Outside Holder for 240 receptacle plug?

[generaltso]

about 7.7 kW/hr or 5.3x faster

Just an FYI - the charging rate is measured in kW, not kW/hr. A charging rate of 7.7kW can add 7.7kWh of energy in an hour, which is why the unit of measure is called a kWh (kilowatt-hour).

I think this would be a lot less confusing if a completely different name was used instead of kWh since people get kW and kWh confused all the time. Let's change the entire industry to start using Electric Gallon instead. "I just added 10 electric gallons of energy to my car. It took an hour at 10kW."

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[TheVirtualTim]

Just an FYI - the charging rate is measured in kW, not kW/hr. A charging rate of 7.7kW can add 7.7kWh of energy in an hour, which is why the unit of measure is called a kWh (kilowatt-hour).

I think this would be a lot less confusing if a completely different name was used instead of kWh since people get kW and kWh confused all the time. Let's change the entire industry to start using Electric Gallon instead. "I just added 10 electric gallons of energy to my car. It took an hour at 10kW."

The reason I used (in this case) kW/hr is because the car has a either a

Just an FYI - the charging rate is measured in kW, not kW/hr. A charging rate of 7.7kW can add 7.7kWh of energy in an hour, which is why the unit of measure is called a kWh (kilowatt-hour).

I think this would be a lot less confusing if a completely different name was used instead of kWh since people get kW and kWh confused all the time. Let's change the entire industry to start using Electric Gallon instead. "I just added 10 electric gallons of energy to my car. It took an hour at 10kW."

In this case there's not much difference because we are using it to charge a battery. A kiloWatt-hour is basically an "electric gallon" ... it's the unit used for billing. A Watt (or this case the kiloWatt) is the amount of energy being consumed at the moment. Consume that same amount of energy for a full hour and that's a kiloWatt-hour.

Volts x Amps = Watts.

If the car is connected to 240v service then the voltage is always 240v and that doesn't change (technically it does vary by a small amount but it is supposed to be within 5%). If the car is on say ... a 30 amp charger then 240 x 30 = 7200 Watts (or 7.2 kW).

If you were to plug the car in momentarily (say ... just 1 second) then that wouldn't be very useful because your 7.2 kW charging rate for merely 1 second is just 1/3600th of a kiloWatt ... not enough to go anywhere. So really it's the amount of charge you can add to the battery that you want to know. ... and that unit is the kiloWatt hour. That's your "electric gallon" of power.

The Extended Range car has a 98.8 kiloWatt battery pack ... but really that just means it can hold enough energy to supply 98.8 kiloWatts for just one hour. Or it could supply 9.88 kiloWatts continuously for 10 hours. Only 88 of the kiloWatts are usable (there's roughly a 10% buffer).

At a 7.2 kW charging rate it means you would add 7.2 kiloWatt-hours worth of energy if you let it charge for one hour. To completely fill the 88 usable kiloWatts worth of energy would require about 12.2 hours of continuous charging. Realistically you'd really only charge to 90% or less for daily charging. If you started with a 20% charge on the battery and want to take the car to 90% then you're only adding an extra 70% of the 88 kiloWatt hour capacity (61.6 kW/hrs). 61.6 ÷ 7.2 = about 8.5 hours.

 

[generaltso]

The Extended Range car has a 98.8 kiloWatt battery pack ...

No, the car has a 98.8 kiloWatt-hour battery, not 98.8 kiloWatts. It's a measure of the battery's capacity, not the rate at which it can charge or discharge.

 

[TheVirtualTim]

No, the car has a 98.8 kiloWatt-hour battery, not 98.8 kiloWatts. It's a measure of the battery's capacity, not the rate at which it can charge or discharge.

I just said that ... read my post above where I explain the difference between a kiloWatt and a kiloWatt-hour.

It's really not worth fussing over. If someone wants to take the shortcut and call it an 88 kW battery ... I'm fine with that because I understand that "stored" energy is measured in kiloWatt-hours (it's also the billable unit used by the utility company).

 

[generaltso]

I just said that ... read my post above where I explain the difference between a kiloWatt and a kiloWatt-hour.

Your explanation shows that you certainly know the difference, but yet in the midst of explaining the difference, you used the wrong unit to describe the battery's capacity. Sorry, I'm not trying to be difficult. It's just an unexplainable pet peeve of mine when people use kW and kWh interchangeably since they measure different things. I'll stop now.

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