Soul EV Spy Questions and Answers

[edzee3]

I have a 2015 Soul-EV (bought new) with 27,000 miles. Soul EV Spy App shows Battery SOH = 73.3% with SOC = 82 %.
And, after using much of the energy, also shows SOH=65.3 % with a SOC = 20 %.

Why would the SOH change with change in SOC ?

What is the way to get the "true SOH " ?

Thanks

 

[JeroenE]

What is the way to get the "true SOH " ?

Go to the dealership and ask them to create a report about the health of the battery. Don't let them reset the BMS first! That means it will take some time before the BMS will learn the actual value of the SOH.

Let them read this before they do anything: https://www.tsbsearch.com/Kia/PS548

 

[IanL]

I have a 2015 Soul-EV (bought new) with 27,000 miles. Soul EV Spy App shows Battery SOH = 73.3% with SOC = 82 %.
And, after using much of the energy, also shows SOH=65.3 % with a SOC = 20 %.

Why would the SOH change with change in SOC ?

I believe the KIA procedure is to take the SOH reading when the battery is 100% charged. Perhaps the BMS cannot provide an accurate value under partial charge?

 

[JejuSoul]

I believe the KIA procedure is to take the SOH reading when the battery is 100% charged.

No. Not true. Kia measures the BMS at whatever SOC the battery happens to be at.

Edzee - the only measure of the BMS that decides whether you get a replacement battery or not is the one that Kia reads.
Do not fret about whatever your app reads, just take the car to Kia and get it checked.
Do tell them to read the SOH before doing any updates, otherwise the BMS computer will be reset to 100%, and they will tell you your battery is fine.

When I got my battery replaced I took it to KIa on the day the SOH showed 69.5%. Kia's diagnostic agreed. I kept driving the old battery for another 3 months. It never went below 75% SOH during that time. It didn't make any difference that the SOH fluctuates. Once you get the green light from Kia you know you will get a replacement.

 

[edzee3]

JejuSoul,
Thanks for your useful reply but that still leaves me uncertain as to how the SOH varies with the SOC.
Seems that your SOH did vary above 70% for several months after you got the KIA dealer SOH reading at less than 70%.

Maybe it's best to get the KIA dealer to measure the SOH with a low or average SOC ?

Ed Z
California

 

[JejuSoul]

-
Edzee - There is no relationship between the SOH and the SOC.
Sometimes the SOH is stable for months other times it fluctuates up and down +/- 5%.
Sometimes after driving fast, after a hot day, after a series of quick charges, after a battery calibration ...
It is not useful to worry about these, It is not predictable.
What is stable is the linear decline if you plot multiple readings over many seasons.
Until it isn't. At some point that linear decline ends and the battery falls off a cliff.
The point at which it does is also not predictable.

The simplest way to know when your battery is at 70% or less is if the range is now 70% or less than when you bought the car.
( Driving the same route, at the same speed, in the same weather conditions.)

 

[edzee3]

jejuSoul,
I finally understand your good description of how I can deal with the SOH of these batteries.
My car is not used as a regular commuter car. And for just short trips.
I have just started recording the SOH using "Spy" and will plot it out over time and the various trip info.
At some point, I'll have the dealer do the official SOH.
Will post what I find. Thanks for the help.

 

[Lithium]

jejuSoul,
I finally understand your good description of how I can deal with the SOH of these batteries.
My car is not used as a regular commuter car. And for just short trips.
I have just started recording the SOH using "Spy" and will plot it out over time and the various trip info.
At some point, I'll have the dealer do the official SOH.
Will post what I find. Thanks for the help.

if you really are below 70% then you get a new battery. 2015 had 10 yr 100k mi warranty and you are looking at accelerated degradation. 70% or great at 10 years or 100K miles. whichever comes first.