Level 2 Charging Stats

[Daniel2022AT]

I’m interested in actual data about Level 2 charging losses. Energy delivered from the outlet versus energy delivered into the battery. There should be some precise stats available on this. I’m interested in the 92KWH battery. I read general estimates but I’m interested in actual data.

 

[Neurio]

I’m interested in actual data about Level 2 charging losses. Energy delivered from the outlet versus energy delivered into the battery. There should be some precise stats available on this. I’m interested in the 92KWH battery. I read general estimates but I’m interested in actual data.

I'm sure there are multiple variables to account for charging loss, which people more adept at engineering than me can explain.

What do you use to charge your car? I have the Chargepoint Flex and and it tells me the amount of energy 'delivered' with each charge, so I can roughly calculate energy loss based on the battery state of charge.

For example, last weekend I charged from 10% to 80%. Based on the API website made by @segbrk, my current battery capacity is 105.25 kWh (~7% degradation over 22k+ miles). Therefore the car should have received 73.675 kWh (105.25 x 0.7). My Chargepoint said it delivered 82.23 kWh, which means there were almost 9 kWh lost. There's a chance my battery was actually at 9%, so the loss may be a little less, but it'd still be around 10%.

Is this the sort of thing you're looking for?

 

[Adnillien]

The EPA documents give a bit of a hint here since the level 2 charging efficiency is included in their overall efficiency numbers. Based on this the level 2 charging loss is between 15% and 16%. Losses come from AC voltage boost and AC to DC conversion along with resistive losses and an thermal management that is required. This number seems typical for most EVs.

 

[segbrk]

The car (and mobile app) also tell you how many kWh were added in the current charge session. You can compare that to what your charger reports, if you have a "smart" one with that kind of monitoring. Or you can use something like the Emporia Vue to monitor your consumption further upstream at the breaker powering your charger.
I have our Lucid integration in HomeAssistant in addition to an integration for my EVSE, so I can even graph those two data points together.

 

[Daniel2022AT]

I'm sure there are multiple variables to account for charging loss, which people more adept at engineering than me can explain.

What do you use to charge your car? I have the Chargepoint Flex and and it tells me the amount of energy 'delivered' with each charge, so I can roughly calculate energy loss based on the battery state of charge.

For example, last weekend I charged from 10% to 80%. Based on the API website made by @segbrk, my current battery capacity is 105.25 kWh (~7% degradation over 22k+ miles). Therefore the car should have received 73.675 kWh (105.25 x 0.7). My Chargepoint said it delivered 82.23 kWh, which means there were almost 9 kWh lost. There's a chance my battery was actually at 9%, so the loss may be a little less, but it'd still be around 10%.

Is this the sort of thing you're looking for?

Yes exactly. I have an Enel JuiceNet controller running at 9.6 kW from the utility company which enables TOU rates. It gives the exact amount of energy delivered. I can only estimate the energy put into the battery. At a given temperature, I think our vehicles should all experience the same charging loss due to the battery design and software. We should know precisely what that is. I was estimating 6-8% loss but I don’t know it exactly. 9-10% is higher than I estimated. I don’t care about EPA estimates.

 

[Steveinarizona]

What do you use to charge your car? I have the Chargepoint Flex and and it tells me the amount of energy 'delivered' with each charge, so I can roughly calculate energy loss based on the battery state of charge.

I do also. In my market (Scottsdale AZ) I seem to be getting about 30 miles of charge for $2 on a time of day plan for my GV60P.

For comparison, the 2024 BMW 3 series (330i) gas version gets 29 mpg combined and in Scottsdale the average price for premium gasoline is about $4 per gallon. So filling up with electrons at home is about half the price of filling a BMW small sedan with premium gas. And, of course, it is way more convenient.

But given the variables (e.g., I drive like I stole it) I can't calculate vampire loss. But I have noticed that even after several days of not using it, I still seem to have 79% battery so the vampire loss on the GV60P seems pretty minimal.