OK, this will be a quick post since its time for bed but I wanted to get this up. I have been working on a BMS system for my electric car and this is what I came up with. It uses a simple PIC microcontroller and a few trim pots for calibration to measure 6 cells in series. Sounds simple but there are several catches to this problem. More on that later. For now lets bask in the glory that is LCD displaying data.
Here is a quick and dirty post of all my photos from the scooter project. I will put up a blog post explaining them some time in the near future. If you have any questions please post a comment and I will incorporate the answers in the post.
About a year ago I decided I hated parking at the Caltrain station; it was always full, you had to park far away from the platform and it cost $20 a month for the privilege. It was time for another solution. I live about a 15 minute walk away from the station so a scooter is a perfect alternative to driving/walking. The other issue was what to do with the scooter once you were at the station, I decided to make it small enough and light enough to take with me on the train. This created a bonus, now I could ride from the station up in SF to the office!
Me testing my scooter, by testing I mean goofing off & pulling wheelies
With those requirements set I started to look for components starting with the batteries. The batteries are the key component to any vehicle since they are such a determining factor, dictating the general size, shape, weight and power of the vehicle. After surfing the web for about 2 minutes I came to a conclusion that lithium batteries were the ultimate solution for my scooter. With there high power density, light weight characteristics I could have a scooter with a good range but still be light enough to be picked up and carried, something that is lacking with scooters on the market today.
More on the batteries later…
A group of 48 A123 cells ready to burn rubber
On to the motor! A friend of mine is a fan and competitor in a miniature version of battle bots. While visiting his house one day he showed me one of the motors he was using to drive a large drum with a lot of knarly looking spikes on it designed to chew up an enemy robot. Looking at the puny size of the motor I asked him what kind of power he could get out of it. Turns out that it’s a brushless out runner motor with a whopping 600 watts of power! I asked if they made anything a bit bigger… a search of hobby-lobby.com revealed a motor about the size of one of those small cokes you get on an airplane with a phenomenal 3000 watts!!! That 4 HP! I had found my motor 
More on the motor later…
The Motor next to its custom gear box
Now to the frame. My first idea was to take a razor scooter frame and just slap on a motor and batteries and go, but at the end of the day I decided to build my own frame for two main reasons. Reason one: I wanted to be as light as possible but I also needed a bit more room for the battery pack then what was available in a razor. Reason two: I have been learning how to use Solidworks 2006 and wanted to put my skills to the test. Being able to go through several revisions without building a single thing is a god send for any engineer.
The frame mostly assembled
Next time I will be talking about each of these parts in more detail. I’d appreciate any feed back or questions.
Till then,
Jos Goble
Going to get the Christmas tree in the Insight
About a 18 months ago my 1991 Plymouth Voyager people mover affectionately know as “The shaggin wagon” died. After months of being held together with duct tape, bailing wire and zip ties it finally just gave up. It was time for a new car, so I began looking around to see what was affordable. Then I remembered that a friend of mine had bought an Insight from a guy down in LA who restores them after they had been in a wreck. I got in contact with him and a few months later I flew down to LA to pick up my 2000 Silver Honda Insight. I was in heaven; it took driving to a whole new level for me. Not so much in the area of speed and performance (it has a 0.99 liter engine) but more on the side of doing the most with what you have (it’s three cylinders of fury). It’s almost like a game when you are driving, where you plan your braking ahead of time to get the most out of the regen braking system.
My friend with my new and old IMA batteries
For the first 4 months everything was going well, but then one day the dreaded IMA (Integrated Motor Assist) light came on. This light indicates that the IMA battery is having trouble. This would mean I would have to replace the IMA pack. After calling Honda and affirming it was not covered because the vehicle was a salvage title, I started looking at other options. I had a look on e-bay and found some one who had a pack from a crashed insight in a junkyard. I drove down to LA again and picked it up and went to visit my friend who let me install it at his house. Everything was going well until; you guessed it, 4 months later it too gave up the show.
Inside the Insight three-phase controller
Currently I am driving around with out an IMA system. This works however it’s incredibly show and it’s just chewing up my clutch. The twelve volt battery system also doesn’t like it much because the Insight doesn’t have a dedicated alternator, Instead it relies on the IMA battery pack to charge the twelve volt system through a DC/DC.
Now its time for a new approach; the plan is to find myself a good AC motor system and some lithium batteries in order to keep the weight down. I’m currently looking at a 75 kw motor and controller system but its still a bit up in the air at the moment. More on this to come in the future…
This is the “final” CAD of my scooter. The whole process of designing took a total of about 2 months. This time was filled with research on components and creating those parts in digital space. It took several revisions but I was able to start machining out the components on my friends tiny CNC mill and slowly piece them together.
Here I am cutting out one of the two latching brackets. This was a time consuming process because cutting stainless steel requires a slower cutting speed and finer passes. The result was beautiful.
Here I am the day of the EV rally putting the frame together. Events such as this are great for getting out of gumption traps and pulling all nighters.
This is the motor/gearbox assembly in the frame with the chain hooking around the rear sprocket.
Welcome one and all. This is a blog I decided to create in order to document my progress on the variety of projects I am working on. A bit about my self, I am a 21 year old Dutch immigrant who has been living in the United States for about 17 years now. Most people say “oh you’re an American now” but I still like to think of my self as Dutch. I am currently living in Mountain View, California (hurray for free Google wifi) and I work in the city (San Francisco). As you will soon realize I am quite fond of alternative fuel vehicles and the majority of projects posted on this blog will reflect that. I will post projects under different categories listed on the right.
Please leave comments on anything you like, dislike or just have an opinion on. However please keep comments tasteful, profanity and trolls will not be tolerated.
Lastly my spelling is atrocious, if you notice anything please don’t hesitate to comment on it and I will fix it as soon as possible.
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