Energi / PHEV / EV Charging Efficiency

[SnowStorm]

This topic is for discussion of charging efficiency, that is, the total energy needed to charge versus that used to run the car (energy out of the battery).

[SnowStorm]

Here's my answer to oldbeyondmeasure's post about charge efficiency.

 

I did not include charging efficiency - I haven't taken any measurements.  70% seems quite low but I did see an undocumented article saying efficiency could vary between 70 and 90 percent.  Another article here references an EPA document that indicates the charge efficency for a Tesla Model Y at 88%.  That would make my cost about 3.4 cents per mile.  You should see if you can get lower electricity rates at night - so called time-of-use charges.

 

 

[oldbeyondmeasure]

On 9/22/2022 at 5:03 AM, SnowStorm said:

Here's my answer to oldbeyondmeasure's post about charge efficiency.

 

I did not include charging efficiency - I haven't taken any measurements.  70% seems quite low but I did see an undocumented article saying efficiency could vary between 70 and 90 percent.  Another article here references an EPA document that indicates the charge efficency for a Tesla Model Y at 88%.  That would make my cost about 3.4 cents per mile.  You should see if you can get lower electricity rates at night - so called time-of-use charges.

 

 

Thanks for citing the two articles, they are useful.

A Tesla Model Y will likely be using Level 2 charging, which is more efficient than the Level 1 charging that I am using. 

The time-of-use rate is a good suggestion but I would pay much more to run the house air conditioner during the peak period than I would save by charging the car at night. Running the air conditioner on a hot day for 90 minutes will consume about as much electricity as a full charge of the C-Max Energi from 0% to 100%. In the recent Southern California heat wave, we were running the air conditioner for as long as 12 hours per day and for five hours per day during the peak time period (4 PM to 9 PM). So I will stick with the electricity rate that doesn't change between time periods and pay more to charge the car.

[cr08]

On 9/24/2022 at 8:27 PM, oldbeyondmeasure said:

Thanks for citing the two articles, they are useful.

A Tesla Model Y will likely be using Level 2 charging, which is more efficient than the Level 1 charging that I am using. 

The time-of-use rate is a good suggestion but I would pay much more to run the house air conditioner during the peak period than I would save by charging the car at night. Running the air conditioner on a hot day for 90 minutes will consume about as much electricity as a full charge of the C-Max Energi from 0% to 100%. In the recent Southern California heat wave, we were running the air conditioner for as long as 12 hours per day and for five hours per day during the peak time period (4 PM to 9 PM). So I will stick with the electricity rate that doesn't change between time periods and pay more to charge the car.

 

Another reason for charging off-peak other than cost is charging when it is cooler out especially in warmer climates. My electric provider doesn't do TOU rates. Just one flat rate 24/7. I still schedule mine to charge after midnight to help with temps. Just an FYI.