MG4 LFP/NMC batteries

[tsedge]

How about the battery life of LTP in comparison to NMC? Do you think the SR (LTP) will write off less in comparison to the LR (NMC)?

No, not really, because the degradation with any type of battery is irrelevant unless you do a zillion miles. With the LR, 250 miles per cycle means you'll get 125,000 miles out of 500 cycles, which is negligible degradation. It will matter if you are a taxi driver or one of those million milers, but not otherwise.

Batteries of both types will outlive the vehicle and be repurposed as stationary storage for decades, most likely.

 

[BugEyed]

All this is really moot though, buy the one that suits you best whether that's range/cost/spec.

^^^ The best advice ^^^

MG in their wisdom have added two bits of confusion into this.

• The Trophy with the additional kit only being available with the NMC
• The LFP having a lower power and lower geared motor giving better low speed performance at the expense of high speed efficiency

 

[memo]

That is a good insight indeed. Thank you. I have also read this report about battery health. It seems like LFP batteries last much much longer than NMC batteries. The following is stated in the report.

View attachment 13142

Remember as well, this study is 2 years old (as with all things tech it moves on at a pace) and was for 18650 cells, the type you will find in laptops, RC, and early teslas. Where'as there is some correlation because of the chemistry, the cells in the MG4 are I believe pouch cells and are the latest available.

I'm sure i read somewhere on a MG4 website that these latest NMC batteries in the LR have a cycle life of up to 2000 cycles. Elsewhere I read that generally the latest vehicle NMC batteries have a cycle life of between 1500 and 2000 cycle life and LFP between 2000 and 5000 cycle life, so yes the LFP will, in theory, at least, last longer.

But...

If we only assume the MG4's NMC battery is 1500 cycle life and only 250 miles per cycle thats still, in theory 375,000 miles (604,000 klm). I suspect the car will be dead and crushed before it gets to that kind of mileage for many more reasons than the battery and I for sure will not be owning it.

 

[eak1111]

โปรดจำไว้ว่าการศึกษานี้มีอายุ 2 ปี (เช่นเดียวกับทุกสิ่งที่เทคโนโลยีก้าวไปข้างหน้า) และเป็นเซลล์ 18650 ชนิดที่คุณจะพบในแล็ปท็อป RC และเทสลารุ่นแรกๆ ในขณะที่มีความสัมพันธ์กันเนื่องจากคุณสมบัติทางเคมี ฉันเชื่อว่าเซลล์ใน MG4 เป็นเซลล์กระเป๋าและเป็นเซลล์ล่าสุดที่มีอยู่

ฉันแน่ใจว่าฉันอ่านที่ไหนสักแห่งบนเว็บไซต์ MG4 ว่าแบตเตอรี่ NMC รุ่นล่าสุดใน LR มีอายุการใช้งานสูงสุด 2,000 รอบ ที่อื่นฉันอ่านมาว่าโดยทั่วไปแล้วแบตเตอรี่ NMC ของรถยนต์รุ่นล่าสุดมีอายุการใช้งานระหว่าง 1,500 ถึง 2,000 รอบและ LFP ระหว่าง 2,000 ถึง 5,000 รอบ ดังนั้นตามทฤษฎีแล้ว LFP จะมีอายุการใช้งานนานกว่าเป็นอย่างน้อย

แต่...

หากเราสันนิษฐานว่าแบตเตอรี่ NMC ของ MG4 มีอายุการใช้งาน 1,500 รอบและเพียง 250 ไมล์ต่อรอบ ซึ่งตามทฤษฎีแล้วยังคงอยู่ที่ 375,000 ไมล์ (604,000 klm) ฉันสงสัยว่ารถจะตายและถูกบดขยี้ก่อนที่จะถึงระยะดังกล่าวด้วยเหตุผลหลายประการมากกว่าแบตเตอรี่และฉันจะไม่เป็นเจ้าของมันอย่างแน่นอน

BU-205: Types of Lithium-ion

Become familiar with the many different types of lithium-ion batteries: Lithium Cobalt Oxide, Lithium Manganese Oxide, Lithium Iron Phosphate and more.

batteryuniversity.com

 

[Kithmo]

What is classed as a charge cycle ?
Is charging from say 10% to 100% counted as 1 cycle ?
Is charging from 50% to 80% also counted as 1 cycle or part of a cycle ?

 

[Stageshoot]

What is classed as a charge cycle ?
Is charging from say 10% to 100% counted as 1 cycle ?
Is charging from 50% to 80% also counted as 1 cycle or part of a cycle ?

A Charge cycle is 0-100% so if you charge from say 20% to 70% that would be 1/2 a cycle

 

[Avro]

With Lithium cells1 cycle is usually classed as 0% to 100%
As mentioned above pretty much all of these quoted battery performance tables are based on lab tests of single comercial cells, I have yet to see a fully documented test of an automotive grade battery pack which would have considerably different chemistry to the these single cell tests.
In my opinion this guy seems to be believable

Battery Life

 

[Martijn]

With Lithium cells1 cycle is usually classed as 0% to 100%
As mentioned above pretty much all of these quoted battery performance tables are based on lab tests of single comercial cells, I have yet to see a fully documented test of an automotive grade battery pack which would have considerably different chemistry to the these single cell tests.
In my opinion this guy seems to be believable

Battery Life

This is a very interesting video. I watched some more videos on the channel and I also stumbled on the video below. Around the 3 minute mark there is a very interesting graph showing results from Tesla batteries (using a slightly different battery technique though). That gives me more faith in NMC batteries.

 

[MoDolph]

A common mistake people are making is extrapolating cycles to time which is not valid. There are 2 main factors that lead to degradation; time and cycles. Scientists performing studies usually try to separate the two factors where possible so cycle data will be performed as quickly as possible and the time studies (calendar aging) will be performed without cycling.

In the real world degradation will be the sum of both mechanisms. A good battery will balance the two.

If you plan to drive 200 miles twice a day then the cycle data is probably quite accurate. If you plan to rarely drive the car then the calendar aging data is more representative. Realistically it will be somewhere in the middle.

The LEAF taxi in the video managed so many miles because it did them in a short time. My LEAF is also down two bars but has only done 60,000 miles because the time element dominated.

It's simply not the case that because a study shows a battery can do 2000 cycles that it means it will last 40 years because you only do 10k miles per year. The calendar aging will have killed it long before then.

LFP is good at cycles but similar over time:

LFP is better, but it's not some magic, never degrading chemistry.

 

[Stageshoot]

A common mistake people are making is extrapolating cycles to time which is not valid. There are 2 main factors that lead to degradation; time and cycles. Scientists performing studies usually try to separate the two factors where possible so cycle data will be performed as quickly as possible and the time studies (calendar aging) will be performed without cycling.

In the real world degradation will be the sum of both mechanisms. A good battery will balance the two.

If you plan to drive 200 miles twice a day then the cycle data is probably quite accurate. If you plan to rarely drive the car then the calendar aging data is more representative. Realistically it will be somewhere in the middle.

The LEAF taxi in the video managed so many miles because it did them in a short time. My LEAF is also down two bars but has only done 60,000 miles because the time element dominated.

It's simply not the case that because a study shows a battery can do 2000 cycles that it means it will last 40 years because you only do 10k miles per year. The calendar aging will have killed it long before then.

LFP is good at cycles but similar over time:

View attachment 13170

LFP is better, but it's not some magic, never degrading chemistry.

Yep time is probably the biggest factor for most normal mileage drivers. Something that is often overlooked.

But I honestly think whichever battery you get, the condition of the car will condemn it before the battery SOH does.

 

[tsedge]

A common mistake people are making is extrapolating cycles to time which is not valid. There are 2 main factors that lead to degradation; time and cycles. Scientists performing studies usually try to separate the two factors where possible so cycle data will be performed as quickly as possible and the time studies (calendar aging) will be performed without cycling.

In the real world degradation will be the sum of both mechanisms. A good battery will balance the two.

If you plan to drive 200 miles twice a day then the cycle data is probably quite accurate. If you plan to rarely drive the car then the calendar aging data is more representative. Realistically it will be somewhere in the middle.

The LEAF taxi in the video managed so many miles because it did them in a short time. My LEAF is also down two bars but has only done 60,000 miles because the time element dominated.

It's simply not the case that because a study shows a battery can do 2000 cycles that it means it will last 40 years because you only do 10k miles per year. The calendar aging will have killed it long before then.

LFP is good at cycles but similar over time:

View attachment 13170

LFP is better, but it's not some magic, never degrading chemistry.

Yes, this is all true, however the Leaf doesn’t have active battery thermal management so suffers much more battery degradation than more modern designs of any chemistry.

The real world reports I have heard have all said a similar thing: yes, there’s some degradation over years / many miles but not a lot and it is only if you do many miles or keep it for years that a replacement is needed - and this is typically the same or longer than the lifespan of an ICE vehicle engine.

Edit: repurposing as static storage does not require a high remaining capacity. A pack with 40% capacity can still be useful. Whether this typically happens will depend on the economics: is it cheaper to buy new storage or recycle old?

 

[MoDolph]

All good points. MG themselves think that the NMC battery will be good for 12 years and 1M km if google translate is correct, not quite the 20 years that I would want but still good:

 

[Martijn]

The LFP having a lower power and lower geared motor giving better low speed performance at the expense of high speed efficiency

I can't find more information on this online. I am curious about the difference this would make. Does anybody have more information on this?

 

[maverickz]

All good points. MG themselves think that the NMC battery will be good for 12 years and 1M km if google translate is correct, not quite the 20 years that I would want but still good:



the google translate is correct for this case.

 

[bribagz]

So, I did a video on getting a pre-order of an MG4 in Australia:


One of the commenters said the MG4 base has an LFP battery, and the others have NMC. I didn't believe it at first (none of the YouTube reviews said this iirc), but checked on it and it's true apparently:

MG MG4 Electric - Battery type

MG MG4 Electric (all model variants) - Battery type: Lithium Iron Phosphate (LFP), Lithium Nickel Manganese Cobalt (NMC)

www.myevreview.com

I'm assuming they went NMC on the LR and Trophy due to the extra weight an LFP would be.

Another commenter (Wildreefer) said:
"according to my calculations, the LR versions @80% have almost the exact same range as the SR (LFP) version @100% - so basically all you're getting on the LR version is the ability to go to 100% from time to time for longer trips. Not sure if that's worth the extra money, but for some it may be worthwhile."

Which is a good question.

So, does this change what you would choose?

I was thinking the LR would be the best option, if the Trophy was too much more, but now I'm not so sure.

Thoughts??

I have LFP. quite happy.

 

[Brettus]

I have LFP. quite happy.

Wow that was quite a blast from the past for reanimation. Glad you are though

 

[Haggis]

In practice, nobody has reported getting over 87kW with the SR, so the LR is significantly better for a fast charge.

The reason for having a bigger battery is the ability to use it to 100% when you are doing a long journey. There is no problem charging to 100% so long as it isn’t left for a long period of time at that state of charge.

LFP is great for safety and cheaper and if that’s all you need fantastic. But there are advantages in the NMC battery.

Edit: Also people are getting 11kW AC charging with the LR (with suitable cable and charger), as stated in the manual.

LFP can charge 2000 times. NCM does 500 times charges. Big difference right there.

I guess that's great. You can fast charge a NMC a bit quicker. Risk assessment is it may get thermal runaway or explode. And you just used one of your only 500 cycles. You get 5 times or more cycles with LFP. LFP was more expensive no so long ago. But now with the slave child labour in Africa mining cobalt for some reason it's now more expensive. Perhaps it's to pay for the guy with the AK47 pointed at the child's head. I'm only guessing. So unless you are getting rid of your EV quite soon I would suggest against NMC. Plus would you buy a 2nd hand EV that's a few years old with a NMC battery? You would be mad to do that. But you may if it's LFP. Not NMC. Tesla is changing to LFP. Most manufacturers are. So the guy selling his 2nd hand EV with a NMC battery will be up against much better vehicles for sale.

 

[Rolfe]

I think you undersell the NMC battery quite badly. Although there is a greater risk of thermal runaway with the NMC than with the LFP it's still a very low risk. I'm also not sure of the number of cycles you can get from an NMC but I'm pretty sure it's more than 500. They are predicted to last as long as the car. The older EVs running around with 100s of 1000s of miles on the clock will mostly have NMC batteries.

 

[jpk]

LFP can charge 2000 times. NCM does 500 times charges. Big difference right there.

Where did you pull those random figures from!

 

[tsedge]

I guess that's great. You can fast charge a NMC a bit quicker. Risk assessment is it may get thermal runaway or explode. And you just used one of your only 500 cycles. You get 5 times or more cycles with LFP. LFP was more expensive no so long ago. But now with the slave child labour in Africa mining cobalt for some reason it's now more expensive. Perhaps it's to pay for the guy with the AK47 pointed at the child's head. I'm only guessing. So unless you are getting rid of your EV quite soon I would suggest against NMC. Plus would you buy a 2nd hand EV that's a few years old with a NMC battery? You would be mad to do that. But you may if it's LFP. Not NMC. Tesla is changing to LFP. Most manufacturers are. So the guy selling his 2nd hand EV with a NMC battery will be up against much better vehicles for sale.

Ridiculous misinformation!

NMC lifespan is easily >200,000 miles which is good enough for anyone who is not a taxi driver, new or second hand through 10-15 years.

Explosion/fire risk is tiny and far less than with ICE, which people never think about.

Regarding mining practices, there's a steady effort to reduce the dependency on cobalt, plus plenty of other modern devices use rare earths (practically) all tech so I don't know whether you borrowed someone's computer or phone but if you have your own you are guilty of the same crime and could be called a hypocrite.

Please stop spouting nonsense.