NMC vs LiFePO4

[Joseph V Chen]

Greetings All

trying to understand different battery chemistry

Is there a Real Concern that there is a
safety exposure and lower lifespan with NMC ?


…excerpt from chatgpt
Lifespan (charge cycles)

• NMC: ~1,000–2,000 cycles
• LiFePO4: ~2,500–5,000+ cycles

👉 LiFePO4 lasts 2–3× longer.

3. Safety

• NMC: More prone to overheating/thermal runaway if damaged or poorly managed
• LiFePO4: Much more stable and resistant to fire

 

[The Weatherman]

NMC - Higher power density
LiFeP04 - Lower power density.

More power per volume.

 

[Joseph V Chen]

In many real-world designs:

• Peak power density can be similar
• Sustained high-power use often favors LiFePO₄ (thermal stability)

 

[Joseph V Chen]

Lifetime cost

Cycle life:

• NMC: ~800–2,000 cycles
• LiFePO₄: ~2,000–6,000+ cycles

Real cost over time:

• NMC: ~$0.50 per kWh delivered
• LiFePO₄: ~$0.15 per kWh delivered

👉 ~60–70% cheaper long-term for LiFePO₄

 

[GaRailroader]

Real cost over time:

• NMC: ~$0.50 per kWh delivered
• LiFePO₄: ~$0.15 per kWh delivered

👉 ~60–70% cheaper long-term for LiFePO₄

Welcome to the forum Joseph. I am originally from Howard County, Ellicott City area. I find this stat the most interesting though I am very suspect of its accuracy. I think that is a very neat way to measure battery useful life depletion.

 

[ScooterAsheville]

Also, those are only two of many battery chemistries. There is a whole universe of them, and more coming in the near future. Sodium based. Manganese rich (coming from both Ford and GM). All sorts of solid state formulations.

It's the old curse. "May you live in interesting times". From following batteries closely, I think in a decade or so we'll look back at today's batteries with horror. Like bias ply tires or no antilock brakes or no crash standards. "Can you believe people used to park cars in their garages that would catch fire and burn their houses down!". In a decade, that will be ancient history.

 

[Joseph V Chen]

Welcome to the forum Joseph. I am originally from Howard County, Ellicott City area. I find this stat the most interesting though I am very suspect of its accuracy. I think that is a very neat way to measure battery useful life depletion.

Welcome to the forum Joseph. I am originally from Howard County, Ellicott City area. I find this stat the most interesting though I am very suspect of its accuracy. I think that is a very neat way to measure battery useful life depletion.

I am using chatgpt .
It is definitely not the golden source but a starting point.

 

[Joseph V Chen]

Also, those are only two of many battery chemistries. There is a whole universe of them, and more coming in the near future. Sodium based. Manganese rich (coming from both Ford and GM). All sorts of solid state formulations.

It's the old curse. "May you live in interesting times". From following batteries closely, I think in a decade or so we'll look back at today's batteries with horror. Like bias ply tires or no antilock brakes or no crash standards. "Can you believe people used to park cars in their garages that would catch fire and burn their houses down!". In a decade, that will be ancient history.

I am more focused on deliverables
not the past or ‘far’ future.

• Sodium-ion EVs are almost entirely in China (2026)
• 
  
• No mainstream U.S. or European models years
• 
  
• Most EVs today (already use manganese)
• 
  
• no EV cars you can buy today (2026).
  Fully solid-state battery EVs are still in development not in production.

 

[phidauex]

Hi, please do not use chatgpt for this - it is very wrong in this case, particularly on the cycle life question, and somewhat on the safety question.

NMC and Lifepo batteries can both fail catastrophically, and the biggest cause is manufacturing defects. I'd take a good quality NMC battery over a poor quality Lifepo any day. If quality is identical, then the lifepo will have slightly lower chance of thermal runaway, which is a positive.

Lifepo batteries have long cycle lives, but they also tend to degrade faster overall. The apparent reason for the longer cycle life is that they can often be run to lower states of health, so if you can run one battery all the way down to 60% SOH, but the other is dead at 70% SOH, then the first "lasts longer" even if it is actually degrading faster. This is an important dynamic for grid scale battery systems.

For vehicles it is close to a wash. You need NMC to hit the higher energy densities needed for the longest ranges, but lifepo is cheaper and has gotten quite a bit more reliable over time.

 

[ScooterAsheville]

I spent endless hours chatting with a battery engineer friend back in the day. He designed batteries for a wide range of use cases - spacecraft, military, aviation, etc. He used to roll his eyes in frustration whenever I'd present some battery article I found on the web.

What I learned from him was that if you are not a battery engineer, you are an ignoramus. Accept it and move on. And don't try to sound like you know more than you do. Batteries are an astonishingly sophisticated and complex engineering problem, filled with tradeoffs and snake pits. Talking to him always reminded me of a parametric equalizer - if you change this, then everything else changes too - and there are dozens to hundreds of things to change.

So these days, although I follow batteries exceptionally closely, I adhere to Dirty Harry's admonition: "A man's gotta know his limitations".

So, as an admittedly-ingorant layman, I mainly care about...

• Does it get me from A to B? Defining A and B as you like.
• How much does it cost?
• How fast does it charge? if that matters to me.
• How frigging heavy is it? As in, am I driving a tank with wheels that goes through tires like Doritos? And is more likely to kill pedestrians and other innocents when I wallop them texting cute baby photos to my BFF.
• Does it go in the cold? What's the range in the cold? Defining "cold" for yourself.
• Will it burn my house down and me with it? What are the odds?
• Will I get a recall notice telling me to park my car outside forever. See previous point.
• Will I get a recall notice telling me to not charge past 80%. Forever.
• Is it repairable at the module or cell level, or is it a whole-pack replacement?
• How long is the warranty?
• Will the OEM be around to honor the warranty?
• What happens if road debris dents the pack beyone manufacturer repairability guidance? Does my insurance policy cover replacing a $10,000 battery pack? Because road hazard is not typically an OEM-warrantied item.

And that's just a fraction of the things my friend would go on about. He probably had another three dozen design parameters in his head. He always used to say it's a huge juggling act that's different for every customer use case.

 

[beatle]

LFP are also terrible in the cold and should not be recharged below freezing. Tesla uses an LFP low voltage battery and it is actually actively heated above freezing before it's charged.

Sodium is tolerant of cold and is very stable, but it has even less energy density. I think this will be the 12v of the future. It also has the potential to be less expensive once it achieves some economies of scale.

The range of the Slate with LFP (or sodium) would have been too low to be practical for all but the most crowded city dweller who only road trips by train or plane. They're just not dense enough.

It's true that NMC batteries have a lower cycle lifespan, so the standard pack will only last 200-300k miles. The large pack will only be 300-400k miles.

 

[Joseph V Chen]

Hi, please do not use chatgpt for this - it is very wrong in this case, particularly on the cycle life question, and somewhat on the safety question.

NMC and Lifepo batteries can both fail catastrophically, and the biggest cause is manufacturing defects. I'd take a good quality NMC battery over a poor quality Lifepo any day. If quality is identical, then the lifepo will have slightly lower chance of thermal runaway, which is a positive.

Lifepo batteries have long cycle lives, but they also tend to degrade faster overall. The apparent reason for the longer cycle life is that they can often be run to lower states of health, so if you can run one battery all the way down to 60% SOH, but the other is dead at 70% SOH, then the first "lasts longer" even if it is actually degrading faster. This is an important dynamic for grid scale battery systems.

For vehicles it is close to a wash. You need NMC to hit the higher energy densities needed for the longest ranges, but lifepo is cheaper and has gotten quite a bit more reliable over time.

Thank you for this very informative reply. I most definitely agree chatgpt is not a golden source but it is a starting point ( I’m digging for the details ). thanks again

 

[Joseph V Chen]

LFP are also terrible in the cold and should not be recharged below freezing. Tesla uses an LFP low voltage battery and it is actually actively heated above freezing before it's charged.

Sodium is tolerant of cold and is very stable, but it has even less energy density. I think this will be the 12v of the future. It also has the potential to be less expensive once it achieves some economies of scale.

The range of the Slate with LFP (or sodium) would have been too low to be practical for all but the most crowded city dweller who only road trips by train or plane. They're just not dense enough.

It's true that NMC batteries have a lower cycle lifespan, so the standard pack will only last 200-300k miles. The large pack will only be 300-400k miles.

Had to ask where are you obtaining the lifespan numbers?
Is there a published Slate release?
Thanks

 

[ScooterAsheville]

A nice source in case anyone is thinking of buying a used BEV...

https://www.recurrentauto.com/

 

[beatle]

Had to ask where are you obtaining the lifespan numbers?
Is there a published Slate release?
Thanks

Just Google NMC and LFP lifespans, then compute based on the size of the Slate battery. A smaller battery will require more cycles to go the same distance.