Analysis of a replacement battery.

[IanL]

[JejuSoul]

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It is now 2 years since I had the battery replaced on my white 27kWh 2015 Soul EV.
On December 30th 2019 the car had driven 86,993km before getting a new battery.
On December 30th 2021 the odometer reads 116,590km. That's 29,597km on the new battery.

Here's the latest Torque reading



Clearly the new BMS does not show the same deterioration data as the original.
The original BMS began showing the deterioration from the start as capacity was lost from the early years' buffer.
The new BMS does not do this. Maybe it will only show deterioration after the early years' buffer has been entirely lost.
Maybe another 2 years before I have a real deterioration reading on this car.
At the last service a few months ago the SOH was 100% as expected.

My blue 27kWh 2015 Soul EV is now 6 1/2 years old and has driven 88,554 km.
This car has the original battery and the original BMS.
Back in 2017 I have the readings for that car after 29,769km.
CEC 6185.5kWh, CED 6011.8kWh
Max Det 8.5, Min Det 1.1

[MassDeduction]

-
It is now 2 years since I had the battery replaced on my white 27kWh 2015 Soul EV.
On December 30th 2019 the car had driven 86,993km before getting a new battery.
On December 30th 2021 the odometer reads 116,590km. That's 29,597km on the new battery.

Here's the latest Torque reading



Clearly the new BMS does not show the same deterioration data as the original.
The original BMS began showing the deterioration from the start as capacity was lost from the early years' buffer.
The new BMS does not do this. Maybe it will only show deterioration after the early years' buffer has been entirely lost.
Maybe another 2 years before I have a real deterioration reading on this car.
At the last service a few months ago the SOH was 100% as expected.

My blue 27kWh 2015 Soul EV is now 6 1/2 years old and has driven 88,554 km.
This car has the original battery and the original BMS.
Back in 2017 I have the readings for that car after 29,769km.
CEC 6185.5kWh, CED 6011.8kWh
Max Det 8.5, Min Det 1.1

Congrats, looks like you're getting good results on both cars now. Good to see you post again, for the first time in a while JejuSoul!

[ksoul2084]

Those are some truly impressive numbers.

FYI. My battery was replaced (well, the cell packs were swapped out) last August. Since then I've only put on approx. 6,000km of mileage, usually charging using Type 1 to 80% max.

Last night I did an uninterrupted charge from 7% to 100% to reset the SOH, and let the car balance the cells, etc.

Once completed the car reported all cells at 41.6v, outside temperature was about 11c. Battery SOH is 99.7%, though estimate range was only 120km (lower efficiency with cooler temps and heaters running, etc. I guess).

I have a fairly disturbing update on my 2016 Soul EV+. Battery cells were swapped in Aug. 2020, I had posted the last update above in May of 2021. I have noticed the estimated range has dropped continually over this summer and fall, but hadn't checked with SoulSpy until today.

Jan 4th, 2022
Mileage: 167731.9km (so approx. 11,000km since replacement)
SOH: 91.9%
battery.min_cell_deterioration_pct: 16.3
battery.max_cell_deterioration_pct: 18.3

I almost always charge to 80% using Level 1 120v charging at home. I have charged to 100% using Level 1 about 4 or five times that I can recall in the last year.

This is very disappointing to me, to have my replacement cells with this high a deterioration with so little mileage and lack of abuse on my part.

Any chance it just needs to be top-balanced aggressively?

[IanL]

What is the spread of cell-pair voltages?

[ksoul2084]

What is the spread of cell-pair voltages?

Here is a sampling of cell voltages taken today, the first two when the car was started after 30mins scheduled preheat cycle (it is -43c with windchill outside here today, approx. -8c in the garage), and the next two after running a few errands around town, maybe 5km driving at slow speeds.

[IanL]

When I got my 30kWh model at 2 years old and 31,000 miles, I didn't know about Spy, but I calculated SOH based on dashboard data and charging records. If my method is valid, the SOH was 94% and the winter range (winters are mild here) was 112. I did eight charges (using the 10A plug-in charger) to 100%, because I didn't know any better. Then I started a 30% to 80% regime. By the next winter, the SOH was 102% and the range improved to 120 miles. At that point, the cell-pair voltages were pretty even, with about eight at 0.02V below the others.

I carried on with 100% charges every 4 recharges or so, till I saw that all cells read the same, and I then stopped the balancing charges and haven't done any for 8 months. The cells have remained balanced. At 39,000 miles, the SOH averages about 102.5% and the winter range about 120 miles. During that time, I fitted a wall box charger which can do 32A, but I usually use 16A, because what's the hurry?

My home-grown SOH method may not be valid (Spy just reports 100% by readout from the BMS, not max & min det), but there's some evidence that a measure of recovery is possible.

[MassDeduction]

When I got my 30kWh model at 2 years old and 31,000 miles, I didn't know about Spy, but I calculated SOH based on dashboard data and charging records. If my method is valid, the SOH was 94% and the winter range (winters are mild here) was 112. I did eight charges (using the 10A plug-in charger) to 100%, because I didn't know any better. Then I started a 30% to 80% regime. By the next winter, the SOH was 102% and the range improved to 120 miles. At that point, the cell-pair voltages were pretty even, with about eight at 0.02V below the others.

I carried on with 100% charges every 4 recharges or so, till I saw that all cells read the same, and I then stopped the balancing charges and haven't done any for 8 months. The cells have remained balanced. At 39,000 miles, the SOH averages about 102.5% and the winter range about 120 miles. During that time, I fitted a wall box charger which can do 32A, but I usually use 16A, because what's the hurry?

My home-grown SOH method may not be valid (Spy just reports 100% by readout from the BMS, not max & min det), but there's some evidence that a measure of recovery is possible.

Good call. Charging that car at 32 amp would exceed the ideal charging speed. IIRC correctly, that battery pack is 2 modules of 40 Ah useable, so the full pack is 80 Ah. With the ideal charging amperage being 25% of the Ah rating, that means 20 amp is the maximum ideal charging speed for the 30 kWh pack. For the 27 kWh pack, the ideal maximum charging rate is 18.75 Ah. So yeah, if you're not in a hurry, don't exceed those numbers!

I try to store at a medium-ish state of charge, and then wait until the last convenient moment to charge it any higher. I do that with everything I own with a lithium ion battery (cell phone, e-reader, e-bike, e-car, you name it). I definitely do not plug my phone in and leave it on the charger all night anymore! In fact, my phone is never plugged in at night. And I don't fast charge it when there isn't a need, either.

Though this does mean, having never drained the Soul EV below 18%, nor ever charged it to 100% in all the time we've owned it, we have NO idea what the SOH is. But Soul Spy reports that the cells are still nicely in balance, so there's likely no need. If they ever get enough out of balance to require a conditioning charge, then we'll make sure to drop below 18% first so that we also get an SOH reading.

[IanL]

...Though this does mean, having never drained the Soul EV below 18%, nor ever charged it to 100% in all the time we've owned it, we have NO idea what the SOH is. But Soul Spy reports that the cells are still nicely in balance, so there's likely no need. If they ever get enough out of balance to require a conditioning charge, then we'll make sure to drop below 18% first so that we also get an SOH reading.

If you would like to try my calculation method, which does not require you to charge to 100%, it is here.

[MassDeduction]

...Though this does mean, having never drained the Soul EV below 18%, nor ever charged it to 100% in all the time we've owned it, we have NO idea what the SOH is. But Soul Spy reports that the cells are still nicely in balance, so there's likely no need. If they ever get enough out of balance to require a conditioning charge, then we'll make sure to drop below 18% first so that we also get an SOH reading.

If you would like to try my calculation method, which does not require you to charge to 100%, it is here.

Yeah, I remember reading that earlier. Thank you for reminding me about it! I expect your method would provide a pretty good guesstimate, for sure.