Hyundai IONIQ Forum banner

121 - 126 of 126 Posts

·
Moderator
IONIQ Electric, SE (w/ CCP) 2018.
Joined
·
746 Posts
Fanda

Not total sure I understand your method. Not saying it's wrong because like I said, I don't fully understand your method. But the fact that you mention 20% as significant, is part of why I think your method may be flawed.

I've been able to observe (using EVNotify) that the SoC displayed and the SoC BMS (Real SoC) are never the same. SoC displayed is higher by about 5% at the top end and about 3% lower at the bottom - this is well known for the IONIQ 28 kWh BEV. The cross over is at about 22% SoC. This is the buffer that Hyundai has built into the IONIQ and why our batteries appear to last so long. (They don't ever get fully charged and the BMS also starts using the buffer once it detects any degradation, so your range doesn't drop until you have at least 8% degradation).

AFAIK, the easiest and best way for a layman to determine degradation is to charge to 100% and drive the car as low as you can and record the total energy expended - Torque Pro, EVNotify, etc, you can then proportion this value to calculate the theoretical energy available if you expended 100% of the charge. Then after some time (6 months or a year) perform the test again. If there has been any degradation, then the energy the battery can release will be less.

Regards

OB
 
  • Like
Reactions: KevinT

·
Registered
Joined
·
7 Posts
OB, actually that is exactly what I did. Except that the CED/CEC parameters were recorded several times, and not just with 100% and 0%. Doing so, in addition to the overall degradation (which is a summ of the spent energy/28) also gave the idea of non-linearity of the SoC% curve, in relation to the energy taken from the battery. I purposely used the display SoC and not BMS SoC since display SoC must represent the official 28kWh figure.

PS: I know some people think Ioniq reduces the buffer in order to complensate for the degradation, but I doubt this is the case with this car, as when one charges to 100% display, the BMS will be at 95%. And discharging to 0% will give 2.5% BMS which was the same when the car was new
 

·
Registered
Joined
·
110 Posts
PS: I know many people think the Ioniq realBMS, which is at 95% when the SOC is at 100%, and discharging to 0% will give a realBMS of 2.5% reflects the total capacity or buffer size but I doubt this is the case with this car, because these values remain the same even after degradation
 

·
Super Moderator
Joined
·
1,594 Posts
Interesting analyses of factors affecting degradation can be found here.
(based on data from 6000 cars)
 

·
Registered
Joined
·
248 Posts
PS: I know many people think the Ioniq realBMS, which is at 95% when the SOC is at 100%, and discharging to 0% will give a realBMS of 2.5% reflects the total capacity or buffer size but I doubt this is the case with this car, because these values remain the same even after degradation
Does this mean that the value of the Torque PID "SOH" will always remain at 100%, even after serious degradation?
 
121 - 126 of 126 Posts
Top