Tischer's Inverter for the Siemens motor built for Ford

Tischer's EV project

New Top speed


New speed record, 105 MPH!

Top speed was tested on flat ground in 5th gear. Current from the battery was 216 amps.

Dyno Result: 83.5 hp
Weight: 4010 Lbs

Offical weight of my Passat (including driver) is 4200 lbs

Non-official dyno reading of 83.5hp (running daily driver mode, 95% power)

Results from this test were within 1% of the average. The average was made up of 10 runs 0-60 in both directions. There are other torque/current profiles I have created which produce higher hp numbers, but 95% current limit has proven reliable, and that is likely what will be used for production. This is horsepower measured at the wheel, which includes drivetrain losses.

I have 4 performance levels selectable from the LCD Keypad:

Top speed: 98.6 mph


New speed record, 98.6 MPH!

The car was still accelerating, it will easily break 100 MPH on flat ground now. The 90hp TDI Passat has a top speed of 112mph, my new goal is to beat it!

280 Amps @ 280 Volts

I installed an Ammeter to measure battery current. I can peg the gauge at +300 Amps, but for reliable daily driving, I usually limit current to 260A. I can also peg the gauge at -100 Amps.

Based on the 83.5 Hp reading at the wheel, and the 105 Hp (280A x 280V), my overall efficiency is around 80%.

150% Torque


(This was filmed on a closed section of road in a construction zone with no other cars around). Keep in mind, I don't have a clutch, this is pure low speed torque.

I can do a pretty respectable burnout using 1st gear!

Trending software

2010-05-29 updated acceleration data.

Here is a graph showing 0-60 in 14 seconds (6800rpm) only using 2nd gear.

DC Bus Voltage (0-400 VDC)
Motor RPM x 20 (0-8000 RPM)
Motor current (0-400 Amps/Phase)
Throttle position (0-160% torque demand)

My DC Ammeter is scaled -100A to +300A, and I can peg the needle in both directions! You can see the battery voltage starts at 320v, sags to 280v, then jumps to 360v during regen. Regen torque/current is programmatically limited to keep the battery voltage below 370v.

60mph = 6800 rpm in 2nd, 4400 in 3rd, 3300 in 4th.

Here is a comparison of my Siemens motor vs. other EV motors. The data in the graphs were taken from manufacturers specifications. As you can see, the Siemens motor has the highest hp value, and has the most area under the curve.

Recharge speed: 14 miles per hour

The inverter and battery performace has been very consistent. A 25 mile trip to work brings the battery from 328V to 308V (about 12.3 volts per cell). I typically recharge using 10 amps for 3h 20min at 230 volts. I can charge twice as fast at 20 amps which equates to about 14 miles per hour (hour of charging).


Download my EV Calculator spreadsheet
From my calculations, 0-50mph should take 13 seconds. I am actually doing it in 10.5 seconds, so I beat my goal, and also beat the Ford Ranger EV (11.6 seconds)! The Ford Ranger EV effeciency is rated 356Wh/mile @ 60mph, 237Wh/mile @45mph.