[djsoftware]

I’m convinced my BMS is taken from my old Leaf 30, in just over a week the SOH has gone from 89.8 to 91.1 and today it’s 90.7. I’ve run the car low and then charged up to 100% with little effect, Has anyone else had this behaviour as it’s just like my old Leaf 30 which varied all the time but I was always expecting my Ioniq on just 20k miles to have an SOH of 100% like everyone else. Oddly I don’t think the range is affected. I’ve also tried a few apps which have all given the same reading.

 

[HandyAndy]

You've had a lot of issues, your thread here https://www.ioniqforum.com/threads/turtle-mode-when-batter y-20-on-ioniq-38-and-soh.44723/ where you seem to have some rather large voltage differences between cells. If the dealer can't detect this same cell imbalance, then I don't know what you can do next.

 

[djsoftware]

Yes Andy - problem is I don’t get any cell imbalance apart from when it goes into turtle when going up the steep hill on the a38 and only for about 20 seconds, problem is the dealer could not repeat it so I’m trying to work out how to constantly repeat but at any other time the cells are all perfectly balanced.

 

[HandyAndy]

Can you get the OBDII dongle & EvWatchdog or other app to display a continuous reading of the cell voltages as you drive? Then arrange a camera-tripod, clamps, whatever so another device films it running, or maybe there's a phone app that can capture the phone's & make an mp2 of it? I have an old-but-good digital camcorder, samsung 2016 vintage, something like that which can do time-delay captures would be ideal, grab 1 shot a minute/whatever.

Then armed with the video evidence, I'd send it straight to the battery swap team on Hyundai helpline 0800 981 981, bypass the dealers & get this to the techs. And you really want to film the car's dash at the same time to see speed/distance, as well as central console showing energy info, as much ammo as poss.

 

[Superhero]

Are the 38 supposed to have 100% SOH all time just as the 28?

 

[djsoftware]

Can you get the OBDII dongle & EvWatchdog or other app to display a continuous reading of the cell voltages as you drive? Then arrange a camera-tripod, clamps, whatever so another device films it running, or maybe there's a phone app that can capture the phone's & make an mp2 of it? I have an old-but-good digital camcorder, samsung 2016 vintage, something like that which can do time-delay captures would be ideal, grab 1 shot a minute/whatever.

Then armed with the video evidence, I'd send it straight to the battery swap team on Hyundai helpline 0800 981 981, bypass the dealers & get this to the techs. And you really want to film the car's dash at the same time to see speed/distance, as well as central console showing energy info, as much ammo as poss.

Thanks Andy - yes tried this last week whilst I had my son in the car so he could film it but as luck would have it power was restricted but turtle mode did not kick in. I do wonder if this is ambient outside temperature related as it was milder last week but trying again later, but is about 8 degrees so that will test the theory.

 

[djsoftware]

Thanks Andy - yes tried this last week whilst I had my son in the car so he could film it but as luck would have it power was restricted but turtle mode did not kick in. I do wonder if this is ambient outside temperature related as it was milder last week but trying again later, but is about 8 degrees so that will test the theory.

Interestingly I tried again tonight and same as last week no turtle but with my foot fully down the car started limiting the power to about half way on the power scale so obviously trying to protect the battery.

 

[vanctour]

@djsoftware, is there any sort of error message when this happens? I also wonder if putting it in sport mode would allow you to get over the hill without this happening. And also, do you have traction control on? Maybe disabling it would allow for the motor not to kick out. I know that when in cooler temp, when the motor on an EV is pushed, it cuts power when it feels the slightest slip, but it usually kicks back in immediately. I wonder if the sensors are detecting a slip and cutting power? Try the run without Traction control on and also try it in Sport mode. Interesting to see the results.
Also, did you ever get the coolant warning? and receive the proper flush and replacement fluid. Maybe the excess heat isn't being carried away with the cooling system properly and it is lending to this power kickdown.
Just trying to eliminate the variables to help solve your issue.

 

[djsoftware]

Thanks for those ideas @vanctour I will definitely try those as its been a hard one to isolate. Apart from when I got the turtle mode coming up and the reduction of power no other messages came up, no errors are logged on the car as once I hit the top it all goes back to normal. Obviously I do have the logging which showed the great voltage difference between cells but that is brief and at all other times the cells are balanced. Interestingly I did a full 100% charge last night and State of Charge [BMS] was 96.5%, [BMS] State of Charge Display was 100% which looks quite normal even though the [BMS] State of Health was 90.7%.

I've never had the coolant warning and slightly reluctant to book it in so that will probably be done when its due its third service in August don't really want it messed about with if there has not been an issue.

 

[Mikael48]

Try to record this sensor in Car Scanner: Battery Cell Voltage Deviation V

(not need to display all cells)

 

[Fu Kin Fast]

I had similar situation with my 21 Ioniq after a half year. It showed something like 91% SoH (though all cells were balanced). After bringing it to the dealer they upgraded the BMS and now it shows 100% SoH (maybe it is hardcoded?).