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Discussion Starter #1
Hello,
I own the skoda Citigo e iv (32kWh) that can charge at around 35 kW from 0 to 30% and then drops drastically afterwards. See graph here Ladetest Skoda CITIGOe iV
The manual says this type of charge should be avoided due to the permanent loss in capacity.
I was wondering if for this car is really that important compared to the type 2 charging (7kW and below) in terms of battery wear.
Do lithium batteries in general really suffer from close to 1C charing for just a short amount of time?
 

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ONTO/Evezy £50 Code: CADA7
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It's still going to produce more heat and stress on the battery than slowly charging on AC. The wear isn't going to be as bad as some other EVs, but you should still try to AC charge as much as possible, leaving DC Rapid charges only for when you really need them on longer journeys.

If you're not constantly doing it then don't worry too much.
 

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As above it is more about heating and the size of the top margin.

Cars with liquid cooled packs can typically be rapid charged all day long.

Even LEAF 30 can be rapid charged several times to 60-80 percent with little damage. We know that from a taxi fleet owner..

Rapid charging hot batteries to 100 percent is not good.
 

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Discussion Starter #4
I tried rapid charging and the battery temp always stayed below 15°C. Where is the dangerous heat here?
 

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Hello,
I own the skoda Citigo e iv (32kWh) that can charge at around 35 kW from 0 to 30% and then drops drastically afterwards. See graph here Ladetest Skoda CITIGOe iV
The manual says this type of charge should be avoided due to the permanent loss in capacity.
I was wondering if for this car is really that important compared to the type 2 charging (7kW and below) in terms of battery wear.
Do lithium batteries in general really suffer from close to 1C charing for just a short amount of time?
1c is not stressing your battery pack really, it’a nearer a 36 kWh battery anyway isn’t it?

All batteries degrade in use, even when charged slowly, it’s age and cycles that get to them in the end and you can’t stop that if you use them.

My e-Golf is about 18 months old, and 27k miles, it’s been rapid DC charged 2 or 3 times a week it’s whole life, as well as home charging, and doesn’t suffer any degradation I’ve noticed. There will be some I’m sure, it can’t cheat physics, but the pack is under warranty for another 6.5 years and 73k miles, so I give it about as much thought as I did engine wear when I owned my ICE car. Not a lot then!
 

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I tried rapid charging and the battery temp always stayed below 15°C. Where is the dangerous heat here?
1C refers to charging rate not ambient temperature.

For example charging a 40kWh pack at 40kW is a 1C charging rate.
 

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Discussion Starter #7
I know of course... I was saying that those temps don't look like dangerous heat territory.
 

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If you rapid charge a car with a cool battery* (ie just after starting it in the morning) it will be fine.

If you've ripped down the motorway and plop it straight on a rapid it will start to warm up nicely.

With passive battery cooling and a couple of back-to-back rapid charges temperatures of 40+C start to become possible.


* Li-ion batteries can be damaged if charged below 0C(entigrade) so most will divert energy to warm the pack if it is very cold before filling the cells (assuming battery heating is present). Due to the size of the pack it would normally need persistent freezing weather and a few days of not using the car to get a truly frozen battery in the UK.
 

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I know of course... I was saying that those temps don't look like dangerous heat territory.
Sorry, I missed that you were also the OP.

15 degrees C should be fine. I've gotten LEAF 24 and 30 up close to the red a few times. 3 rapid charges in one day + 65mph driving will do it.

LEAF temp gauge also considers state of charge. The segements have ranges that overlap.

Temperature bar 7 out of 12 could be as hot as 47 centigrade. That is easy to do on a long trip.

I manged to get our LEAF to bar 10 a few times. That is 49 to 56. The first red bar (11) is 52 to 59.
 

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Ioniq 38kwh 2020
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Hello,
I own the skoda Citigo e iv (32kWh) that can charge at around 35 kW from 0 to 30% and then drops drastically afterwards. See graph here Ladetest Skoda CITIGOe iV
The manual says this type of charge should be avoided due to the permanent loss in capacity.
I was wondering if for this car is really that important compared to the type 2 charging (7kW and below) in terms of battery wear.
Do lithium batteries in general really suffer from close to 1C charing for just a short amount of time?
I don't think it should. but when rapid charging my Ioniq 38kWh (which usually never gets close to 1C, fastest I've ever seen is about 41kW) it does seem to "over report" the SOC as if I then park up after a rapid charge, the SOC drops over the next few days by as much as a 3-4% (which doesn't happen if I slow charge). So it's doing something that may not be especially good for battery health.
 

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Discussion Starter #14
I noticed that while charging at DC stations the voltage is 315 and current 100A, considering the battery is 60Ah isn't that well above 1C and very stressful for the battery?
 

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The 50kW nominal rapid chargers can go as high as 125A. Cars can throttle down as required.

I don't have data sheets for the modules used in production EVs. I doubt they are available publicly.

We can get data sheets for industrial cells.

For example here is the Samsung INR18650-30Q. This battery has been around since 2015.



Rated 2.950Ah minium

Rated charge is 4A. or 1.355C. Rated charge temperature 0 to 50℃ recommend stop charging at 45℃



Samsung INR21700-40T Rated capacty 3.9Ah Rated Charge 6A or 1.5C.

(I'll let you find the data sheet for that one.)
 

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Discussion Starter #16
Hi,
are you trying to say that current is safe?
I'm pretty sure it's safe since they allow it, I was wondering if in this case it really makes a difference compared to slow charging in terms of permanent damage.
Even though C-rates are in amp/hour and considering it can charge 26kWh (0-80%) in hour and it means in hour we do not know charge above 1C since the battery is 36.8kWh. I'm not sure if I need to consider the Ah or the kWh for the C-rates stuff because if the first minute we do apply a current above the rating while the kW is well below the kWh capacity.
Can we damage a battery if supercharged only for a small amount of its capacity?

Let's say we want to charge a 1kWh battery at 2C for the first half and then 0.1C for the second half and the final result is that we charged at 1C, is the same at charging at constant current or did we damage the first part of the battery? I'm course talking about a continuous use like this.
 

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Sounds like a manufacturer CYA clause to cover you doing a rapid after leaving your non- actively-cooled battery almost empty in Spanish 40 degree heat for a day. An edge case.
 
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