7 3/8 x 9 1/4 T echnical / Build Your Own Electric Vehicle / Leitman / 373-2 / Chapter 11
C h a p t e r 1 1 : M a x i m i z e Yo u r E l e c t r i c Ve h i c l e E n j oy m e n t part is very similar to the experience of a lifelong stick-shift driver who drives an automatic transmission vehicle for the first time. As for the maintenance, there’s a whole lot less to do, but it has to be done conscientiously. Let’s take a closer look at each area.
Driving Your Electric Vehicle Your EV conversion may still look like its internal combustion engine ancestor, but it drives very differently. Here’s a short list of reminders:
Starting
Starting an electric vehicle conversion is a little bit of a science. There’s no need to use the clutch on startup because the motor’s not turning when your foot is off the pedal. On the other hand, there is a very definite need to have it in gear because you always want to start your series DC motor with a load on it so it doesn’t run away to high RPM and hurt itself. If you forget and accidentally leave the clutch in (or the transmission in neutral), back off immediately when you hear the electric motor winding up. The best analysis I have heard is that if your electric vehicle conversion is a lighter package (not a performance-based controller and heavy-duty motor) you can start the car in second gear without a problem since the torque of an electric motor will push the RPM (such as the Ford Ranger discussed in Chapter 10). Whereas the higher performance vehicles (such as the Porsche discussed in Chapter 10) can easily be started in fourth gear since the vehicles motor, controller, and batteries will have the necessary voltage requirements to accelerate from 0 to 60 in 4 to 6 seconds.
Shifting
If you do city driving, you’ll wind up mostly using the first two gears. The lower the gear, the better your range, so use the lowest gear possible at any given speed. However, if you do highway driving, expect to shift gears higher.
Economical Driving
If you keep an eye on your ammeter while driving, you’ll soon learn the most economical way to drive, shift gears, and brake. For maximum range, the objective is to use the least current at all times. You’ll immediately notice the difference in drag racing and going up hills—either alter your driving habits or plan on recharging more frequently.
Coasting
If you don’t have regeneration, coasting in an EV is unlike anything you’ve ever encountered in your internal combustion engine vehicle—there’s no engine compression to slow you down. You need to learn how to explain how to correctly “pulse” and when. I have ridden with drivers who floor it for three seconds, then coast, floor it, and coast. Heavy pulsing is not good for the vehicle and wastes energy. In most driving, a steady foot is better. Light pulsing is only an advantage when little power is needed.
Regeneration
Regenerative braking is a mechanism that reduces vehicle speed by converting some of its kinetic energy into another useful form of energy. This captured energy is then stored for future use or fed back into a power system for use by other vehicles. For example, electrical regenerative brakes in an electric railway vehicles feed the generated electricity back into the supply system. In battery electric and hybrid electric
273
