Electric car transmission

mobius42

Hopefully someone here has driven or owns an electric car and can answer this for me. Do electric cars have a manual transmission and if so, how do you know when to change the gears? Is there a rev counter that you use to judge it or something else? It's just that with a petrol engine you can judge by the noise of the engine, while electric cars are silent. Sorry if this is a stupid question.

towel401

Electric motors work at a very wide range of RPM's so generally don't need gears. although having 2 or 3 gears might help its often not worth the hassle and space of installing these gearboxes and they go for fixed-ratio gears instead

a common design is to put the motors directly into the hub wheels themselves and therefore having no gears at all. other electric cars have a rear mounted engine and a single ratio gear.

to reverse the motor spins backwards

Gregor Samsa

As far as I know, most electric cars only have one gear, so you don't need to worry about when to shift.

Edit: beaten to it by towel401, and in more detail too.

robtri

never owned or driven one....
but iirc, EV cars don't have a transmission.... one gear forward one gear reverse...

DublinDilbert

mobius42 wrote: »

Hopefully someone here has driven or owns an electric car and can answer this for me. Do electric cars have a manual transmission and if so, how do you know when to change the gears? Is there a rev counter that you use to judge it or something else? It's just that with a petrol engine you can judge by the noise of the engine, while electric cars are silent. Sorry if this is a stupid question.

Can you confirm what you mean by an electric car? A factory built electric vehicle? or a conversion which might be done by an enthusiast?

It really depends on the vehicle, the motor being used, amount of power available, desired efficiency, as to what way the system works. Depending on the type of motor it will have a certain torque speed curve, this is very different to the torque speed curve of a regular combustion engine.

For most EV conversions they leave the manual transmission in the vehicle, but keep it in 3rd gear most of the time. The torque speed curve of the electric motor allows them to do this.

I'm not up-todate on the latest production EV's, but as far as i know they try to minimise the amount of gearing in the system. You would want to try avoid using too many gears if at all possible, due to the losses involved. This may not always be possible, depends on what your trying to do.

mobius42

DublinDilbert wrote: »

Can you confirm what you mean by an electric car? A factory built electric vehicle? or a conversion which might be done by an enthusiast?

It really depends on the vehicle, the motor being used, amount of power available, desired efficiency, as to what way the system works. Depending on the type of motor it will have a certain torque speed curve, this is very different to the torque speed curve of a regular combustion engine.

For most EV conversions they leave the manual transmission in the vehicle, but keep it in 3rd gear most of the time. The torque speed curve of the electric motor allows them to do this.

I'm not up-todate on the latest production EV's, but as far as i know they try to minimise the amount of gearing in the system. You would want to try avoid using too many gears if at all possible, due to the losses involved. This may not always be possible, depends on what your trying to do.

I meant a factory built electric car, yes. Thanks for the replies.