ElectroClassic EV
Classic Cars Reborn into the Electric Future

AltCar Expo 2011

It’s hard to believe an entire year has gone by since the last AltCar Expo at the Santa Monica Civic Auditorium. It was pretty low key as always, but there were plenty of enthusiasts lining up for free test drives of several electric vehicle models, including the Nissan Leaf, the Mitsubishi “i,” and the Chevrolet Volt.


My only real mission this year was to get a close look at the new industry standard charging receptacles and plugs. Inductive paddles were long used to charge vehicles, but energy losses and heat generation were the Achilles heel that made direct connections more effective and efficient.  As the standard changes, entire businesses have formed around locating and replacing old paddle chargers with the new plugs.

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And here it is: The business end of the mighty SAE J1772-2009 charging connector, modeled by one of the lovely Chevrolet Volt Ambassadors. There is a joke somewhere about the illusion of the plug size relative to her small hand, but it escapes me at the moment.  My simple goal was just to confirm the nomenclature and get a few pictures of the plug so I can start thinking about locating the charging port on my car.  Ideally, it will be hidden under a flip-down license plate frame, like gas caps on those big heavy American highway cruisers your grandpa used to drive.

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Here is the simplest solution for home charging.  Those dangly wires on the right run directly into an open 110 or 220 VAC breaker in your home distribution box, and the more voltage delivered to the vehicle, the faster it will charge. The J connector and bracket is installed in a convenient location near the vehicle on either the outside of the house or in the garage. This is exactly the setup I will use.  There is also a simple adapter that offers a 110 VAC standard 3-prong household plug on one side, allowing you to charge from any regular outlet.

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Here’s a look at the Nissan Leaf dual charging ports. The aforementioned J plug is on the right and handles level 1 and 2 charging, taking between 8 to 12 hours depending on the feed voltage. Since charging EV batteries requires direct current (DC), the vehicle must convert standard AC mains current to DC using the on-board rectifier included in it’s charging circuit.  Beyond 220 VAC, it is much more cost, energy, and time efficient to just deliver DC current directly to the batteries rather than converting it from AC.

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The larger Leaf receptacle on the left is the TEPCO JARI high-voltage DC charging port, which accepts 480 volts DC and will charge the battery pack in less than an hour (according to the Nissan reps).  This fast charging protocol has been developed in Japan, and is named CHAdeMO, which is an abbreviation for “CHArge for MOtion,” and otherwise a Japanese pun for cha demo ikaga desuka, meaning “How about some tea?”  Fast charging cannot easily be done at home, and these charging stations are apparently expensive, making wider adoption by commercial and municipal concerns less urgent.

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Here is an idea whose moment has come.  It’s only a matter of time before we see Automobile Club tow trucks pulling around EV mobile charging units to rescue stranded drivers.  Using the DC fast charging port, you could be juiced up in 30 minutes while you have a cup of tea with the AAA driver.  Maybe they should build a teapot into the trailer.

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This was the Nissan Leaf battery pack lecture and demonstration.  The display above shows the to-scale top-view outline of the car, and the relative position of the battery pack. I learned that the total pack voltage is about 400 VDC, and the entire battery pack is located in the chassis, which segues nicely into the next item.

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This is called the Trexa, and is one of the more interesting products shown at the AltCar Expo for a couple of reasons.  First, this is the most practical implementation of the swappable body concept that has been on automakers’ drawing boards forever.  The idea is that the volume and weight of EV batteries make it reasonable to integrate them right into the structural chassis.  In this case, the batteries are located inside the central torque tube, making for even weight distribution and very low center of gravity.  Due to the simplicity of this design, it’s easy to scale the tube and battery pack size, as well as swap vehicle bodies depending on the application or tastes of the user.  Trexa is pitching the utility and modularity of it’s product to the military market, not so much as a specific vehicle but as a multi-application platform.

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The other reason I found the Trexa so interesting is the drive-train, which looked immediately familiar. This is exactly the HPEV AC50 motor and Curtis controller that I have been eyeballing for a long time, and using as a basis for my own drive-train and traction pack design.  It’s a huge vote of confidence in the reliability of these components being used in a vehicle that is intended to take a beating.

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The only item that trumped the Trexa was a vehicle that wasn’t even being officially exhibited: this home-built solar bicycle.  The solar collectors are pulled along on a trailer, and are wired into the DC motor in the hub of the rear wheel.  I overheard the owner describing how he cruised the city for seven straight hours on an overcast day without a single pedal stroke. That’s a future I can live with.

For the curious, here’s my post on AltCar Expo 2010.

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14 Responses to “AltCar Expo 2011”

  1. I always look forward to your latest updates. Your in-depth research and analysis are a great source of information and inspiration.

    Electric is here; 99% of the world doesn’t know, yet. When it happens, there will be a sea-change in the world economy. What happens to all of the laid-off hydrocarbon people–the internal-combustion mechanics, pipe fitters, welders, shipyard workers, etc?

  2. Thanks Joe. If I’ve inspired you, then I must be on the right track.

    It’s funny that I didn’t attend the Expo with any intention of building a blog post – I just snapped a few things that interested me. When I looked at the images, I realized there was a coherent point-of-view.

    The big oil companies are scrambling to figure it out by rebranding themselves as green-ish “energy suppliers.” Is it possible for a vulture to become a dove? As far as welding goes, I think we’ll be building cars, ships, and interstellar spacecraft until we finally transcend atoms. That might be a while.

    • Very cool project Brems. I had no idea how involved this was. I just thought you had to pull out the gas engine and drop in a battery and electric motor. Shees!

      Thanks for sharing your creation,
      Scott

      • …and miss out on all the fun and learning of a ground-up restoration? I never knew baking soda was so versatile! Thanks for the comment.

  3. I saw that bike parked by the bike valet. I went to find some paper to leave a note, and when I returned, the bike was gone. You have contact info on this person? Name or other info? I would like to connect with them and learn more about this solar bike project.

  4. I was trying to get more info on the battery packs for the Nissan Leaf. From what I know so far, they come in 48 bricks for a full pack. There is 24 lined up together. and the other 24 or laid down and stacked in symetrical piles. The voltage can vary from full charge to full depletion from 400-340 volts. I am trying to figure out how many volts each brick contains. I am guess either 6 or 12 depending on if they running the whole set in series or splitting them up into two packs of 24 in series and then running those in parallel. What do you know?

    • Hey Michel – I never spoke with the owner of the solar bicycle, so I never got any further info. Regarding the Nissan Leaf battery pack, your figure of 400 volts corroborates what they told me. I was also told that the batteries are arranged in modules of 4 cells. Beyond that, nobody there could answer many more technical questions. I do know that the batteries are produced by Nissan in Japan, but I’m inclined to think that operation is fulfilled in partnership with a third party. If you discover anything more, let me know. Thanks for your comments!

      • You on fbook? I am trying to get some more discussion about altcar happening there. I am thinking that the Nissan Leaf cells may eventually be made available as units through Nissan or third parties. I am thinking these cells, if mass produced, could make for a cheaper alternative for creating battery packs for e-motorcycles and e-bicycles, or other things like this folding electric microcar http://www.youtube.com/watch?v=jwwiVX7z1PE

      • Regarding the Leaf batteries, and any other batteries currently in mass produced EVs, I would definitely like to see them become available for sale to people like me, who cumulatively will eventually become a viable market sector for battery sales. I certainly don’t plan to stop with one EV conversion.

        If there is a fb altcar page, I’d like to visit and see what you’re up to. I liked the video. Hail to the tinkerer!

  5. What is your fbook profile link? Post or send to me via private msg on fbook.

    The one thing that I think will be interesting is to see smart chargers for the lithium cells that can be adjusted to certain script for charging.. perhaps with downloadable software to work with particular batteries. The Lithium Iron Phosphate batteries apparently have a very flexible capacity in terms of how much current they can suck up during a charge with out any danger.

    • As I understand, they will take as much voltage as you can give them. These smart chargers you speak of already exist and are integrated into any good battery management system (BMS).

      • I think yes and no. The difference is that the existing chargers do not vary in terms of voltage. For example, if i have a 36 volt pack or a 48 volt pack. There is, to my knowledge, no commercial lithium battery charger that identifies the pack voltage and then can top up to the correct voltage. This is a factor for people who ride electric bicycles and may have 36 and 48 volt packs. They end up having to get a specific charger for 36 volt packs and another for 48 volt packs, to be able to charge these batteries.

  6. You mentioned “I overheard the owner describing how he cruised the city for seven straight hours on an overcast day without a single pedal stroke.” What else did you hear them say?

  7. I got a few pictures from Altcar on my fbook picture library.


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