Saturday, February 26, 2011

The Controller: Curtis 1238 Series

In my own independent research, I also chose a similar motor/controller combo as ChargeCar's setup.  Some of you know, I have been planning on building an EV for years and the reason that I started in 2009 with an electric bike because I didn't have the funds at the time to do a car. Plus I figured if I screwed up royally, it would be on a much smaller, and less costly scale. Fortunately the ebike project worked very well and got me 5500 miles or so before I needed to do any maintenance. And that maintenance was directly related to the fact that the original SLA battery was shot. I'm currently wrapping up the upgrade to LiFePO4 [which will last many years] and I'll be on the ebike again in the Spring for my daily 19 mile round trip commute.

I only found out about ChargeCar last summer. This was back when I was still going to convert my black Z24. At the time I was looking at the AC-30 / Curtis 1238 combo, but now that I decided on a CR-V, I figure the motor should be sized up a bit due to the heavier weighted vehicle, but the controller's still fine. When I found out ChargeCar was going to use the same controller and motor that I planned to use, I thought it was cool. It kind of gave me a lot of confidence that I had done my homework, and done it correctly :)

Now, let's talk about this controller [finally, right?]. This controller has a lot of awesome features. The coolest is that it's fully programmable using Curtis's Vehicle Control Language (VCL). Not only does it let you set parameters for how to control current, it also can handle two way communication, so if you want, you can program the controller to make decisions based on internal or external sensor data, GPS information, dash mounted tablet pc... and more [with some programming and electronics work of course.] In some future posts, I'll talk about some ideas I have for this, but suffice it to say that this car could provide a decade of entertainment for me as I refine and invent new things to do with this functionality.

Of course, the controller offers regenerative braking, which converts the kinetic energy [the motion of the car] back to electricity and charges the battery, extending your range. Normally, this kinetic energy is transferred by your brake pads to your rotors for dissipation as waste heat. The controller is also quite efficient at powering the motor which will make the car go even further on a charge. We are expecting to get between 60 (on the low end, with A/C or heat running) and 85 miles per charge with this system. This is similar to the real life expected range of the Nissan Leaf.

You can read the data sheet on the 1238R controller if you like. It gives a lot more basic information that I don't really feel like regurgitating here. Read it though, because it is worth checking out.

In my next post I'll talk about the battery we plan to use in the CR-V.

3 comments:

Unknown said...

Mike... Go Green.. great job... I did not know that electric bike of yours was a small piece in your big picture.

Mike Baysek said...

It's not really 'green' I'm going for. Green is nice, but electric, it just makes since. I hope to get people to learn that electricity as a motor vehicle fuel makes sense, even if you think tree huggers are insane.

When you have a choice of two fuels you can make a good decision about which fuel to use at any given moment. If you only drive a gas car, you will always be held hostage by the factors that cause gas prices to fluctuate (foreign demand, supply problems, political unrest, etc).

As far as the e-bike... yes. It was a small scale experiment which proved very successful. I have a lot more confidence going into doing a car now that I've seen and felt for myself, the electric experience. Even compared to my 70 MPG motorcycle, the ebike is tons more economical and lower maintenance. The ebike gets about 700 miles on the dollar-for-dollar comparison to 1 gallon of gas, and never needs an oil change or spark plugs, etc.

Mike Baysek said...

I've since learned from some people who've handled the 1238 series controller that the access to the VCL is somewhat restricted. This is not a deal breaker for me, although, a bit disappointing. Basically, Curtis can program the thing with VCL but they don't really want end users doing it for some reason.