The Infamous BMS Update: Virtual Reality or Miraculous Healing?

[Cliff]

Kia had my 2016 Soul EV+ for 7 months for a "BMS update." Before taking it in for the update, the 5-year-old battery with 50k on it (it's the second battery, not original) was down to 70% state of health (SOH). When finally returned, it went into limp mode, idiot lights came on, and it would not charge over 80%. Per a letter from Kia, I returned it for another BMS update and battery replacement. Two months later I picked up the vehicle. The dealer only did the BMS update, not the required (under warranty) battery pack replacement' "Kia decided not to replace the battery"... against their own letter's instruction.

Per the dealer:, "Your battery's SOH is now 100%, and your range is 105+ miles!"

Apparently, my aging, worn battery has been miraculously healed! Or, the BMS update is manipulating the readings so Kia does not have to replace my battery before the warranty period expires (ODO is 92k).

Anyone else share my suspicions?

 

[IanL]

After a BMS update, the values for SOH and predicted range are set to original, and you have to do several cycles (maybe 4 to 6) of discharge and charge before they converge to representative values. Then, if the SOH is 70% or below, you can restate your demand for a replacement battery. If the dealer challenges that, refer him to the summary of KIA TSB PS 548.

 

[Nigel]

I had a similar experience when my first battery was failing; Took the car in to confirm SOH and got it back with 165km of range; First trip I took to my daughters house - about 30km - stripped off 90km of range!! My conclusion at the time was that the dealer did a BMS reset before checking the state of health - thus the "positive" diagnosis that the battery was 100% OK; Sounds like the BMS update does the same thing and resets the system so it "restored" your range. I'm betting that after a few trips the range will drop to where it was before the car went into the dealership.

On the bright side from my experience, a second trip to the dealer and asking them to check the SOH before resetting the BMS got me a 55% rating and a warranty replacement; That battery has been in service for three years and right now I'm just over 200km of real range at 100% charge; Had the BMS update and wiring harness change done some time after the replacement battery was installed under the recall following the cases of battery overheating; All went well with no issues.

 

[Cliff]

After a BMS update, the values for SOH and predicted range are set to original, and you have to do several cycles (maybe 4 to 6) of discharge and charge before they converge to representative values. Then, if the SOH is 70% or below, you can restate your demand for a replacement battery. If the dealer challenges that, refer him to the summary of KIA TSB PS 548.

Thank you! I'm on my 6th recycle, so far no change. Estimated range is still 10-15 miles more than when the vehicle was new. I will give it a few more cycles.
Do you know if there are independent shops who can assess SOH, or can only Kia do that? Is there a way I can check it myself?

 

[Cliff]

I had a similar experience when my first battery was failing; Took the car in to confirm SOH and got it back with 165km of range; First trip I took to my daughters house - about 30km - stripped off 90km of range!! My conclusion at the time was that the dealer did a BMS reset before checking the state of health - thus the "positive" diagnosis that the battery was 100% OK; Sounds like the BMS update does the same thing and resets the system so it "restored" your range. I'm betting that after a few trips the range will drop to where it was before the car went into the dealership.

On the bright side from my experience, a second trip to the dealer and asking them to check the SOH before resetting the BMS got me a 55% rating and a warranty replacement; That battery has been in service for three years and right now I'm just over 200km of real range at 100% charge; Had the BMS update and wiring harness change done some time after the replacement battery was installed under the recall following the cases of battery overheating; All went well with no issues.

Thanks for the info. Hope springs eternal.

 

[IanL]

Thank you! I'm on my 6th recycle, so far no change. Estimated range is still 10-15 miles more than when the vehicle was new. I will give it a few more cycles.
Do you know if there are independent shops who can assess SOH, or can only Kia do that? Is there a way I can check it myself?

Use the Android app SoulEV Spy and Konnwei KW902 OBD2 dongle. However, that uses BMS data as well.

The indicated increase in range may be due to the replacement battery, if the cells were updated to the new type, which have higher capacity. The battery capacity increase is from 27 kWh to 28.8 kWh. However, if it is really at 70% SOH, that would not explain it.

You can get a reasonable estimate of current capacity by recording before and after charge %ages, distance run and m/kWh (or km/kWh) from the trip meter. From that, you can get kWh used for percentage battery used, and scale that up to 100% for the actual capacity of your battery. Divide that by 27 or 28.8 as appropriate to the cells in your battery to get SOH. Average the answer over several runs for a better estimate, as the data from the car lacks precision.

 

[nileriver]

Thank you! I'm on my 6th recycle, so far no change. Estimated range is still 10-15 miles more than when the vehicle was new. I will give it a few more cycles.
Do you know if there are independent shops who can assess SOH, or can only Kia do that? Is there a way I can check it myself?

Have you taken a test drive to see what range you are actually able to achieve?

 

[Nigel]

You can check your battery health yourself using the EV-Spy app and an old Konnwei KW902 ELM-327 v1.5 Bluetooth v 4.0 OBDII adapter (Compatible with the older Kia and Hyundai EV's) into the OBDII port of the car.

There is an EV-Spy users guide at the following web address: https://evranger.com/en/soul-ev-spy-users-guide.html

 

[Cliff]

Use the Android app SoulEV Spy and Konnwei KW902 OBD2 dongle. However, that uses BMS data as well.

The indicated increase in range may be due to the replacement battery, if the cells were updated to the new type, which have higher capacity. The battery capacity increase is from 27 kWh to 28.8 kWh. However, if it is really at 70% SOH, that would not explain it.

You can get a reasonable estimate of current capacity by recording before and after charge %ages, distance run and m/kWh (or km/kWh) from the trip meter. From that, you can get kWh used for percentage battery used, and scale that up to 100% for the actual capacity of your battery. Divide that by 27 or 28.8 as appropriate to the cells in your battery to get SOH. Average the answer over several runs for a better estimate, as the data from the car lacks precision.

Thank you so much - great info. I will try the calculations. However, my battery was not replaced (well, it was 4.5 years ago). It was SUPPOSED to be replaced in March, per letter from Kia, but now they're refusing. Hence my concern about how my battery's post-BMS update SOH and capacity, even though a few years old, is performing better than when new. And better than the original battery when new.

 

[IanL]

I had the BMS software update applied yesterday (Recall 231118). Mine is the 30 kWh battery and it did not need the harness change. Of course, I don't know which version I received, but I expect it is the corrected version, as it only became available to my car in the last month or so.

The main thing is that there is no apparent change to anything - the GOM values are as before, and my 100% range is currently 126 miles (so far, our summer has been cool, and it will probably be in the 140s when (if) things improve). So the GOM was not reset.

 

[IanL]

....There is an EV-Spy users guide at the following web address: https://evranger.com/en/soul-ev-spy-users-guide.html

Note that the User Guide FAQ is out-of-date as regards display of SOH for the 30 kWh battery - it no longer displays "Unknown Deterioration". It now displays the SOH value calculated by the BMS - the value does not exceed 100%, even if the true value is greater, i.e. the buffer has not been exhausted.

 

[IanL]

Further to the above, I have now found that Spy is telling me the BMS has not yet been able to calculate the battery SOH, so the software update has wiped some historic parameters, and the "Unknown Deterioration" has returned, pending sufficient cycling of the battery to restore SOH reporting.

 

[IanL]

Further to the above, I have driven the battery down to 17%, recharged to 100%, and Spy now reports SOH 100%, which is what it used to say before the BMS update. The GOM shows 134 miles.

So far, so good.