Engineering Stack Exchange
Engineering Stack Exchange

Questions tagged [electric-vehicles]

Questions about the design and operation of electric drive vehicles, especially on-road vehicles.

67 questions
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Does an electric vehicle going downhill recover energy?

I have to model the behavior of an electric car. For this, I use these equations and I can observe by "playing" with parameters that, when going downhill at constant speed, the car has a negative consumption (i.e. recovers energy). I was wondering…
Greg82
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How do electric vehicles' motors run at high speeds above 10000rpm?

For example, for a squirrel cage induction motor, the speed of operation is given by Ns = 120*f/P depending on the number of pole pairs and supply frequency. Now the supply frequency is 50/60Hz while the minimum number of pole pairs is 2. This…
Santhosh Srinivasan
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A couple of questions about making an electric hobby car from scratch

So I'm a high school student doing some competition (a wallet-sized one, unfortunately) and I'm supposed to make an electric car. Think an RC-car, (about that size) without the remote control. I want to make one from scratch, so I decided on using…
Shashank Addagarla
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Why not use just one electric motor in a car?

Instead of using an alternator to charge the battery, and a starter to start the engine, why not just put one electric motor which is always connected with the engine? When we want to start the motor, we supply electricity to it; and when the…
user3407319
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What happens if an EV motor is stalled?

What happens if an EV's motor is stalled, i.e. prevented from rotating while attempting to accelerate? Can this result in over-current damage to the batteries, motor, or speed controller circuits etc. I know that for normal hobby DC motors, this…
user1751825
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1 answer

Can you charge an electric vehicle with two mains sockets?

I live in Britain and am considering purchasing an Electric Vehicle, EV; likely the second generation Nissan Leaf. I intend to install a home EV charger at my property, however friends and family do not yet have one. I understand that charging EVs…
James Geddes
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One Wheel Drive utility wagon

I want to add a mid-drive e-bike motor to a pull wagon. I have to carry a heavy load up ramps frequently and adding an ebike motor to my wagon would make the job a lot easier. I already decided to put the motor on the "back wheel" (non-directional)…
Alexandre Rondeau
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2 answers

Battery Swapping in Electric Cars

What are the advantages and disadvantages (technical, financial etc.) of having battery swapping system over charging stations for electric cars? As per my reading, battery swapping seems feasible for electric buses and 2-wheelers but not for cars.…
user16060
3
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6 answers

Do gears make an electric motor bike more efficient?

Electric motorbikes were sold initially on the idea that there would be lesser maintenance and would remove the requirements of the gears. Now, a lot of people like having a geared system. Some argue it makes it more efficient during cruise mode or…
albseb
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Is it viable to "convert" petrol buses to electric?

As part of sustainable transformation, a city is planning to replace its fleet of 300 petrol-powered buses (part of its rapid transit system) to electric buses. 100-each were bought 7 years ago, 5 years ago and 3 years ago. The eletric buses would…
whoisit
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How do electric motors of cars age?

I was recently discussing with a relative about electric cars. It was claimed that the motor of an electric car would age (wear and tear might be the english term?) and the efficiency would become dramatically worse after a few years of usage. While…
Martin Thoma
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How to protect users from shock hazards from electric vehicle high voltage system?

I am in the design phase of an electric vehicle. I have realised that at one point, we will need to implement protective measures to safeguard the users from shock hazards of the high voltage system. I understand that we should use an isolated…
gr3en_apple
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Is there an upper limit to how fast a self balancing one wheeled vehicle can become while also being able to safely stop?

I've recently come across pictures of segway/hoverboard like self balancing motorcycle type vehicles that were supposedly able to become as fast as a street legal scooter. I kept wondering how they would do an emergency brake from top speed. If the…
Jeffrey
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What are the tradeoffs between using hydraulic motors and electric motors?

My limited understanding of hydraulic systems is that they aren't nearly as efficient as electrical systems, and that wire is cheaper than high pressure lines. Example: In a zero turn mower, each of the drive wheels has a separate pump and hydraulic…
Sherwood Botsford
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Overhead cable vs batteries for vehicles

This mainly would concern Europe, since part of the infrastructure is already in place (trolleys overhead cables). What economic reasons prevent electric autos sans large batteries from being feasible in European cities? Lithium is considered by…
paulj
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