Why aren't electric cars more efficient in charging?

[Elite Engineer]

I hear alot of issues with electric cars is that they lack long distance traveling ( less than or equal to an ICE), or that charging them

can be expensive. Is there a design that charges the car as it moves? For instance, a generator attached to one of the wheels that isn't connected to the drive train. This way as the car moves, the battery is constantly being recharged, like an alternator.

 

-Of course by my luck this already exists and I look like a moron now

 

~EE

[Acme]

I hear alot of issues with electric cars is that they lack long distance traveling ( less than or equal to an ICE), or that charging them

can be expensive.

'Long distance' is such a relative measure. If the car gets a person where they want to go in the time they want to get there on a charge then no worries. Do you have a reference on the expensive charging?

 

Is there a design that charges the car as it moves? For instance, a generator attached to one of the wheels that isn't connected to the drive train. This way as the car moves, the battery is constantly being recharged, like an alternator.

You have just described the perpetual motion setup widely touted by cranks. On the other hand there is regenerative braking wherin putting on the brakes does drive a generator and charge the battery.

 

-Of course by my luck this already exists and I look like a moron now

 

~EE

No harm, no foul.

[Elite Engineer]

As far as the expense cost of charging, I've only heard from people who know people, and/or the argument that charging an electric car doesn't really change the harm on the environment.

[Acme]

As far as the expense cost of charging, I've only heard from people who know people, and/or the argument that charging an electric car doesn't really change the harm on the environment.

Ah. That explains a lot. Anyway, since electric cars don't directly pollute, i.e. no exhaust, then they are not harming the environment as do cars with internal combustion engines. One could then argue that the coal-fired generating station is polluting to make the power to charge the car to drive on the road that Jack built, but one can't sort out sources once power is on the grid so that's weak because wind, solar, and hydro power also go onto the grid.

 

Across the river from me in Portland Oregon there are free charging stations, though you still pay to park just like any car; so much for too expensive. The charging infrastructure varies widely across the US so consult your local info resource. As for charging at home you can easily make the calculation using your exact power cost per/kwhr and the exact battery capacity of your specific electric car and then compare that cost and the range you get with the cost to fuel a conventional car for the same range.

More:

 

Developing Infrastructure to Charge Plug-In Electric Vehicles @US Dept. of Energy

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Charging Equipment

 

Charging equipment for plug-in hybrid electric vehicles (PHEVs) and all-electric vehicles (EVs) is classified by the rate at which the batteries are charged. Charging times vary based on how depleted the battery is, how much energy it holds, the type of battery, and the type of EVSE. The charging time can range from 15 minutes to 20 hours or more, depending on these factors.

 

AC Level 1 Charging

 

AC Level 1 EVSE (often referred to simply as Level 1) provides charging through a 120 volt (V) AC plug and requires electrical installation per the National Electrical Code. Most, if not all, PEVs will come with an AC Level 1 EVSE cordset so that no additional charging equipment is required. On one end of the cord is a standard, three-prong household plug (NEMA 5-15 connector). On the other end is a J1772 standard connector (see the Connectors and Plugs section below), which plugs into the vehicle.

 

Based on the battery type and vehicle, AC Level 1 charging adds about 2 to 5 miles of range to a PEV per hour of charging time. AC Level 1 is typically used for charging when there is only a 120 V outlet available, but can easily provide all of a driver's needs. For example, 8 hours of charging at 120V can replenish 40 miles of electric range, which is over 30% further than the average daily driving distance for vehicle owners in the United States as indicated by the National Household Transportation Survey.

 

AC Level 2 Charging

 

AC Level 2 equipment (often referred to simply as Level 2) offers charging through 240 V (typical in residential applications) or 208 V (typical in commercial applications) electrical service. AC Level 2 EVSE requires installation of home charging or public charging equipment and a dedicated circuit of 20 to 100 amps, depending on the EVSE requirements. This charging option can operate at up to 80 amperes and 19.2 kW. However, most residential AC Level 2 EVSE will operate at lower power. Many such units operate at up to 30 amperes, delivering 7.2 kW of power. These units require a dedicated 40 amp circuit.

 

Most homes have 240 V service available, and because AC Level 2 EVSE can charge a typical EV battery overnight, they will commonly be installed for EV owners' homes. AC Level 2 equipment uses the same connector on the vehicle that Level 1 equipment uses and all commercially available PEVs have the ability to charge from AC level 1 and AC level 2 EVSE. Based on the vehicle and circuit capacity, AC Level 2 adds about 10 to 20 miles of range per hour of charging time.

 

Future AC Charging Options

 

An additional standard (SAE J3068) is under development for higher rates of AC charging using three-phase power, which is common at commercial and industrial locations in the United States. Some components of the standard will be adapted from the European three-phase charging standards and specified for North American AC grid voltages and requirements. In the U.S., the common three-phase voltages are typically 208/120 V, 480/277 V. The standard will target power levels between 6kW and 130kW.

 

DC Fast Charging

 

Direct-current (DC) fast charging equipment, sometimes called DC Level 2 (typically 208/480 V AC three-phase input), enables rapid charging along heavy traffic corridors and at public stations. EVs equipped with either a CHAdeMO or SAE DC fast charge receptacle can add 50 to 70 miles of range in about 20 minutes.

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[Sensei]

Is there a design that charges the car as it moves?

There is something like that in Formula 1.

It's used when bolide is decelerating.

KERS. Kinetic energy recovery system

https://en.wikipedia.org/wiki/Kinetic_energy_recovery_system

This way as the car moves, the battery is constantly being recharged, like an alternator.

 

While movement always with constant velocity, it can not work.

But while braking, kinetic energy of car, can be collected and reused.

[swansont]

I hear alot of issues with electric cars is that they lack long distance traveling ( less than or equal to an ICE), or that charging them

can be expensive. Is there a design that charges the car as it moves? For instance, a generator attached to one of the wheels that isn't connected to the drive train. This way as the car moves, the battery is constantly being recharged, like an alternator.

 

-Of course by my luck this already exists and I look like a moron now

 

~EE

 

AFAIK the Prius (and probably others) use their gasoline engine to charge the battery. All propulsion is via the electric motor. The efficiency is maximized by always running the engine at its optimum speed, which probably makes up for conversion losses.

 

As others have said, regenerative braking exists, but what you describe is perpetual motion and that won't work.

[Enthalpy]

If you live in a country where electric cars are imported, you can hear and read very easily that they have only drawbacks. But for instance in California they sell, and not little. Would there be so many stupid buyers?

 

Cheap charging is one argument in favour of electric cars. You can make the estimate yourself. Induction might have some losses, but presently it's done through a cable - very efficient, only lengthy.