Drive battery degradation . Houston, do we have a problem?

[anko]

Yesterday, my wife took the car to work without preheating. Ended up with 99.13% (0.2 Ah below SoH). This morning I took it after preheating. Ended up at 100,73% (0.2 Ah above SoH)

And in the evening, on my way home, I did not preheat. Ended up with almost same end result (100,9%, 0.2 Ah above SoH).

 

[anko]

Dropped back to 26.3 last night, within 900 km / 3 weeks after an increase from 26.0 to 26.8 via DBCAM :?

 

[elm70]

Yesterday, my wife took the car to work without preheating. Ended up with 99.13% (0.2 Ah below SoH). This morning I took it after preheating. Ended up at 100,73% (0.2 Ah above SoH)

And in the evening, on my way home, I did not preheat. Ended up with almost same end result (100,9%, 0.2 Ah above SoH).

Assuming you used the keyfob hack for preheat ...
It is looking like that also for your PHEV, the preheating energy consumed is not properly recognize by the BMU, else it would be impossible to have 100.9 SOC after ending of the preheating process ... right ?

I did check this again, but not in 100% exact condition, if the preheating via the WiFi is visible by the BMU .. and apparently it is :
the Car got fully charge overnight, then it had a rest of 2h ... then it got a WiFi preheat ... and the battery before usage was 31Ah @4.063v (SOH is 33.9Ah) ... so the 2.9Ah missing from 100% is consistent with preheating plus the classic 0.5Ah drop from 100%

So ... does it means that using the keyfob hack for preheating could fool the car about the real SOC

I guess ... for "trick" the BMU, for let it believe the car has a better SOH then real .. it would be needed to use the preheating keyfob hack while or just before the car get charged .. so the charging process would be looking longer then BMU would assume
As well ... preheating after charge should be done via WiFi, else the BMU will see less usable capacity

 

[anko]

Yesterday, my wife took the car to work without preheating. Ended up with 99.13% (0.2 Ah below SoH). This morning I took it after preheating. Ended up at 100,73% (0.2 Ah above SoH)

And in the evening, on my way home, I did not preheat. Ended up with almost same end result (100,9%, 0.2 Ah above SoH).

Assuming you used the keyfob hack for preheat ...
It is looking like that also for your PHEV, the preheating energy consumed is not properly recognize by the BMU, else it would be impossible to have 100.9 SOC after ending of the preheating process ... right ?

Hang on, I said I did NOT preheat ;-)

Also, when preheating via FOB, I can see both Ah and SoC go down.

SoH is supposed to be calibrated from time to time by applying 230 volt charges. Pre programmed trend line based SoH can be to low or to high. When to low, it requires SoC > 100% before it will be calibrated upwards. So, by itself values > 100% are not that unexpected. Or are they?

My last drop of 0.5 was after I had values << 100%.

 

[elm70]

This morning I took it after preheating. Ended up at 100,73%

Hang on, I said I did NOT preheat ;-)

Also, when preheating via FOB, I can see both Ah and SoC go down.

SoH is supposed to be calibrated from time to time by applying 230 volt charges. Pre programmed trend line based SoH can be to low or to high. When to low, it requires SoC > 100% before it will be calibrated upwards. So, by itself values > 100% are not that unexpected. Or are they?

My last drop of 0.5 was after I had values << 100%.

Actually from the post above I got you did once preheat and once not ... and after preheat you got 100.7% SOC .. which would be impossible, since the preheat power is above the charging power .. so SOC after preheat should be less then 100%

Anyhow ... the main difference is that you preheat with the battery still connected to the charger, which is able to charge the car.
In my case, my car is still connected to the charger, but my charged has lost already the 220v power due to timer between the wall plug and the charger.

About the SOC more or less then 100% after a full charge ... I still don't have any idea if this impact or not the SOH
I would assume that full charge is controlled ONLY by the max voltage per cell (it would be very wrong to charge the battery using the assumed SOH and SOC) ... and possibly if the charging current is monitored, if the charging current in Ah is more the the delta SOC ... then SOH should be increased .. else if delta is negative .. SOH should be reduced
Even if it is correct to measure only the capacity while discharging a battery, in Lithium battery the charging current is very close to the discharge current, especially at charging and discharging rate below 0.3C (with charging/discharge time over 3 hours) ... so maybe both charging and discharging current ... plus the voltage at rest .. is used by the BMU for update the SOH

 

[anko]

Actually from the post above I got you did once preheat and once not ... and after preheat you got 100.7% SOC .. which would be impossible, since the preheat power is above the charging power .. so SOC after preheat should be less then 100%

Sorry, I meant preheat -> drive -> charge > end up with 100.7%

 

[anko]

I think it charges up to 4.10 volt regardless of everything else.

While doing so, it takes:
- SoC at beginning of charge
- Existing notion of SoH
- Amount of energy added

To keep track of SoC during the charing process in relation to existing notion of SoH. If SoH was 28 and SoC was 25%, then you would expect SoC to reach 100% when (the equivalent of) 75% of 28 Ah has been added during the charging process. If more is added before 4.10 volt is reached, SoC will rise above 100%. If less was added, SoC will stay below 100%. If SoC at end of charge is structurally low (or structurally high) the notion of SoH can be adjusted by the BMU.

I think it will not look at SoC directly after charge, as it usually sinks a bit. When new, I saw 107+% on a regular basis, immediately after charging had completed. To drop significantly in the next few hours. Lets not forget, the DBCAM doc says several criteria need to be met before 230 volt charges can be used to calibrate SoH value. Maybe the car needs a good rest after the charge. And maybe one before as well ;-)

Also, what I cannot explain from the above is the jumps in SoC that you see during cell balancing. Yesterday, I saw +3.5% during last phase balancing. Can't explain. Unless ... that was the last charge before I lost 0.5 Ah. Adjusting notion of SoH down would result in adjusting notion of SoC up. But the drop of SoH was only visible the next day. Not directly sat the end of the charge.

 

[mellobob]

Yesterday, my wife took the car to work without preheating. Ended up with 99.13% (0.2 Ah below SoH). This morning I took it after preheating. Ended up at 100,73% (0.2 Ah above SoH)

And in the evening, on my way home, I did not preheat. Ended up with almost same end result (100,9%, 0.2 Ah above SoH).

Assuming you used the keyfob hack for preheat ...

what is the keyfob hack? Will it work on my Canadian/18? I truly hate using the cell phone app for this!!!!

 

[anko]

what is the keyfob hack? Will it work on my Canadian/18? I truly hate using the cell phone app for this!!!!

What is a search function? :mrgreen:

http://www.myoutlanderphev.com/forum/viewtopic.php?f=11&t=2118

 

[mellobob]

what is the keyfob hack? Will it work on my Canadian/18? I truly hate using the cell phone app for this!!!!

What is a search function? :mrgreen:

http://www.myoutlanderphev.com/forum/viewtopic.php?f=11&t=2118

Just to redeem my forum-foo somewhat, I did try a search before asking the question I just didn't see the thread you so kindly have linked to.

Thanks ... now I get to read 10 pages of stuff!!!

 

[anko]

what is the keyfob hack? Will it work on my Canadian/18? I truly hate using the cell phone app for this!!!!

What is a search function? :mrgreen:

http://www.myoutlanderphev.com/forum/viewtopic.php?f=11&t=2118

Just to redeem my forum-foo somewhat, I did try a search before asking the question I just didn't see the thread you so kindly have linked to.

Thanks ... now I get to read 10 pages of stuff!!!

To be fair, I know what to look for Good luck with digesting all that. I have it on my MY14 and it is a treat.

 

[anko]

My last drop of 0.5 was after I had values << 100%.

And now, it charges only to 97,81% (25,7 Ah of 26,3 Ah). Then it stops. Restarted the charging process, nothing more added. Curious to see what this wil leed to.

 

[elm70]

My last drop of 0.5 was after I had values << 100%.

And now, it charges only to 97,81% (25,7 Ah of 26,3 Ah). Then it stops. Restarted the charging process, nothing more added. Curious to see what this wil leed to.

My car normally finish to charge before I use it, as well the charger got disconnected from power at fix time in the morning.

Excluding an exceptional occasion ... which I got 102% SOC ... I always have 0.6Ah less then SOH .. voltage is always around 4.09x per cell ...

So for me is normal what you see above .. and does not implies anything special on my battery degradation ... which is lookinig constantly going down 0.1Ah every 45 days

 

[anko]

Excluding an exceptional occasion ... which I got 102% SOC ... I always have 0.6Ah less then SOH .. voltage is always around 4.09x per cell ...

Directly when charge finishes? Or upon next usage? I am talking about immediately (the second) when charge finishes. When checking on next usage, it is usually below 100%.

 

[elm70]

Excluding an exceptional occasion ... which I got 102% SOC ... I always have 0.6Ah less then SOH .. voltage is always around 4.09x per cell ...

Directly when charge finishes? Or upon next usage? I am talking about immediately (the second) when charge finishes. When checking on next usage, it is usually below 100%.

On next usage, which can be from 30min to 2h difference ...

I can't check when charging process finish, I only guess when charging is completed based on the 30min report from by WiFi power switch/monitor

I would expect this value not to change if the time between end of charging and start of the car is less then 2h which is the rest time which cause to recalculate the SOC based on voltage level.

Actually some month ago I did force the preheat 1h before starting a trip, and then I monitor the real time power from the WiFi switch .. so I start the car few minutes after the charging process was completed, and still SOC was below 100%

Only once the DOG did report me a SOC at 102% ... and this was around 1h after the charging was completed.

PS:
I guess with your adapters, only you can measure the SOC while the car is charging ... or ... maybe the DOG can still get car data while is charging ? .. which in case will be still time problematic for me to use the dog while the car is charging

 

[anko]

PS:
I guess with your adapters, only you can measure the SOC while the car is charging ... or ... maybe the DOG can still get car data while is charging ? .. which in case will be still time problematic for me to use the dog while the car is charging

Yes, I can monitor SoC and much more during the charging process. And so can the dog.

 

[elm70]

PS:
I guess with your adapters, only you can measure the SOC while the car is charging ... or ... maybe the DOG can still get car data while is charging ? .. which in case will be still time problematic for me to use the dog while the car is charging

Yes, I can monitor SoC and much more during the charging process. And so can the dog.

Interesting ... but my Bluetooth range is too short for check what is going on in my car while charging ... as well the charging in the early morning does not help

I'm not even sure if my ODBLink adapter is usable without entering in the car, since it has dummy security that if no device is connected for a while, and there is no sense of a car start in the last X minutes ... it does reject any connection ... often I need to unplug and replug, and sometime even click on its little button ... I should have took a wifi version of the OBD2 adapter ... but .. bluetooth was cheaper and initially the DOG did not support WiFi

 

[anko]

PS:
I guess with your adapters, only you can measure the SOC while the car is charging ... or ... maybe the DOG can still get car data while is charging ? .. which in case will be still time problematic for me to use the dog while the car is charging

Yes, I can monitor SoC and much more during the charging process. And so can the dog.

Interesting ... but my Bluetooth range is too short for check what is going on in my car while charging ... as well the charging in the early morning does not help

I'm not even sure if my ODBLink adapter is usable without entering in the car, since it has dummy security that if no device is connected for a while, and there is no sense of a car start in the last X minutes ... it does reject any connection ... often I need to unplug and replug, and sometime even click on its little button ... I should have took a wifi version of the OBD2 adapter ... but .. bluetooth was cheaper and initially the DOG did not support WiFi

Well, I have some issues there as well with my OBDLink MX WiFi adapters. I have three of them running side by side. They are only powered up when the car comes to live, essentially they are always 'under power' when the BMU is (initiating charging or preheating is enough). Yet, one or more may fall asleep after some time. Seems related to power save settings in the devices. But they are all configured the same.

Sometimes just unlocking the car (not even need to open a door) is enough to wake them up. As soon as I lock the car they fall asleep again. Not sure what is going on there.

 

[anko]

Last night, finished charging with 99,48%.
This morning, only 97,90% was still there.
Restarted charge and ended up with 98,49%.

 

[elm70]

Last night, finished charging with 99,48%.
This morning, only 97,90% was still there.
Restarted charge and ended up with 98,49%.

Was always the charging process completed when highest voltage per cell was 4.10v ?

In case ... it is maybe due to some unbalance

Else ... the BMU intentionally avoid to charge up to 4.10v the battery ... which is very "strange" ... or maybe it is one of their way to protect the car which may be left connected to a charger for "days"

All my lithium charger I had in these years for charge and balance my RC model batteries ... all have a charging process which end when voltage per cell is equal to maximum (4.2v or 4.1v), and charging current is below a minimum value.

The full charging process is : charge at constant current until max voltage is reach ... then charging at constant voltage until charging current is too little ...

Balancing is all time active while battery is charging ... keeping it under 0.01v difference

The main difference is that nobody would leave a hobby battery connected to the charger for days or even hours after the charging process is finish ... while this could happen on a PHEV

PS: For sure the charging process of our PHEV is a bit difference, since the initial phase more then charge at constant current, it is a charge at constant power ...but .. it would be interesting to see and monitor the final phase of the charging process ... mainly how evolve the charging current based on the cell voltage