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Engineering Stack Exchange

Questions tagged [electric-vehicles]

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

56 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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1 answer

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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3
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1 answer

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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3
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4 answers

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 motor bikes were sold initially on the idea that there would be lesser maintenance and it 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…
albseb
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What are the IEC IP standards/code for electric vehicles?

What an end consumer should know about the level of IP protection provided for a vehicle against hazards which include but not limited to environmental factors, thermal runaway in batteries, etc.
lousycoder
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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 will happen if we place a couple of separate, small stators around a long rotor instead of 1 large stator around a short rotor?

My original theoretical consideration was using the electric motor's rotor as drive shaft in a car. It led me to this question: "What will happen if we place a couple of separate, small stators around a long rotor instead of 1 large stator around a…
serekani
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Finding Supply/Nominal voltage for Torque Motor BLDC

I'm a bit confused by torque motors datasheets as it never mentions any nominal voltage. I would like to run a torque motor on a 24 V battery. The required max torque is 150 Nm (=21000 oz-in) and max speed 15 RPM. (=1.57 rad/s). I have found a motor…
Rusoiba
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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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Could a reciprocating engine be powered by electric arc instead of combustion?

The heat of a lightning bolt causes the surrounding air to rapidly expand causing thunder in the process. A reciprocating combustion engine ignites an air fuel mix to use the rapid expansion created in the process to build up pressure and use that…
maklemenz
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