Field Trip to San Dimas
On short notice, my buddy Adam asked if I wanted to join him on a quick jaunt to AC Propulsion in San Dimas. One of his videography gigs required him to capture images of their EV motor components, and he knew I’d want to tag along. But of course.
The man who showed us around was Wally Rippel, whose title at AC Propulsion is Senior Scientist. Wally has an extensive resume in the area of electric transportation, and you may remember him as one of the original designers of the EV1 from “Who Killed the Electric Car.” He was also the guest speaker in a prior post about the EVAOSC meeting. In the image above, Wally is displaying AC Propulsion’s induction motor that powers the BMW Mini-E and also the Scion eBox.
These are some of the parts that I was allowed to photograph. Inverter boxes, blowers, and other electronic drive parts were in various states of mass assembly in adjacent areas of the facility. Wally told us that while interest in the Mini-E and eBox were growing in the US, most of AC Propulsion’s contracts were overseas.
Once videotaping was finished, Wally invited us for a spin. Here you see an AC Propulsion inverter/controller being installed in a Mini-E, which was a surprisingly quick and easy process. On the road, the Mini-E was extremely quiet, and the expected high-frequency whine most AC inverters emit was nonexistent. Acceleration was very impressive, and regenerative braking slowed the car effectively without even touching the brake pedal. Wally stated that in stop-and-go traffic, the regen braking could recover as high as 17% of the battery pack charge.
Overall, it was a fun visit that left me with a couple of takeaways. The first is purely practical and gives a quick way to calculate the approximate range of an EV based on battery voltage and amp hours. The formula goes like this: Volts x Amp Hours x 4 Miles = Range. For example, taking the battery pack voltage for the HPEV AC-50 induction motor system (115.2), multiplied by the projected amp hour rating of the batteries (100), results in 11.5KWh. According to Wally, a good rule of thumb is 4 miles per KWh, which multiplied by the previous 11.5 results in an approximate 46 miles of range. By the same token, 200Ah batteries would double that range. Handy.
The second thing was getting to see a real EV start up company in operation. They’re not Nissan or Chevy, but they are part of an emerging new paradigm that gives me great hope. Wally has devoted his entire career to the feasibility of electric transportation, and he’s still carrying the torch. He expressed sincere interest in my project, and now I’m even more inspired than ever.