Battery replacement woes

Kia Soul EV Forum

Help Support Kia Soul EV Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


New member
Apr 26, 2021
Hello, I'm new to the fourms! I've browsed through the forums a bit (great resource!) but I was hoping for a bit of feedback and possibly suggestions regarding my current battery capacity situation.

First a bit of background. I purchased my 2016 Soul EV+ in 2019 as a daily commuter. It was originally a lease vehicle with about 37,000 miles. COVID happened and my work role shifted to 100% remote, so in the 1.5 years I've owned the car I've only put about 2,500 miles on it. I live in Colorado where it gets quite cold, so I keep the Soul parked in the garage (heated to about 60F) during the winter months and when 4x4 is required (we get a lot of snow up here as well).

When I purchased the Soul it had an estimated range of 83 miles. Since owning it, the estimated range has dropped by over 10 miles, to around 68-72 miles at full charge. This is with all climate features off in >60F weather - the range is even shorter when using the heat/AC or driving in cold weather, which is to be expected. I average about 3.6 mi/kWh, and primarily drive at lower speeds (30-45mph) on back roads.

Disappointed with the range, I took the vehicle to the nearest dealership (about 40 miles one way). They reviewed the estimated range and initially agreed with me - it's likely your battery needs to be replaced. They're quite familiar with the Soul EV platform, based on reviews and feedback I've received from another friend with a 2016 Soul EV. The dealership applied two recalls (SA427 and SC191) which took several weeks. After completing these recalls, the dealership called me back and explained the vehicle battery showed 93% SOH and that everything was functioning as intended, despite my experience to the contrary. They seemed very confused about this. I tried contacting Kia, who would not release any sort of quantifiable data, just "SOH is 93%". There were also a number of condescending comments regarding my driving habits, inability to read a thermometer/odometer, and general lack of understanding regarding how batteries work, which was disappointing. I should also note the dealer won't even make me an offer on the vehicle - they clearly recognize there's a problem, although they won't acknowledge that directly.

When I returned to pick up the vehicle, it was charged to 80% and the range estimate was a whopping (and impossible) 105 miles. On a full charge, it shows 122 miles of available range! After driving 22.7 miles at an average speed of 43mph on a flat road, the range estimate was down to about 65 miles and battery capacity was at 45%. This behaviour is reproducible on shorter drives as well - for every mile on the odometer, I lose about 1.6 miles of estimated range.

I've also run a few tests to try measuring actual power consumption. I'm a bit limited here, but I do have access to an ANSI C12.20 energy meter. So far the weather has been less than cooperative (we're still in our cold season) but I've tried two charge cycles on days with temperatures above 60F, one on a CHAdeMO station (since I don't know the efficiency rate of the AC/DC charging) and one on my 240Vac 26A outlet at home. I'll try to attach my findings as a separate PDF. Both tests show a remaining battery capacity of about 21.5kWh remaining. I do have a KONNWEI KW902 OBDII dongle on order so I can hopefully view SOH myself.

If you're still with me after all that, here's what I think is going on:

1. The dealership applied recall SA427 (a firmware update to the BMS) before testing battery SOH
2. On testing SOH, the value returned was incorrect, because the BMS was updated and wasn't recalibrated
3. Kia is using this as justification to deny my warranty claim
4. The BMS update also skewed the estimated range readings (unintentionally, of course)

I'd appreciate any suggestions here. My plan over the next few weeks (if the weather cooperates) is to run the vehicle down below 20% and charge up above 90% at least five times (as recommended elsewhere in the forums) in an attempt to recalibrate the SOH reading. I'm also going to try the Soul EV Lite app with the KW902 dongle to see if I can read SOH myself. I'd welcome feedback regarding my testing methodology, which is admittedly a bit crude (I'm working with percentages reported through the Soul dashboard and an assumed linear AC/DC conversion efficiency of 90%, which is very generous). If I'm missing something obvious I'd love to know.

Thanks in advance!
If you want the quickest way to do this:

Check that the outside temp is above 10C and will be for awhile (like a day or two)
Check that your battery pack is also above 10C (OBD2 reader & Torque or SoulSpy needed)
Charge to 100%
Discharge to 10% (no charging in between)
Charge to 100% (no interruptions!)

Calibration should have occurred and hopefully you can put that dealership & Kia to shame. The dealership might be clueless, but Kia corporate knows exactly what's going on here - so shame on them, and I look forward to hearing about your battery replacement.
Your car has a 27kWh battery not 30kWh.
From the data you give from your tests that would be SOH = 80%.
You will not get a replacement battery until SOH goes below 70%.

It is more common than not that the Kia dealers reset the battery computer to give you a false reading.
They have no idea that they are doing it wrong.

Kia however must know.
Thank you very much for the replies! Glad to see I'm not totally off base here.

EVDee, if I'm understanding correctly I only need to run that cycle once? I believe I saw some other folks saying it needed to be run several times to ensure an accurate calibration. I hear you regarding the temperature - the weather out here has been uncooperative, but we're nearly to the point where the daytime temperatures will remain above 10C/50F for the whole day and I can park the car in my heated garage overnight. I do have a OBDII dongle on the way and I've already got SoulSpy installed!

JejuSoul, great information regarding the battery. I think I was using the nominal vs actual capacity, my mistake. That's a major hole in my calculations for sure, but I'm still working with imperfect data here:

1. I don't know if energy usage is linear in regards to battery percentage (SOC). So, for example, let's say it takes 9kWh to charge from 0-33%, but 10kWh to charge from 33-66% and 8kWh to charge from 66-100% - my calculations don't account for that.

2. I *do* know my AC usage calculation is incorrect to some degree, because I'm totally guessing on the AC/DC conversion efficiency and there's no way that's a linear relationship (might be 90% between 50-85% SOC, and 85% at 85-95% SOC, and 80% at 95-100% SOC).

I'm also limited to only one data point per test, which isn't great. I'm hoping to run some more road tests once the weather warms up a bit more (for example, drive 50 miles on a (relatively) flat road at 40mph from a full charge and see where my SOC is after that). Any thoughts on the accuracy of the SOC values provided by the vehicle (eg, on the dashboard)? Is 50% really 50%, or is that dependent on accurate calibration as well?

While I'm on the subject of testing, does anyone have a good suggestion for intentionally draining the battery for testing? We're out in the mountains, and while I do have AAA (free towing) it would take several hours for a tow truck to arrive if I screw up and completely drain the battery out on a back road somewhere. I thought about just parking the car outside, opening all the windows, and setting the heater to max - but maybe there's an faster/better way?

Thanks again!
Just wanted to provide an update.

I received my KONNWEI KW902 adapter, and it's working well with Soul Spy Lite. I plan to pick up a Play Store recharge card so I can buy the full version next time I'm in town.

Soul Spy Lite showed a SOH of 111% before attempting the recalibration cycle.

I ran the car from 100% SOC to 8% SOC (that was scary), then charged back to 100% on a 240Vac receptacle in my garage without a break. Vehicle/battery temperature was above 10C/50F the entire time (right around 18C/65F the whole day, actually). Charging used 22.64 kWh of AC energy, so based on the correction earlier in this thread:

estimated 24.06 kWh required for a full (0-100%) charge
given an AC/DC conversion efficiency of 90% (which I still feel is too generous): 22.15 kWh of DC energy delivered to battery
this works out to about 82% of remaining capacity

That being said, I'm not certain I managed to recalibrate successfully. My estimated range is now back where it was before I took the vehicle in for service (around 71 miles/114km) and my efficiency is now reported at 3.5 mi/kWh or 5.6 km/kWh (I did engage in some aggressive driving in an attempt to drain the battery a bit quicker). However, Soul Spy Lite now reports the SOH as 111.5% (a .5% increase). Is this expected, or have I made a mistake in the process somewhere?

Of course, today it's back below freezing and we've got 4" of snow on the ground, so no more testing for awhile.

Thanks again!
This is an old post now but FYI the SA427 update probably disabled your heat pump, decreasing winter range substantially.
bovinezro said:
..... However, Soul Spy Lite now reports the SOH as 111.5% (a .5% increase). Is this expected, or have I made a mistake in the process somewhere?

Soul Spy Lite has not been updated for a long time, and it may be that the SOH calculation has not received the corrected code which is in the paid-for version.