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From 0-100% 18,5kwh... Quite a huge degredation
Not if you factor in Finland's 0C average November temperature.

Then it's still only about 2% loss per 10k miles.

Mileage from the @Jonass log in post #1
Capacity loss from temperature in the @cuijpertjes article in post #13.

Everyone please feel free to double-check my math. 22.2kWh capacity when new is from Fiat's service tech training manual (click here).
 

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Not if you factor in Finland's 0C average November temperature.

Then it's still only about 2% loss per 10k miles.

Mileage from the @Jonass log in post #1
Capacity loss from temperature in the @cuijpertjes article in post #13.

Everyone please feel free to double-check my math. 22.2kWh capacity when new is from Fiat's service tech training manual (click here).
Can you share your math?

Charging is less efficient when cold. If the charger displays 18.5kwh input to the battery when temperature is 0C, most likely the amount absorbed by the battery is significantly less. For a car like ours with battery temperature control, some of that 18.5kwh goes into heating up the battery to an ideal charging temperature.

His amount of degradation is more or less the same as mine at around the same mileage. This shows significantly more degradation than the 2% per 10k miles.
 

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Can you share your math?

25°C below the lab test temperature* ÷ 3.9** = 6.4% capacity loss due to temp.

53,875 miles*** ÷ 10k is 5.39 x 2% per 10k = 10.8% loss due to mileage.

22.2kWh minus 6.4%, minus 10.8% = 18.5kWh, just like @Jonass reported:

From 0-100% 18,5kwh.





* If the 22.2kWh usable capacity spec is at lab standard 25°C, & if @Jonass was charging at Finland's Nov. avg. 0°C.

** "enhancement of battery capacity by 7.7% at 45 °C in comparison to 15 °C" (pg 7 of the link in @cuijpertjes post 13).
That's a differnce of 30°C ÷ 7.7% = 3.9, so 1% loss for every 3.9°C drop in temp.

*** "Odometer: 86704,00 km" about halfway down the @Jonass log in post 1.
 

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25°C below the lab test temperature* ÷ 3.9** = 6.4% capacity loss due to temp.

53,875 miles*** ÷ 10k is 5.39 x 2% per 10k = 10.8% loss due to mileage.

22.2kWh minus 6.4%, minus 10.8% = 18.5kWh, just like @Jonass reported:








* If the 22.2kWh usable capacity spec is at lab standard 25°C, & if @Jonass was charging at Finland's Nov. avg. 0°C.

** "enhancement of battery capacity by 7.7% at 45 °C in comparison to 15 °C" (pg 7 of the link in @cuijpertjes post 13).
That's a differnce of 30°C ÷ 7.7% = 3.9, so 1% loss for every 3.9°C drop in temp.

*** "Odometer: 86704,00 km" about halfway down the @Jonass log in post 1.

The problem is that you are confusing the energy for the two measurements. The energy coming out of the battery is going to be less when it is cold, so your correction factor would be correct if that's what he measured.

However, he measured the energy at the charger going into the car. This included power going into warming up the battery, charger inefficiency, and then power going into the battery.

The power going into the battery in this case is less than the 18.5kwh measured at the charger. From my experience with cold weather charging, I would measure ~10% more at the l2 charger than the actual battery capacity (when measured at 25C).

His actual capacity would be closer to 17kwh.
 

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Oops! I forgot that the spec we need to compare to is the EPA's 25kWh of grid power to recharge from motor shutoff to full.

However we don't know if the ambient temp was even colder, below the national average. Also, do we know if the EVSE meter measures its input like EPA does, or output?

Plus, it appears EPA uses L1, which I believe takes more power due to being slightly less efficienct than L2. In other words, L2 should show less power use, for the same battery capacity.
 

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Oops! I forgot that the spec we need to compare to is the EPA's 25kWh of grid power to recharge from motor shutoff to full.

However we don't know if the ambient temp was even colder, below the national average. Also, do we know if the EVSE meter measures its input like EPA does, or output?

Plus, it appears EPA uses L1, which I believe takes more power due to being slightly less efficienct than L2. In other words, L2 should show less power use, for the same battery capacity.
The EPA comparison is only useful if you want to compare it to the EPA 25kwh measurement. You can do that, but that's more difficult to do because it is not as easy to keep your environment at 25C through the full charge cycle unless you have a temperature-controlled garage.

I would prefer to compare it to the 22.2 kwh in the manual.
What I am trying to impress on you is that @Jonass battery does not have more than 18.5kwh of usable capacity. Let's take into account the onboard charger's efficiency. Best case, it is 90% efficient. Likely it is closer to 80% similar to other cars designed 10 years ago.
Source: Hvorfor er det så stor forskjell på oppgitt og faktisk forbruk på elbiler?

85% of 18.5kwh going into the car is 15.7kwh at the battery. Best case it is 90% efficient and the battery usable capacity is 16.65kwh.

All of this is before taking into account the weather as a factor.

This is also a good article to get you to understand the charging efficiency a little bit more:
You can see how charging it in cold weather is less efficient - it is quoting 60% efficient when charing during "very cold" weather.

You can then take this number.. Likely closer to 14 or 15kwh if he charged it at 0C or closer to 16kwh if he charged it at 25C and divide it by the quoted usable capacity of 22.2 kwh to understand degradation.

This is about 5-6% per 10k miles. Your degradation @Jonass is pretty much the same as mine at that mile. Thank you for sharing your data. Even though I would like to have slower degradation, I have observed this degradation continue consistently for my car over the past 15k miles.

By the way, the question of where the EVSE kwh is measured is not going to make much difference. L2 EVSE is 99%+ efficient (https://www.energystar.gov/sites/default/files/asset/document/Electric_Vehicle_Scoping_Report.pdf). I believe commercial EVSE should be measuring output to the car.
 

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Ya, weird, & I wonder where that little pic of a 111-mile car is from, & what the current was* but if it's legit it's yet another variable we don't really know for sure.

Without knowing voltage and current, we can't use the OBC efficiency calculation I'd been using**, like in the PushEVs link in your post #27.

* That link says "for measuring the consumption the charging was made by using a domestic socket at low current (10 A) and some on-board chargers are not very efficient at low currents."



** EPA's 29 kWh/100 mi (with charging losses) times their 87mi range, divided by 100. (or 30 & 84 respectively, for later models) = 25kWh of grid power used. Divide Fiat's service manual spec of 22.2kWh usable capacity by that, & you get 88% efficiency grid-to-battery (including EVSE & OBC)
 

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The CarAndDriver link in #27 also confirms my point* that if EPA uses L1, then using 10% more efficient L2 takes 10% less power, making it look like the battery has 10% less capacity, even at lab-standard 25°C:

"averaging 95 percent efficiency from a Level 2... a typical 120-volt wall outlet saw efficiency of, at best, 85 percent"
 

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Ya, weird, & I wonder where that little pic of a 111-mile car is from, & what the current was* but if it's legit it's yet another variable we don't really know for sure.

So without knowing voltage or current, we can't use the OBC efficiency calculation I'd been using**, like in the PushEVs link in your post #27.

* That link says "using a domestic socket at low current (10 A) and some on-board chargers are not very efficient at low currents."



** EPA's 29 kWh/100 mi (with charging losses) times their 87mi range, divided by 100. (or 30 & 84 respectively, for later models) = 25kWh of grid power used. Divide Fiat's service manual spec of 22.2kWh usable capacity by that, & you get 88% efficiency grid-to-battery (including EVSE & OBC)
Yes, that's from the EPA website. I calculated about 87% efficiency for the 500e on L2 if I understood their methodology right.

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The CarAndDriver link in #27 also confirms my point* that if EPA uses L1, then using 10% more efficient L2 takes 10% less power, making it look like the battery has 10% less capacity, even at lab-standard 25°C:

"averaging 95 percent efficiency from a Level 2... a typical 120-volt wall outlet saw efficiency of, at best, 85 percent"
Yes, so my calculation has been right. Either we compare the power stored in the battery or the wall plug draw. Both comparison yields 5-6% degradation per 10k mile.
 

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The bottom line is we still can't tell:

We're looking for a difference of 6% or less in charging power use, & according to the links above, charging efficiency varies by 35% depending on temperature, voltage, & current. & battery capacity also varies with temperature & with current.



That pic says "Manufacturer Test Comments", so it seems likely to be a manufacturer test using L2 even though the EPA uses L1. Dated 11/20/2012 with 111 miles of highway range also doesn't seem to match any new-for-2013 EV on which the EPA would be doing their own test at that time.
 

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The bottom line is we still can't tell:

We're looking for a difference of 6% or less in charging power use, & according to the links above, charging efficiency varies by 35% depending on temperature, voltage, & current. & battery capacity also varies with temperature & with current.



That pic says "Manufacturer Test Comments", so it seems likely to be a manufacturer test using L2 even though the EPA uses L1. Dated 11/20/2012 with 111 miles of highway range also doesn't seem to match any new-for-2013 EV the EPA would be testing at that time.

It is the EPA certification summary report taken from the website I linked previously for the 500e:

You can search from any car in that website:

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My understanding is that it is standard to do the tests on the dyno and then do a standard correrction factor for wind aero for the final EPA number.
Here is a read for you: The Secret Adjustment Factor Tesla Uses to Get Its Big EPA Range Numbers

I won't say we know the exact degradation, but we know to within 1 percent what it is.

In the best case, if it was charged at 25C on L2 similar to the EPA certification then we can calculate the degradation as:
(25.7-18.5)/25.7 over 54k miles. This yields 5.2% degradation per 10k miles.

If it was charged at 0C on L2 similar to what you were suggesting, it is going to be worse because you would have needed more energy to charge it on the baseline case. Let's assume it needs 10% more energy for battery conditioning (remember, battery capacity does not change here only that power is going into heating up the battery to set temperature):
(28.27-18.5)/28.27 over 54k miles. This yields 6.4% degradation per 10k miles.

I am calculating this using the baseline charge kwh on L2 that's on EPA website.

Yes, I don't know the exact number, but I am comfortable with 5-6% degradation per 10k miles estimate for his car.

This is very far for 2% per 10k miles that you have been quoting.
 

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The 2% per 10k miles I mentioned is just from the prior charge-meter reports, all at unknown temperatures. Two were around 2.3% & one was around 1.5%, for an average of about 2%.

The average is now about 3.6%, including the recent reports from @hastalavista & @Jonass at 6% each.

6% is the worst measurement I've seen.

Even at 6%, after 100,000 miles the range will be close to my US-average commute. Beyond that, I'd have to stop for a few minutes on my way home.
 

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The 2% per 10k miles I mentioned is just from the prior charge-meter reports, all at unknown temperatures. Two were around 2.3% & one was around 1.5%, for an average of about 2%.

The average is now about 3.6%, including the recent reports from @hastalavista & @Jonass at 6% each.

6% is the worst measurement I've seen.

Even at 6%, after 100,000 miles the range will be close to my US-average commute. Beyond that, I'd have to stop for a few minutes on my way home.
If that average battery degradation makes you sleep better at night, I am OK.

I do not trust the other datapoints you have because you calculated @Jonass degradation to be 2% per 10k mile too (quoted below). There are mistakes all over for that math. For all I know, all the other numbers are 3x higher too so we do average ~6% degradation per 10k miles.

I was trying to find other numbers with L2 chargers going from 0-100% so I can directly compare that to the EPA certification but I can't seem to find them. Can you point those out to me if there are any?

What's disappointing is that this degradation is about the same as the original Leaf that has no liquid cooling.

25°C below the lab test temperature* ÷ 3.9** = 6.4% capacity loss due to temp.

53,875 miles*** ÷ 10k is 5.39 x 2% per 10k = 10.8% loss due to mileage.

22.2kWh minus 6.4%, minus 10.8% = 18.5kWh, just like @Jonass reported
 

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Yes: I pointed out my error. I mistakenly used the 22.2kWh output spec, for which we don't know the power level, instead of the input spec of 25kWh, which now appears to be at L2.

No: All the other reports of 2.3%, 2.3%, & 1.5% directly compared L2 charge meters to the EPA's published 25kWh charge meter spec, so they are at least as valid as any other charge meter report.

But even the recently-claimed all-time high of 6% gives me 100,000 miles before I have to stop a few minutes for a free charge on the way home from my US-average drive.
 

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Yes: I pointed out my error. I mistakenly used the 22.2kWh output spec, for which we don't know the power level, instead of the input spec of 25kWh, which now appears to be at L2.

No: All the other reports of 2.3%, 2.3%, & 1.5% directly compared L2 charge meters to the EPA's published 25kWh charge meter spec, so they are at least as valid as any other charge meter report.

But even the recently-claimed all-time high of 6% gives me 100,000 miles before I have to stop a few minutes for a free charge on the way home from my US-average drive.
Thank you for clarifying. Let me know if you can point out to the particular user that reported that or the thread. I'd like to understand more the context and the big discrepancy.
 
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