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Re: Battery Ageing Model

Posted: Mon Jan 20, 2020 5:11 am
by Zattaxu
JejuSoul wrote:
Zattaxu wrote:...There have been reports of failing battery packs also in Norway. As some owners has had their cars 5 years (first cars were delivered autumn 2014) many owners has reached 100.000 km (appx 60.000 miles) or more. I don't know the percentage which have claimed replacement, (Norw. warranty: 70 % capacity after 150.000 km/7 years), but my impression from Norw. EV forums/Facebook groups is that a lot of owners of the cars which have passed 100.000 km are experiencing degradation problems. Some have had their battery packs replaced after waiting up to 6 months on a new pack...

Thanks for posting Zattaxu. This is the first battery replacement story from Norway I have seen.
I have just read your post on - Mistet kapasitet på fremdriftsbatteri - erfaringer?

I still think that as a percentage the failure rate in Norway will be much lower than elsewhere. At present almost 42% of all Soul EVs ever produced are in Norway. Clearly some of those cars are now failing. But I assume many are not.
I base this assumption on the N issan L eaf, which has a high failure rate in the USA and a low failure rate in Norway.
Am hoping the Soul EV doesn't turn out to be worse than the L eaf.
If it is, then it means we have been looking in the wrong direction 'high temperatures' as the cause of most battery failures. Instead it may be 'battery stress' caused by long and fast journeys that are the primary cause.

I took the liberty of translating some answers to a facebok post on the Norwegian Kia Soul EV forum. The question was: How many has driven the car more than 100 000 km, what SOH do you have, and what does the GOM say.

I guess that most people are refering to the SOH from what the dealer reported last time they had their service (normally: every 15.000 km in Norway), but 11 people replied (as I mentioned before, others to have reported their batteries degrading more now, than before).

1: Mileage: 115000 km. 84 % SOH, GOM says about 114 km.
2: Mileage: 180000 km. Got new battery at 120000 km.
3: I'm just under 110,000 on my 2016. Can't remember what it said on the battery part, but the SOH was in the 90s somewhere.
4: Milage: 125k. Battery 80%. GOM says 102 km fully charged.
5: Milage: 130k. Battery degrading fast. Should get it checked but think it is approaching 70%. GOM says 70 km on full charge.
6: Milage: 117k measured it at 90k. Was 93% - guess it has dropped 7%. About 100+ km on GOM.
7: Mileage: 105 000km. SOH last reports of 94%, 90%, 100%, 86 % and on last service 92%. Don't trust the SOH dealings from your reader. GOM at about 120km.
8: I got my battery replaced on warranty at 120,000 km. Was then under 70%
9: Mileage: 135k run, 75% SOH, shows about 90 km fully charged.
10: Approximately 120,000 km and 83 % SOH. Gets 90 km fully charged.
11: If this is true I will get a new battery soon. Has driven 116,000 and can run 94 on full tank.

My mileage is 122 000 km (first time registered Nov 2014) and SOH is at 69.3%.

Re: Battery Ageing Model

Posted: Fri Mar 20, 2020 6:07 am
by ZuinigeRijder
ZuinigeRijder wrote:My Kia Soul EV from September 2014 has now driven 108251km and the SOH is now 93.55%. Note that the previous owner already got a SOH of approx. 102% after the first year.

Seems that it pays off to mainly charge till 80% SOC (yes, my model has still the option to charge till 80%) and try to keep it above 30%. I also do not drive fast, mostly 90 km/h on highway. My average speed is 57 km/h in the board computer. Also try to park/charge in the shadow. My car has now also the possibility to fastcharge to 91% instead of 86%, but I never used it, because fast charging above 80% takes more time (because it will not charge with 50 kW). I do not use fast charging often.

These are the latest readings of TorquePro, after a charge from 13% till 100% with the home charger:

Here an update after 127544 km on the ODO meter for my Kia Soul EV from September 2014 . The minimum deterioration is 15.9 and maximum deterioration is 18.3, giving an average of 17.1. The State Of Health (SOH) is according to the Torque calculation 92.9%. The Cumulative Energy Discharged (CED) value is 22306. This means that calculating with 27 kWh battery I have used 826 charge cycles.


Still going strong.

Re: Battery Ageing Model

Posted: Wed Mar 25, 2020 7:38 am
by JejuSoul
ZuinigeRijder wrote:...Still going strong...

Yes. That is strong.
You will be over the 150,000km warranty limit in less than 12 months time. And very unlikely to get a replacement battery by then.
If degradation continues in a linear fashion your car will not reach 70% degradation until 300,000km.
Other cars have shown the degradation line falling off a cliff. How or why that happens is currently unknown.
That decline has not been seen in any of the cars we have been testing from the start.

My blue car. A 2015 Soul EV has 69,250km and an SOH of about 94%.
It's good but not as strong as yours. I also drive carefully and only charge to 80%. Am guessing it;s because I have much hotter summer weather than you. I still have many years before the warranty runs out, and I expect a couple more hot summers will knock my degradation curve below the red warranty line. This replacement battery lottery is far from ideal. Owners who look after their car for many years will 'win' or 'lose' this game based on an external factor, the climate.