Sudden EV battery drain

[Cris Niro]

Long time problem. I have an OBD2 reader now. Connected the recorder after I had charged the car to 80% overnight.

1. I started the car and charge dropped from 80% to nearly 0% almost instantaneously.
2. I stopped and restarted, no change
3. I reconnected the car to charger, it returned to 80% in 12 minutes.
   1. This is impossible with a 1KW charge. I filmed the dash read out for the 12 minutes.
4. I started the car and the dash read that the car was now 100% charged.
   1. Again after 12 minutes at 1 KW, it is impossible to go from 0% to 100%
5. The charge read 100% the entire 42 mile trip to work.
   1. This can be seen in the OBD2 data under “State of Charge Display %”
   2. The “State of Charge BMS %” OBD2 data shows 80% the entire 42 mile trip.
6. The “State of Charge BMS %” and “State of Charge Display %” OBD2 data show this entire timeline
7. I do not know if it is related but “Cell Voltage 68” has problems. All the other cells seem uniform.

This was the worst example. The last couple of days have been a series of unexpected charge plunges. I have had to do emergency charges at EV-Go stations to make it back and forth from work. Last night my home charging system reported adding 13.64 kWh (55miles), yet when I stopped the night before the car was reporting nearly empty. This morning the car dash read 227 miles nearly the entire 42 mile trip.

The dealerships say no error code, no problem. I contacted Kia they say I need to work through the dealerships. I can't afford to throw away $30,000. What can I do?

 

[insightman]

The dealerships say no error code, no problem.

How much charge is indicated after 1 minute of 1KW charging? Is it less than after 12 minutes? Have you tried driving your Niro after the indicated charge level plummets to zero when you turn it on? I'm wondering how many laps around the block you could make on zero indicated charge and if you receive the expected low-charge warnings.

Without error codes, your best hope is to replicate the problem at the dealership(s). Do you have free flat-bed tow-truck coverage?

 

[James Bradley]

I had some different oddities than this but see some similarities, (see the other thread) I was getting the turtle mode issue more than anything else but I bet that it is related. My issue seems to have been caused by a bad communication harness between the battery and the car. I did not have any OBDII codes but I was clear with the service writer that there would be codes in the BMS module. I showed the data graphs from my OBD reader showing the voltage drops and all of my data to back up that they need to look at the car.

Maybe I was just lucky that my service advisor took me seriously?

BTW- my "bad" cell was 58 and would kick the car into turtle mode and Check EV System mode pretty regularly.

 

[Cris Niro]

How much charge is indicated after 1 minute of 1KW charging? Is it less than after 12 minutes? Have you tried driving your Niro after the indicated charge level plummets to zero when you turn it on? I'm wondering how many laps around the block you could make on zero indicated charge and if you receive the expected low-charge warnings.

The thing is that I have a 7K charger at home. Something knew the battery (Car? Charger?) was actually at 80% and reduced down the charger to 1K. I have a video of my console increasing from 4% charge to 80% in 12 minutes. The charge estimator said that should have taken about 7 hours and 40 minutes. The last 10% the charger reduces the flow to .6 kW. In the same video at end I turn off the Car and back on and the read out now says 100% and reads that way for the entire 42 mile trip to work. The read out in the console is confirmed by the OBD2 data.

Without error codes, your best hope is to replicate the problem at the dealership(s). Do you have free flat-bed tow-truck coverage?

I had some different oddities than this but see some similarities, (see the other thread) I was getting the turtle mode issue more than anything else but I bet that it is related. My issue seems to have been caused by a bad communication harness between the battery and the car. I did not have any OBDII codes but I was clear with the service writer that there would be codes in the BMS module. I showed the data graphs from my OBD reader showing the voltage drops and all of my data to back up that they need to look at the car.

Maybe I was just lucky that my service advisor took me seriously?

BTW- my "bad" cell was 58 and would kick the car into turtle mode and Check EV System mode pretty regularly.

At the end of last year KIA replaced the harness and the controller. I wondering if they just didn't install the harness correctly or the installed ICCU was faulty as well?? From what I have read the harness has been a leading cause of similar issues. I have had straight up turtle mode while driving a few times, but the problem is not as reliable as the charge plunge. I can reliably make the guess-o-meter fail, but getting the dealership to run through the sequence is difficult because of their work load. Every time I go to this dealership they are super packed with customers. The other KIA dealership I went to was less helpful. Not sure why they refuse to look at the graphs from the App or the video. The tech said he would send the exported OBD2 data to KIA and create a Tech case, but I am losing faith that he will follow through. May have to try yet another KIA dealership.


Thank you for responding, it's nice to know someone is listening, even if its not KIA.

 

[insightman]

Something knew the battery (Car? Charger?) was actually at 80% and reduced down the charger to 1K.

The car controls the EVSE. Your car appears to be confused.

 

[Keith Smith]

Bad BMS.

 

[Cris Niro]

My car entered the shop June 23rd, it is still there. They gave me a loaner, but how long can this go on? They are saying that Kia Tech line turned down the first data set they provided, but now they can't reproduce the error. I asked to allow me to drive it with their recorder and they said no. I offered my OBD2 data demonstrating the problem and they would not accept it. There are too many people with this problem to think that KIA does not know what the problem is and how to fix it.

 

[Keith Smith]

This is gonna be a problem for EV owners in general until we hit a much higher critical mass. This is a "bad" BMS. "Bad" because it is either A) Faulty itself, or B) Faulty because it cannot identify a bad cell / other component. This is getting better as we have more BEV systems out there, and there are small clusters of technical resources that are getting better with this stuff, but [un]fortunately in general the systems are very reliable so there are not a lot of odd failures that allow for identifying failure patterns. In smaller battery systems (phones, ups's etc) the cost of just swapping it out was lower than trying to figure it out. With a BEV the incentive is there cost wise, but we have limited data upon which to improve the systems.

Batteries can be flaky as well, and the labor cost of pulling a pack out/apart is pretty high, but there isn't really that much to it. It's a bus, a bms with some relays, some sense wiring, and some cells. I hope they get you squared away, good luck.

 

[James Bradley]

My car entered the shop June 23rd, it is still there. They gave me a loaner, but how long can this go on? They are saying that Kia Tech line turned down the first data set they provided, but now they can't reproduce the error. I asked to allow me to drive it with their recorder and they said no. I offered my OBD2 data demonstrating the problem and they would not accept it. There are too many people with this problem to think that KIA does not know what the problem is and how to fix it.

Sorry to hear that. My car was there for about 2 weeks before they diagnosed the bad harness (I think it was more likely KIA approving the repair than diagnosis) It took another week for the harness to be shipped in and repaired.

I know you said they replaced your harness already, probably the reason for more scrutiny as well. I know with mine it was totally random when it would fault and I drove it much longer than I probably should have trying to narrow down certain situations that would cause the fault. My car was a factory buyback and the main battery was replaced just prior to me buying it, so that probably pretty much eliminated that option from the start.

Kieth- I certainly hope this is the reason for the difficulties in repair. The alternatives for them dragging their feet is really bad...

It also seems that everything has to have a Tech Line case opened and consulted on, so the data set is from the worldwide car service, not just a car dealer or figuring it out on their own...