LFP battery vs. NCM

[737flyer]

LFP batteries degrade much more slowly than NMC. If you're only going to keep the car for a couple years, this may not matter. But if you tend to keep cars for a long time (like me), the range difference will become smaller as the battery naturally degrades.

https://www.engineering.com/story/why-ev-manufacturers-are-switching-from-nmc-to-lfp-batteries

I got my Premium RWD SR LFP almost a month ago. One of the things that drew me to the Mach E over some of its competitors was the LFP battery.

what’s the charge rate from 10%-100%. Does it stay constant?

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[Neandrewthal]

LFP batteries degrade much more slowly than NMC. If you're only going to keep the car for a couple years, this may not matter. But if you tend to keep cars for a long time (like me), the range difference will become smaller as the battery naturally degrades.

https://www.engineering.com/story/why-ev-manufacturers-are-switching-from-nmc-to-lfp-batteries

I got my Premium RWD SR LFP almost a month ago. One of the things that drew me to the Mach E over some of its competitors was the LFP battery.

I mean 1000 EFC gets you your range times 1000 in total miles, so it doesn't seem like much to be concerned about before you're at 80% initial capacity.

 

[737flyer]

I mean 1000 EFC gets you your range times 1000 in total miles, so it doesn't seem like much to be concerned about before you're at 80% initial capacity.

I’m a little confused with your answer.
My MME starts charging at 150kwh then drops to 110kwh to 80% then 40kwh to 90%

 

[Neandrewthal]

I’m a little confused with your answer.
My MME starts charging at 150kwh then drops to 110kwh to 80% then 40kwh to 90%

I was referring to the conversation about battery degradation. The chart showed that NMC batteries might expect 1000 EFC (equivalent full charges, so 2000 charged from 30-80% or 10,000 charges from 80-90% for example). 1000 EFCs is 1000 times your range, which is quite a lot of miles for a car to last. If your real world range averages 250 miles, then you can expect around 250,000 miles of life before your battery only has 80% of its initial capacity available.

Edit: The chart you commented on is not a charge curve.

 

[Mach1E]

I mean 1000 EFC gets you your range times 1000 in total miles, so it doesn't seem like much to be concerned about before you're at 80% initial capacity.

Not only that, if that’s the test that’s been floating around for a while, they fully charge and discharge from 0% to 100% and repeat. It’s also not a full size temperature controlled Bev battery, it’s a small battery they’re testing.

Nobody drives their car like that, and even if you did, you’re talking a 20% loss in 300,000 miles.

Not why you would buy a battery that starts with 20% less range in the hopes that the gap would shrink to 15% less in 300,000 miles.

 

[SWO]

Even at 90%, I'd gain only 38 miles with the extended range.

Go to abetterrouteplanner.com and experiment having it calculate routes with the SR vs ER packs. For a 1k mi trip it's going to potentially add hours having the SR pack.

 

[c-had]

I mean 1000 EFC gets you your range times 1000 in total miles, so it doesn't seem like much to be concerned about before you're at 80% initial capacity.

Yeah, it'll vary depending on how gentle someone is with their battery, but for folks that are careful the degradation will be negligible until they're getting upward of 100k miles. At that point, you've got a median of maybe 20 miles of range loss in NCM, while the LFP might only be 5 miles of range loss. So, a 45 mile difference in range rather than 60 when new.

 

[c-had]

Go to abetterrouteplanner.com and experiment having it calculate routes with the SR vs ER packs. For a 1k mi trip it's going to potentially add hours having the SR pack.

I believe that's true in large part because ABRP hasn't been updated with the LFP battery. The old SR battery had a max DC charge speed of 115kW and went 10-80% in 38 minutes. The new LFP has a max DC charge speed of 150kW and a 10-80% in 33 minutes. The LFP battery will charge at a similar rate as the ER battery. The ER is still better for road tripping, but the difference with the LFP battery is more like minutes than hours.

 

[bbulkow]

I chose ER because I borrowed a friend's Tesla that was more like an SR mache, and often found days when I had so many errands that I was nervous and fast charging. I live in the SF bay area and it's like 15% round trip to oakland, and another 15% RT to SF. I have had days when I got to SF twice and oakland once, from my house, because I'm an idiot and forgot things.

I think if you *don't* have a charger at home, you'll care more about range. Less when you have your charger.

SF LFP wasn't available, so the price difference between the two was less.

I liked the higher fast charge speeds, the (probably) better battery life. Not unhappy with my choice. Doing it again... would consider SR.

 

[SWO]

I believe that's true in large part because ABRP hasn't been updated with the LFP battery. The old SR battery had a max DC charge speed of 115kW and went 10-80% in 38 minutes. The new LFP has a max DC charge speed of 150kW and a 10-80% in 33 minutes. The LFP battery will charge at a similar rate as the ER battery. The ER is still better for road tripping, but the difference with the LFP battery is more like minutes than hours.

Ok, I didn't know the LFP batteries charged faster. Is there any real world test data out there?

 

[George Knighton]

And here comes the dumb old man from out of left field.

LFP has some real advantages that I wish more manufacturers would utilise. Any time you want to change directions with manufacturing, however, you introduce costs that companies have to think about carefully.

Buy LFP from China, maybe. That'd be easy but at the expense of bad publicity about losing the tax rebate, and, well...Chinese.

LFP is easy to make, but there are compromises that the end user has to think about.

LFP is usually slower to charge. We already think that our Mach-E are slow charging. If you have the time, have a look at all the Tesla owners on YouTube complaining about how slow their cars charge.

LFP is heavier than NMC for a given energy density. This is why you'll find LFP in the cheaper base models where the purchaser might expect to have a lower range.

Even the basically cheap, popular MG4 uses LFP only in its base 51 kWh versions. The 64 kWh and 77 kWh versions are NMC.

The 90% v. 100% argument might have. some validity but if an NMC owner has to go on a longer trip, he'll just charge to 100% and have more range than the model with LFP.

So at this point we shouldn't be anti-LFP because it has its place, but it's not ready for NMC prime time in bigger, longer range, more expensive vehicles.

 

[George Knighton]

Let me say that coming to the GT PE from a Chevy Bolt EV, all the slow charging complaints don't hold water with me.



I stopped by an EA station yesterday just to make sure that Plug and Charge worked. I was at 75%, did not need a charge, but I just wanted to be sure it worked.

Screen says de-rated for an update.

Well. Fine. I just want to be sure it works.

Plug in. Not instant. Takes about three times the time a Tesla station would have taken to go through initialisation.

But it worked.

45 kW derated speed from 75% to 80%.

That's awful, but it's about what a Chevy Bolt would do in the best of times.

So...whatever. It's great car. ?

 

[DaMeatMan]

LFP battery = charge to 100% = 250 mile range
Extended Range battery 320 mile range, BUT recommended max 80% charge = 256 miles
Seems pretty close to me. What am I missing except for $7k?

The LFP chemistry benefit from very important characteristics.

1) You can safely charge to 100% as you already stated.

2) They are rated for a cycle life of 4000 cycles while retaining 80% of their original capacity, and this is rated with 100% charging. It can last much much longer if you dont charge to 100%. This is DOUBLE the cycle life of NMC chemistry which is rated for approximately 2000 cycles while charging to 80%.

3) LFP is a very stable battery chemistry, with very low likelihood of thermal runaway (fire), in the event of a crash, short, battery malfunction, or mistreating the cells. In fact many cells (depending on form factor) can be physically pierced with a nail, or cut, and only get warm, and do not combust. NMC on the other hand will readily combust in the same scenario.

 

[Mach1E]

The LFP chemistry benefit from very important characteristics.

1) You can safely charge to 100% as you already stated.

2) They are rated for a cycle life of 4000 cycles while retaining 80% of their original capacity, and this is rated with 100% charging. It can last much much longer if you dont charge to 100%. This is DOUBLE the cycle life of NMC chemistry which is rated for approximately 2000 cycles while charging to 80%.

3) LFP is a very stable battery chemistry, with very low likelihood of thermal runaway (fire), in the event of a crash, short, battery malfunction, or mistreating the cells. In fact many cells (depending on form factor) can be physically pierced with a nail, or cut, and only get warm, and do not combust. NMC on the other hand will readily combust in the same scenario.

Is #2 actually a benefit that will benefit anyone?

Its starting EPA range is 250 miles.
4000 cycles is 1 million miles.

So after 1 million miles the range will be 200 miles.

Compare to an ER vehicle-
312 miles starting range
2000 cycles 624,000 miles

After 624k miles range will be 250 miles….

Still more range than a SR vehicle would have even after 624,000 miles. And like you said this is more worst case if you always charge to 100%.

So I don’t think this will have any real world benefit to anyone.

 

[George Knighton]

Care to elaborate on where the "NCM" comes from?

No, I would not care to elaborate.

You have a point.

Manufacturers are improving sourcing but at the moment, yes, you have a point.

Whether you can convince the buying public and the manufacturers that this is enough of a point to change what they do is not beyond all conjecture, but you'll excuse me if I suggest it is unlikely at the moment.

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