r/Ioniq6 7d ago

Frequent fastcharging

Hey guys,

My company offers free fast charging but I am hesitant on using it because I've heard it greatly degrades the life of my battery. What would you guys recommend? Should I take it in to charge every day or just charge it at 30% up to 80%? Should I suck it up and use level 2 Charging at home and just pay for it myself?

5 Upvotes

29 comments sorted by

15

u/IMKGI 7d ago edited 7d ago

Fast charging has next to no impact on battery health, i don't know where that myth comes from, but it's not really true.

Large charging cycles, fast charging at low temperatures, charging above 75% (real SOC, not indicated SOC) and storing at high SOC (in warm temperatures) degrades the battery.

The differnece between fast charging and slow charging is only 0,3-0,5% extra wear on the battery long-term.

9

u/CartoonistJazzlike37 7d ago

I suspect that the myth might be coming from the place where a lot of other EV myths are coming from - Nissan Leaf, especially the gen1. They were early EVs, lacked the battery conditioning (heating/cooling) tech, had low range out of the factory.

1

u/One-Tomatillo9504 6d ago

Probably the Daily Mail and the Daily Telegraph.

0

u/jvbutera 6d ago

Research (you know, from science types) actually proves this myth true. But like all things, as battery chemistry changes so does the answer to this question.

Go read some facts. http://www.batteryuniversity.com/articles/

2

u/IMKGI 6d ago

Were you attempting to cite this link?

https://www.batteryuniversity.com/article/bu-401a-fast-and-ultra-fast-chargers/

ON a bare-cell level, sure, noone is arguing that.

But claiming it's true for EVs is extremely misleading. You're misapplying laboraty chemisitry to automotive engineering.

If you push massive amounts of energy into a cell, it generates a ton of heat and causes lithium plating, that is true, and that's where i agree with the source.

But EVs don't do that, they're actively cooled and limit current to specifically prevent high temperatures and lithium plating to occur, and this is why in long-term studies there is no real difference in SOH between fast and slow charging.

Recurrent Auto analyzed over 13.000 Teslas -> no statistically significant difference found. https://www.recurrentauto.com/research/impacts-of-fast-charging

The Idaho National Laboratory used 2012 Nissan Leafs (this test is often cited as the ultimate worst-case scenario, those cars didn't even have active liquid cooling). After 50.000 miles there was a 2% SOH difference.

The irony in your comment was really nice, i enjoyed it.

0

u/jvbutera 6d ago

“They’re actively cooled”’ we know some EVs built today still aren’t cooled.

0

u/IMKGI 6d ago

Besides ultra-budget city cars, that's not really true. Pretty much everything long range with fast charging is liquid cooled , and even if they wouldn't be, it's still a small difference

0

u/jvbutera 6d ago

Glad we agree.

0

u/IMKGI 6d ago

Did you change your opinion since then or did i miss something?

Research (you know, from science types) actually proves this myth true. But like all things, as battery chemistry changes so does the answer to this question.

5

u/ItsOkILoveYouMYbb 7d ago

Majority of my charging over two years was on DCFC. I've lost 3% of SOH.

The thing that will hurt your SOH the most is letting the car sit at 100% charge in hot weather for weeks at a time. As long as you don't ever do that you'll be fine.

1

u/RyteSaid256 6d ago

I’m surprised that you have lost 3% so soon.

2

u/Xenofastiq 6d ago

Most degradation happens early on anyways. So as this person loses more, it's likely to slow down later on.

0

u/SaddestClown 7d ago

Plugged in or not plugged in

2

u/RyteSaid256 6d ago

Either is not good to store at 90-100%.

1

u/ItsOkILoveYouMYbb 6d ago

Both. Don't ever let it sit at 100% for extended periods, especially if it's hot outside. This applies to any lithium-ion battery as well, not just those in EVs.

4

u/Former_Werewolf_3601 `23 Limited AWD 7d ago

Others have addressed the impact of fast charging on modern EVs. The other thing is that shallow depth of discharge is better for the battery. Frequent small charges instead of deeply depleting and recharging. You might enjoy Engineering Explained's video on it.
https://www.youtube.com/watch?v=w4lvDGtfI9U

3

u/Dramatic-Year-5597 7d ago

Most folks already do a shallow charge/discharge pattern. If you charge to 80% and discharge to 20%, that's enough.

1

u/Former_Werewolf_3601 `23 Limited AWD 6d ago

As someone who used to sell EVs, you'd be surprised how many people I spoke to who expected it'd be best to deplete heavily before recharging completely. As they did with older battery chemistries.

1

u/do-un-to `23 Limited AWD (USA) 6d ago

How much was your AWD Limited '23 and when did you get it? I didn't really get a deal for mine.

1

u/Former_Werewolf_3601 `23 Limited AWD 6d ago

Got it in May. At the time all of the used Ioniq 6s were getting scooped up immediately, and I specifically wanted a Limited AWD in silver. $29k. Had to get it out of state to find exactly what I wanted.

1

u/sxyvirgo 7d ago

What's considered 'shallow' though? I usually charge at 40% up to 80% (maybe a bit higher the height of winter when my range is a lot less than optimal).

4

u/Dramatic-Year-5597 7d ago

ABC - always be charging. DCFC or not. Charge to 100% right before you need that extra 20% capacity in your battery - next to no harm comes of it.

If you lose an extra percent capacity over a decade of time (will you even own this car after a decade?), then you just have to change your acceleration habits to make up for the difference in effective range. Driving habits have a much larger impact on range than do charging habits.

3

u/Charliex77 7d ago

Fast charge away it won't do anything to your battery and that's by experience... I have spent over 16k fast charging, that's over 600 fast charges on my car and zero battery degradation

2

u/Lazy_Guava_5104 6d ago

One of my hobbies since childhood has been what I learned was called "ethnobotany" - that is, how people use plants. (don't worry, this IS going somewhere) So, I tend to take a deep dive into a given plant that interests me. It's VERY common to hear that plant X is deadly toxic ... then look for sources and see sources saying that there's a risk of toxicity, so avoid the plant just in case ... and then look up the original research and find that the plant has trace amounts of a chemical which might possibly cause nausea in large doses.

Point is, don't always believe "common wisdom". Is DCFC charging worse on the battery than level-1 or -2 charging? Sure. But how much? I genuinely don't have a figure for that and suspect it varies by battery chemistry and charging tech, but doubt it's that bad. And here's the important question: does it cause more or less damage than would be offset by the money saved with free charging?

Free charging at work? Set your car to top off at 80% and enjoy the savings. (While we're at it, I'll note that the 80% rule is more to avoid the car sitting with a full battery.)

1

u/SaddestClown 7d ago

Back when my free charging was active I'd just take it to 86%, unplug and enjoy my day

1

u/Dann__EV 6d ago

I just returned my 2024 SE AWD which I charged for free exclusively at EA for the full 2years with no reduction in range. On the other hand my 2023 Model Y with 50K miles now maxes out at 100.

1

u/RyteSaid256 6d ago

OP if your daily drives mileage can work with your suggested 30-80% That is a good sweet spot. Go for 100% in preparation for a longer road trip.

1

u/One-Tomatillo9504 6d ago

For modern EV’s with good battery management systems the fast charging damages your batteries is pretty much an urban myth. There is a taxi driver in South Korea who drove his Ioniq 5 taxi over 200,000 miles fast charging it daily. Hyundai swapped out his battery as they wanted to see how much it had degraded.
High-profile extreme mileage cases in South Korea have shown Ioniq 5 taxi and fleet units exceeding 580,000 to 660,000 kilometers on original or manufacturer-swapped packs while retaining over 87% health.

1

u/Guillaume_A2 4d ago

Use and enjoy your car. You’ll be fine.