we can. However, I do not necessarily agree that this means reducing our carbon dioxide production as much as possible for the purpose of "saving our planet."

What it boils down to is the viability of each and every energy option. Currently, gasoline is the most economical way to power a car when the convenience that it provides is taken into account. Our current price of fuel is still quite cheap. But we all know that the price of fuel will continue to escalate, eventually reaching a point that prohibits its consumption altogether, leading to more viable energy options.

Take current vehicle options as an example: the Chevy Volt (starting at $43K) versus the Chevy Cruze ($20K, similarly equipped). If you drive the Volt solely on electricity from your home charger, it will cost you $1.79 worth of electricity per 100km, using EPA ratings and an electricity price of $0.08/kwh. The Cruze with cost you $9.26 worth of gasoline per 100km, using the combined EPA rating and a gasoline price of $1.25/L. Using simple math, it will take 307,898 km of driving the Volt (on electricity only, never using the range extending gasoline engine) to offset its $23K price premium. And I would argue that by then, the Volt's lithium battery pack will have packed it in a long time ago.

Another example: the Nissan Leaf (starting at $38K) versus the Nissan Sentra ($23K, similarly equipped). The Leaf will cost you $1.69 worth of electricity per 100 km and the Sentra will cost you $9.79 worth of gasoline per 100km. That difference will take 185,185 km to offset the price premium. That's not so bad, but at that point I wonder how much longer the Leaf's battery pack will last. Only time will tell.

Since the mid-1990's, we started to hear about hydrogen, and how it is the next "real" answer to the car problem. What most people fail to see is how much energy is used by producing the hydrogen in the first place. Commercially produced hydrogen is made from natural gas, and the process produces ridiculous amounts of carbon dioxide. Sure, a hydrogen car itself does not pollute, but the making of hydrogen pollutes like crazy. You have to view the whole thing in terms of "well to wheels" instead of just "gas pump to wheels."

Electricity isn't perfect either. Most power in North America is produced by coal and natural gas, so producing electricity pollutes as well. However, thanks to a huge flaw in the internal combustion engine, it is still a more viable option (pollution wise) to use electricity for power.

What flaw? The gasoline engine's flaw is efficiency, or lack thereof. The average gasoline engine in a car is approximately 30% efficient, at best. That means of all the available energy in a litre of gasoline, only 30% is turned into useable power. The rest goes out the tail pipe and radiator as wasted heat, and that is under ideal conditions. By comparison, an electric car can be over 75% efficient in turning electricity into useable power.

Let's pull out a chart, shall we? Keep in mind that I stole this out of a publication by Tesla Motors, a current producer of electric cars.
When keeping the "well to wheels" idea in the picture, you can see that the worst polluter is the natural gas car, followed by the hydrogen fuel cell car, the diesel car, the gasoline car, the gasoline electric hybrid car and finally the electric car. When we consider that most electricity consumed here in Western Canada is hydroelectric, the electric advantage is substantially larger!

Now, this chart is a comparison of greenhouse gas emissions, which I am not too interested in. While I can admit that human produced carbon dioxide may be accelerating global warming, I see the whole global warming principle as a politically and financially tainted movement that tossed science out the window a long time ago.

What I am interested in is the viability of each type of energy. As we saw in our car comparisons above, the cheapest form of energy is not yet a viable option in a vehicle. But a second cheap option is natural gas fuelled vehicles. Since natural gas is not tied to the price of crude oil and since it is available in abundance, it is a cheap energy source. Natural gas conversions are available for almost any vehicle. One could even set up a natural gas fuelling station in their own garage if they wanted to. But..well...that's still boring. I want to build something different and exciting, not something that drives and sounds the same as everything else on the road.

And while mass produced electric cars are not yet financially viable, I think EV conversions are - especially my electric car (and especially if it actually works!) because of my unlimited source of free battery cores, keeping in mind that batteries are always a consumable item because even the best ones do not last forever.

But that's still not why I am building an electric car. The true reason is that I am doing it for fun and nothing more. Apparently there is a phenomenon known only among EVers called the "EV grin." It is the ridiculous smile that you can't wipe off your face the very first time you drive your newly converted electric car, and for years I have wanted to experience it!

That's all for now.

Saturday, August 18, 2012

Adaptation 1

Recently, I have been working on adapting the electric motor to the MX-3's manual transmission. I have decided to go without a clutch, direct driving the transmission input shaft with a simple coupler. Shifting gears may be slightly more difficult without a clutch, but since the electric motor will have much less rotational inertia than the engine it is replacing, it will be doable with a bit of practice.

I started by adding some strength to the mounting configuration of the electric motor. You can see in the picture that there are only three tiny 5/16" threaded holes at the edge of the motor face for mounting stuff to this side of the motor:
Not really strong enough, in my opinion. So I carefully measured and drilled and tapped three more threaded holes, complete with studs, all in 10 X 1.5mm - much bigger and much stronger. Overkill is good, right?
Next I drilled a bunch of holes in my 1/2" aluminum adapter plate and mounted it to the motor:
This is where I am stuck at the moment. I am waiting for a 1" keyed hub to arrive in the mail so I can weld it to the splined centre that I cut out of the clutch friction disk to make a very simple coupler between the motor and the input shaft of the transmission. Princess Auto had every imaginable size except for the size I need (of course), so I had to order it off their website. Speaking of coupler, I hacked the pilot bearing spigot off the end of the transmission input shaft too.

Before:
And after:
It took all of one minute, thanks to my die grinder and cutoff wheel. I'd better watch it - I'm turning into a machinist!

De-ICE-ing

ICE = Internal Combustion Engine.
De-ICE-ing means...well, that's not hard to figure out. All I can say is it's a common saying around EVists. EVers. EV nerds?

I will let the pictures do the talking.
I wonder what health and safety would think of this one? Don't worry - I didn't go underneath.
Everything that needs to be out, is. The Electric Booger officially will never burn a drop of gasoline again. Hopefully soon it will be running on water. (Hydroelectric power). Dumb joke, sorry.

The Motor and Controller

Probably the two thing that everyone asks about the most.

Typically in EV conversions, a series wound direct current (DC) motor is used. Many years ago, used airplane starting motors were used. Nowadays with a quick Google search you can find hundreds of different motor options on EV conversion websites.

I started hunting for a motor with a tight budget in mind and I ended up finding a used motor from the east coast USA somewhere.
Apparently it came out of some sort of industrial equipment. It is rated for 72V. However, when it arrived I soon realized that it is not a series wound DC motor. Instead, it is a separately excited (sepex) DC motor. What does this mean?

In a series wound DC motor, controlled current goes through the armature windings and then through the field windings. The same amount of current goes through both windings at all times because they are hooked up in series.

In a sepex DC motor, the armature and field windings are controlled/powered separately (hence the name). Most of the current goes through the armature windings. The field windings are wound much finer than in a series wound motor and requires much less current than the armature, but requires a separate control device.

Unfortunately, I had already purchased a used motor controller off eBay, an Alltrax 7245. 72 volts and a peak output of 450 amps.
This controller is meant for a series wound DC motor (or permanent magnet DC motor) because it only has one pair of motor terminals. It can only control current on one circuit. Here you can see the problem: with a sepex motor you have to control the current on two separate circuits.

Part of me wanted to purchase a sepex motor controller...until I saw their prices. The cheap (frugal?) part of me decided to try to make do with what I already have. With a whole bunch of research I have concluded that putting a constant 12V to the field windings (which will draw approximately 10A) and controlling the armature winding current with my 7245 controller should work. Should work.

Then [of course] I got thinking. Sepex motors have an advantage over series wound motors because of more control over the armature and field circuits. So what I am planning to do is to power the field with a switchable voltage - say 12V and 24V - with a toggle switch on the gear shift. Higher field voltage will produce more torque but less speed. Lower field voltage will produce less torque but more speed. Almost like an electric gear shift, no? I guess I will find out the hard way....

Charging

Obviously another important part of an EV.

Almost all electric vehicles have one battery charger that charges the entire battery pack in series. For example, my EV will have a 72V system voltage, so the "normal" thing to do would be to use a 72V battery charger. However, this way of charging only works if all of your batteries are in the same condition. If you attempt to series charge batteries that are not equal, the weaker ones will reach full charge first and then overcharge when the stronger ones catch up. The result is an unbalanced (aka weak and failure prone) battery pack.

Battery balancers can be used. Simple balancers basically shunt charging current around "full" batteries, allowing all the batteries to charge evenly. But those cost money and are not in the budget.

My solution? Individual 12V chargers. Six of them, because 6 X12 = 72V which will be my system voltage.
I bought them at Canadian Tire for half price, $30 each a while back. The guy in the store who got them from the back thought I was a wierdo.  He's probably right.

They are supposedly smart chargers, so they shut off automatically when a battery is fully charged, and they charge at 10 amps. I have been using one of them to keep my entire battery pack alive in the garage with a 2A charge.

So I will use 12 batteries in the car - six "buddy" parallel pairs in series to get 72V. Each charger will be responsible for charging one of these buddy pairs, so two batteries. Makes sense?

Batteries

...is what makes an EV go. Typically the most expensive part of an EV conversion. Not for me. I am using used Paccar Dual-Purpose truck batteries - cores that have been donated by Peterbilt Pacific Inc.
Whenever a set of four batteries are replaced in a truck, there is generally one or two that are still decent. I have gleaned 13 batteries from the core shed at work that have passed a 350 amp load test and that should get me to work and back. Here's hoping.
Here's most of them in a parallel charging array in my garage to keep them alive while they patiently wait to be abused in my car.