Three years ago I wrote an article about my Heinkel Kabine EV conversion. I’d like to give an update about what has gone well, what has not, and what I would do differently if I were to convert another car today.

Converting my Kabine to an EV has been the best improvement I’ve made to my car- and I’ve tried a lot of things! I’ve owned the car for 13 years and tried many carburetor changes and other enhancements to make it run better. I typically use my car one or two times a week during the warmer months, with an average distance of 10-15 miles (16-22km) round trip. For these trips the car is excellent. The car has a range of 53 miles (85km), but I’ve never gone more than 40 miles (65km) on a single trip. It will take me as far as I want to go.

The Good

• Driving: The car is quick and easily reaches cruising speed. The car is completely quiet until you get about 40 mph, when you hear a slight whine from the hub motor magnets. You can easily hold conversations in the car, it doesn’t vibrate, and it doesn’t smell like exhaust fumes.
• Braking: The brakes are also much improved, as I have a motorcycle disk brake on the back wheel that doubles as the parking brake. When I’m driving, I use the disk brake for extra stopping power.

The Bad

• The Swingarm: I didn’t make my original swingarm strong enough. It was single-sided and it bent when I hit a pothole, so I straightened it and reinforced it. Coming back from a car show in 2024 I hit a deeply depressed storm drain and totally bent the swingarm. I had to put the car on a trailer and bring it home. I repaired it by fabricating a robust, double sided, 2 shock swingarm made from 2”x1” rectangular steel 4mm thick steel tube. I should have done this in the first place.
• Cold Weather Performance: When it gets too cold (below 3c) the range decreases and the car can shut down under a heavy load. I made a battery pack heater and now I get acceptable performance, but at a reduced range.

What I’d do Differently

I’m building another Heinkel Kabine- this time a traditional restoration with a 200cc engine! However, if I were to build another EV I would make a few improvements:

• Batteries: I used 24 Lithium Iron Phosphate (LiFePo4) prismatic cells arranged in series to achieve 72 volts. These batteries have a “C” factor of 3, which means they can output three times their amperage rating for a short period of time, which is helpful when you step on the gas to go up a hill or just want to go fast (who doesn’t!) I can max out the amperage if I floor it and try to go up a hill with two people in the car. I chose LiFePo4 cells for safety reasons; they  won’t explode like Lithium-Ion cells can. If I were to make another Kabine EV I would choose higher amperage batteries with a higher C factor so I never run out of power. Lithium-Ion cells have a 10C rating, which means that they would satisfy any peak amperage draw. They also have a smaller footprint. The same size Lithium-Ion pack would double my range (at more than double the cost!).
• Components: I’d use smaller components to keep all the electronics in the gas tank area or behind the firewall. I used traditional auto EV components in my build; I’d switch to those used in motorcycles and scooters which are smaller. I would also use a Fardriver controller rather than the Kelly controller I have in my car( a controller tells the motor how to use the power it gets from the battery). They have far more tuning options and a much larger community of people who can help you if you have questions. It’s also TŮV certified so it would make passing your TŮV (or MOT) with an much easier.
• Swingarm: I’m an expert on swingarms now- it only took me five tries to get it right! I would go with a double sided swingarm to support the 8kw hub motor.

What’s Next

EV’s are great platforms for tinkerers, since most EV tinkering involves changing settings on your smartphone app. Hot engines and greasy hands are a thing of the past.

I just finished adapting my Campi-style trailer to work with the car. I built the trailer for my Heinkel Tourist and it’s 20% larger than a traditional Campi, which means it’s a little too big to pull comfortably behind my scooter. For my short trips to the store and the beach it should be perfect.

I’m also toying with the idea of converting a Heinkel scooter to be an EV. If I can find a basket case at the right price it might be in my future.

Would an EV Be Right for Everyone?

If you are happy with your car, why change it? But if you have a three-wheeled car that you like the look of but don’t like to drive, it could be just the project for you. If you have any questions, please feel free to email me at Shawn@techdesignworks.com and I will be happy to help you with your project planning.