Published On Dec 05, 2019
This video is an overview of the electric vehicle conversion I did on my 2001 VW Passat. I'm using a 90kw Siemens AC induction motor and a drive inverter I built myself.
You can read more about this conversion at http://etischer.com/awdev
To answer some of the common questions being asked in the comment section:
- This conversion started in 2008 before the Nissan Leaf or Chevy Volt were released, the only way to get an EV was to build one. I spent about 500 hours (1 day per week for a year) getting the car to the point it was a daily driver, inspected by the Bureau of Automotive repair, and registered electric with the DMV.
- My EV conversion helped me land job at Tesla, where I was Sr. Staff Controls engineer in the Powertrain equipment engineering team, 2011-2018. I drove the car in to my interview, and gave a 30 min presentation on it. I consider it my rolling resume.
- I have a B.S. degree in Mechatronic engineering from California State University Chico. It's a 4 year program combining Electrical, Mechanical and Software engineering, it was the first college in the country to offer this degree. I'm now a voluntary advisory board member at Chico State.
- Assuming 25 mpg, and $4/gallon gas (California prices), 90k miles would be about $14,400 in gasoline. In addition, $1,000 in oil changes, $1000+ in maintenance (timing belt, water pump...)
- Cost to charge: Our electric bill actually went down once I started charging the car, because we also switched to a time of use rate plan. After midnight, electric rates were $0.03/kwh, my car gets 3 miles per kWh, and I charge at work 50% of the time. For 1,000 miles, my cost would be $5 if I charged at home 50% of the time. Rates have recently gone up to $0.09/kwh but we have enough solar generation to offset our utility bill.
- Total cost for my converted EV was $25k, fuel for 10 years and beyond is basically free. Compare this to spending $25k on a gas car, after 10 years the car's depreciation would be about $20k, and the owner would have spent $16k on gas and maintenance. Cost of ownership for a gas car would be $36k over 10 years.
- Range should be about 100 miles, but I never drove past 70 to maximize battery longevity. I was driving 50-100 miles a day for 8 years, until I retired and bought a Tesla Model 3.
- The converted car weights 3,700 lbs, about 100 lbs heavier than a stock V6 Passat . Most of the battery weight (500 lbs) was added to the rear, about the weight of 3 passengers. I had custom springs wound so the car would sit level. It now has almost perfect 50/50 weight distribution. VW also put a W12 in this car, 5,400 lbs!
- About Safety:
Yes, the ABS and airbags still work. The structure of the vehicle is unmodified.
LiFePo4 batteries are fairly inert, even after driving nails through them, they don't catch fire (unlike 26 gallons of gas in a gas tank). Brakes work awesome with disc brakes and regen brakes. Battery racks and straps engineered with 30x factor of safety.
- Not shown in the video:
I have a vacuum pump to run the brake booster, it's mounted under the front battery pack.
I also have an emergency stop button on the lower dash panel. Turning the key off will also open the main power contactors if needed as a secondary redundant shut off.
-The Passat was built with a throttle by wire system. It outputs 1.5 - 4 volts, I have my VFD programmed to detect a fault if the voltage is outside of this window (broken wire, short circuit...)
- Why didn't I use a clutch?
I wasn't sure if the bearings in the motor could take the thrust load (xxx lbs) of the clutch throw out bearing pushing on the motor shaft. Adding a clutch means adding a flywheel, which requires more machining tolerance and higher force on the taper lock fitting I was using. It would also require balancing the flywheel to 9k rpm. Most EVs that use an AC motor use a single speed gearbox.
- I also did a Mazda Rotary engine & 5 speed in my MG Midget, and a Subaru flat 6 engine in my Porsche 914.