Top Speed

So, how fast can a DIY electric car travel? In the above video, we see the White Zombie hit 126 miles per hour in the quarter mile.

The Electro-Metro has a much more humble top speed.

On a DC electric motor system, rotational speed of the motor (RPM) is directly proportional to voltage. The higher the voltage, the faster the motor spins. The easiest way to get higher speed is to have more cells in series to create a higher system voltage.

The original battery configuration for the Electro-Metro was simply six 12V batteries in series for a 72V system. That was great for about a 45 MPH top speed, and worked well for my use in my town.

I later experimented with some other battery configurations, including 144V, which was 12 x 12V batteries in series. At 144V I was able to go at least 73 MPH. That was in a 55 MPH zone, and I probably could have still gone a few MPH faster, but I also knew where law enforcement commonly parked…

Driving at high speeds does tend to draw a lot of current, mostly due to air resistance. The faster you drive, the harder the air pushes back, and the more energy you use. Driving 55 instead of 70 can save a significant amount of power.

A home-built electric car can go as fast as budget and other design constraints allow for. It’s not uncommon for electric drag racers to use DC motors. To learn more about FAST electric cars, check out the National Electric Drag Racing Association!