[TrngMchn]

No problem....
Company that builds EV and has no buffer of any kind is Modern Lemon engineering....please forgive my ignorance....
Now reason why this PID is behind special access on ID4 is not something I can elaborate...but if you insist it is there and not just that but the date when it was assembled and what was AH after it finished curing process and testing.
I do agree with you that Government should mandate this to be available to any customer who is on market to buy used EV.
Good luck and if you become ID4 owner....welcome to the big community where we share and learn from each other .

Hi. thanks. I'm still leaning toward the ID4. of course, now there is another problem... To find one that is not above, or WAY above, MSRP.. haha ... if I just wait a while I'm sure I can save several K$.

techie blather below:

Meanwhile, Very true I don't know the Ah of the Chevy battery just after it finished the curing process and testing. More's the pity. But I bought it "new" ... All I know is the first time I fully drained the battery, using "normal" driving for me. That was some time in 2019 (bought car March 2018). The kWh the battery gave going from the "100% full" point to the "0%" point was 58.4 kWh. (of course, Chevy has a buffer at both ends. but who knows what it is, or if they can change it as the battery ages , with software.). In Jan 2020 I bought the OBD reader and the internally reported Ah value gave 58.0 kwh using the assumed formula. That seemed reasonable. Today the value is 53.8 kWh, and my range does seem to have shrunk a bit. (but ... hard to be sure). If true, that is too much degradation for me. 7% in about 20K miles.
I do wonder how Chevy makes the estimate of the available Ah as the battery changes over time. It's not like they drain and refill the battery while I'm asleep. I suspect that Chevy has an average relation between the Ah drawn and voltage for each cell. So even though I am not completely draining the cell, They can see that the voltage for a given Ah of drain is getting lower, thus there are fewer Ah available. Not completely accurate, but worth something. And they must have one of these calibration curves for each temperature and each discharge rate. Ha Ha. No fun. I wouldn't be surprised to find that in reality I have lost 10% of my battery, or even just 3% ...
And now I think of it, Chevy can't know exactly how much battery buffer there is, as the battery gets older and the cells change. Not without draining the buffer out at the bottom, or worse, trying to fill it at the top. Wow. makes me feel nostalgic for those truly non-linear and not accurate gas tank gauges. At least once one learned the pattern, it usually stayed the same.

 

[voxel]

But I'm not sure this is the cause of the loss in capacity in car batteries.

We are basically talking about the same thing. There's capacity and "usable capacity" (when IR gets too high and the battery effective becomes a power source for lightbulbs only).
So a 82 kWh battery might still have 75 kWh capacity after 20+ years but the IR is so high that it is completely UN-usable for an EV.

IR is the measurement I want. Usually some reference temperature + load when the battery is new and over time the battery ages and the IR increases.

After all, the I^2R loss to heat is dependent on the current draw during discharge , and will be small if you drive slow enough. It's also possible that our degradation is due to a decrease in the amount of Li that one or the other electrode can store. In other words, lithium that gets stuck in one electrode or the other due to parts of the electrode that are no longer connected to the external circuit. This doesn't show up as IR loss.

This "lithium that gets stuck in one electrode" is the dendrite problem. They form on the anode (I think cathode too?) over time. Nobody knows exactly why. It causes shorts. It causes higher IR and loss of usable capacity because lithium ions no longer flow as freely/quickly and fewer of them too.

 

[TrngMchn]

Hi. thanks for that. I didn't realize the series resistance could get so high while the capacity was still acceptable. I suppose car batteries that degrade in that way could be resold as household backup batteries where the max draw could be arranged to be 4kW , or less.
Anyway, if its the IR you want, it should be easy to get. If the battery cells voltages are available on the bus (they are on the Bolt), then you can do the test in your driveway. Get the battery to some particular state of charge (say 100% or 50%) apply a fixed load by maximizing the heater output (should be constant over the years) and measure the cell voltages. All you have to control is the weather to get the same temperature.

 

[SunWizard]

If the battery cells voltages are available on the bus (they are on the Bolt), then you can do the test in your driveway.

Yes they are available on the OBD2 port with a dongle. The apps we have to do this are very poor at the moment, I may have to write a better app (which has been my job for 43 years, since way before they were called apps.)

 

[John411iD]

So I checked (using OBDEleven software and dongle) my Max Energy Content today with about 10K miles and it say 73100Wh (73.1KWh). That’s about a 5% loss.

Car Scanner Elm Obd2 also shows this value - Maximum Energy Content of Traction Battery Wh. It fluctuates a bit every day, probably related to battery pack temperature, who knows...

There's also Total Accumulated Charge kWh and Discharge kWh, if someone wants to assess charging losses.

 

[VW TECHNICIAN]

Car Scanner Elm Obd2 also shows this value - Maximum Energy Content of Traction Battery Wh. It fluctuates a bit every day, probably related to battery pack temperature, who knows...

There's also Total Accumulated Charge kWh and Discharge kWh, if someone wants to assess charging losses.

What was your stationary voltage....temperature and when was balancing done last time...and what was your pack IR?
There is multiple special access engineering that will give you way more information...but i don't think legally you will be able to get it. Because OBDELEVEN is obligated to follow VW ODIS guidelines to stay certified.

 

[VW TECHNICIAN]

Yes they are available on the OBD2 port with a dongle. The apps we have to do this are very poor at the moment, I may have to write a better app (which has been my job for 43 years, since way before they were called apps.)

Having dedicated app on tablet for onboard telemetry screen would be great.
Most of aftermarket apps are not really designed for EV. and most of the PIDs are used from ID.3 and some formulas are incorrect to represent true values.

 

[VW TECHNICIAN]

Car Scanner Elm Obd2 also shows this value - Maximum Energy Content of Traction Battery Wh. It fluctuates a bit every day, probably related to battery pack temperature, who knows...

There's also Total Accumulated Charge kWh and Discharge kWh, if someone wants to assess charging losses.

Is there a way to make screen picture and post....I'm interested on PID and formula that show this value.
I'm talking about car scanner app.

 

[John411iD]

 

[VW TECHNICIAN]

I still need PID car scanner is using and the formula used to show wh.
Temperature .... SOC and how long was ID4 left in off position after charging are important before you take this measurement.
Pack IR changes with SOC....temperature. PID that was used and formula from car scanner app is what I need.

 

[VW TECHNICIAN]

Which of this 2 pids car scanner is using?

		"222AB2", // HV battery max energy content Wh
		"222AB8", // HV battery energy content

 

[TrngMchn]

I still need PID car scanner is using and the formula used to show wh.
Temperature .... SOC and how long was ID4 left in off position after charging are important before you take this measurement.
Pack IR changes with SOC....temperature. PID that was used and formula from car scanner app is what I need.

VW Tech: Do you think it the car recalulates the estimated battery capacity each time the scanner asks for the value in 222AB2?
I had guessed that 222AAB2 would be memory position that always has the latest estimate (calculated at some point) stored in it and that the scanner just gets this value without any new calculations on the part of the cars computer.
But actually, it might be better if the Wh or Ah response was re-calculated when asked for. If I turn
off the car at 50F and then a cold front comes through dropping the temp to 0F, it would be nice if the estimated battery capacity was adjusted in the morning. If so, I think the "guess-o-meter" distance should also change overnight as the temperature changes. I have never noticed that, but then, I can't say it didn't happen.

 

[VW TECHNICIAN]

VW Tech: Do you think it the car recalulates the estimated battery capacity each time the scanner asks for the value in 222AB2?
I had guessed that 222AAB2 would be memory position that always has the latest estimate (calculated at some point) stored in it and that the scanner just gets this value without any new calculations on the part of the cars computer.
But actually, it might be better if the Wh or Ah response was re-calculated when asked for. If I turn
off the car at 50F and then a cold front comes through dropping the temp to 0F, it would be nice if the estimated battery capacity was adjusted in the morning. If so, I think the "guess-o-meter" distance should also change overnight as the temperature changes. I have never noticed that, but then, I can't say it didn't happen.

We can only guess car scanner doesn't give you information what pid is used for showing this value. I have used for very little time car scanner and it is grayed out to see pids or formulas to show you value for specific pid output...and most of them are not working or showing wrong values. Hopefully developer will figure it out and update to have better readings in the future.
Ross-Tech.com and obdeleven are only apps i would suggest at this time......later maybe car scanner will improve.

 

[ID.Furkan]

Which of this 2 pids car scanner is using?

		"222AB2", // HV battery max energy content Wh
		"222AB8", // HV battery energy content

222AB2

222AB8 shows.. not much

222AB2 comes "close" to my calculated usable battery capacity.

Will compare the values with obd11 some day

 

[SunWizard]

Here is a new data point confirmed by VW: An ID.3 with 8% degradation after 14 months/16,000 miles (with first 9000 mostly DCFC.) It shows that "A Volkswagen service center conducted a special charging/discharging procedure and using its equipment, determined that the state-of-health is at 92%." which also was close to the the Car scanner app results. This is a little higher than expected, but points to faster degradation caused by DCFC like VW warns:

Volkswagen Confirms 8% Battery Capacity Degradation In This ID.3

The case of an early VW ID.3 1ST that appeared to lose 7.5% of its initial battery capacity after the first year of use is back - Volkswagen tested the car.

insideevs.com

 

[mochalatte]

Here is a new data point confirmed by VW: An ID.3 with 8% degradation after 14 months/16,000 miles (with first 9000 mostly DCFC.) It shows that "A Volkswagen service center conducted a special charging/discharging procedure and using its equipment, determined that the state-of-health is at 92%." which also was close to the the Car scanner app results. This is a little higher than expected, but points to faster degradation caused by DCFC like VW warns

Huh! Watched the YouTube and it is PID named "Maximum energy content of the traction battery" that he used from the Car Scanner app. I just checked mine and I'm at 74447.94 Wh on my battery, a 3.3% degradation after 5 months and 4125 miles.

My charging history FWIW: All my charges have been Level 2 (24 Amp most of the summer, but back to 40 Amp now) except 6 DCFC charges done at EA and two charges done with the Level 1 included with the car. The car was delivered to me at near 100% and I've only charged to 100% once myself. My SOC target is almost always set to 70%.

 

[VW TECHNICIAN]

Here is a new data point confirmed by VW: An ID.3 with 8% degradation after 14 months/16,000 miles (with first 9000 mostly DCFC.) It shows that "A Volkswagen service center conducted a special charging/discharging procedure and using its equipment, determined that the state-of-health is at 92%." which also was close to the the Car scanner app results. This is a little higher than expected, but points to faster degradation caused by DCFC like VW warns:

Volkswagen Confirms 8% Battery Capacity Degradation In This ID.3

The case of an early VW ID.3 1ST that appeared to lose 7.5% of its initial battery capacity after the first year of use is back - Volkswagen tested the car.

insideevs.com

Tesla will throttle fast DC charging once you hit 20 000 kWh on fast charging and it will be less SOH than ID .....
What really kills battery is high speeds on Autobahn where you calling for a lot of current and it will increase as HV DC peaks voltage drops. And 9000 fast DC charging sessions are quite amazing that he is doing 8% degradation.

 

[p7wang]

Tesla will throttle fast DC charging once you hit 20 000 kWh on fast charging and it will be less SOH than ID .....
What really kills battery is high speeds on Autobahn where you calling for a lot of current and it will increase as HV DC peaks voltage drops. And 9000 fast DC charging sessions are quite amazing that he is doing 8% degradation.

Wow, that is only about 70k miles... them Tesla slows down your SuC rate? I guess best to stay away from used Tesla.

 

[VW TECHNICIAN]

62 kWh vs 82kwh will need more time to get to 8% losses.

 

[ChristophW]

I just checked mine and I'm at 74447.94 Wh on my battery, a 3.3% degradation after 5 months and 4125 miles.

If I recall correctly, the degradation in the first year is believed to be steeper than later. Sort of a very shallow hockey stick graph where the business end starts at delivery date. For full data on 6000 EVs see GeoTab.