NMC or LiFePO4 based on kWh price and budget?

[Nick0016]

Hi all,

After reading a lot about LifePO4 safety I am now a bit scared to use NMC even though when used within the specs they both are safe...

The price for LifePO4 is about 150-160 EUR per kWh (B-grade 4000 cycles) and 190-200 EUR per kWh (A-grade 6000 cycles).
The price for NMC is about 100-110 EUR per kWh (B-grade 4000 cycles).

This is a big difference when you go for ~40 kWh capacity.

Location will be indoor, room temperature. No option to place the batteries outside.

Which chemistry would you choose accounting the costs. I don't really have the budget for LifePO4 though...

(It's for an powerall based on Victron).

 

[houseofancients]

NMC has a good potential to burn down your building , LiFoPo4 does not...
i think you should factor that in with your cost too.

if it were me, i'd keeping saving untill such time i could afford LiFePo4

 

[SeaGal]

... I don't really have the budget for LifePO4 though...

(It's for an powerall based on Victron).

Is that because you spent your budget on Victron?

I'm in the same camp as @houseofancients... Not sure I'd feel safe with 40kWh capacity indoors... that 'room temperature' you mention could end up being quite high.

Now, if it were down the bottom of the garden with a metal protective case around it (thinking Prius or Leaf here) that would be a different matter ??

 

[Nick0016]

Yep Victron stuff was indeed more expensive than expected when you count all materials @SeaGal.

Well guess starting with 20 kWh LifePO4 is better choice then.

 

[Nobodybusiness]

Hi all,

After reading a lot about LifePO4 safety I am now a bit scared to use NMC even though when used within the specs they both are safe...

The price for LifePO4 is about 150-160 EUR per kWh (B-grade 4000 cycles) and 190-200 EUR per kWh (A-grade 6000 cycles).
The price for NMC is about 100-110 EUR per kWh (B-grade 4000 cycles).

This is a big difference when you go for ~40 kWh capacity.

Location will be indoor, room temperature. No option to place the batteries outside.

Which chemistry would you choose accounting the costs. I don't really have the budget for LifePO4 though...

(It's for an powerall based on Victron).

I wouldn’t use NMC but that’s me.

Any short or overcharge or over current could burn your place down.

 

[farmhand]

Is that because you spent your budget on Victron?

I'm in the same camp as @houseofancients... Not sure I'd feel safe with 40kWh capacity indoors... that 'room temperature' you mention could end up being quite high.

Now, if it were down the bottom of the garden with a metal protective case around it (thinking Prius or Leaf here) that would be a different matter ??

Build a garden shack. I've got the Ecoflow inside, but the battery bank (to be cheap LifePO4's) is all going in the outhouse. To risky.

 

[yabert]

The price for LifePO4 is about 150-160 EUR per kWh (B-grade 4000 cycles) and 190-200 EUR per kWh (A-grade 6000 cycles).
The price for NMC is about 100-110 EUR per kWh (B-grade 4000 cycles).

This is a big difference when you go for ~40 kWh capacity.

For 40 kWh your cheapess choice is probably to find and reuse a proper EV battery.
It can end to cost 50 to 80$/kWh and you will have high quality cells, contactors, busbars, connectors, etc.

 

[houseofancients]

For 40 kWh your cheapess choice is probably to find and reuse a proper EV battery.
It can end to cost 50 to 80$/kWh and you will have high quality cells, contactors, busbars, connectors, etc.

it depends if that ev battery is lithium ion, nmc or lifepo4

the first two pose the same issue, and i would never have them in my home (again)
had tesla model s modules at one point in time, and never slept well while i had them in my home

 

[yabert]

Yeah, NCA chemistry (most Tesla) is quite dangerous in over voltage even.
NMC chemistry (most EV) is less dangerous, but still no safe.
LFP chemistry (some Tesla and other China EV) is safe in most situation.

I would like to use LFP cells for my house, but I bought a Ford Fusion battery module (NMC) for free. In fact, I paid around 50$/kWh and I end with free modules after had sold half of the modules.
My receipt to sleep well at night with my NMC battery is the 3 security steps: Inverter have HV/LV setting, the relay BMS have HV/LV setting at cells level and I add a HV/LV controller to watch the BMS.

 

[yabert]

I wouldn’t use NMC... Any short or overcharge or over current could burn your place down.

And to me it's the same for LFP. The only advantage of LFP is in overcharge event.
A short will cause a extremely rapid grow in temperature and can burn your place down.

A short will cause an extremely rapid grow in temperature (at cells or/and at short contact) and burn your place down.
An over current event can cause an extremely rapid grow in temperature (at cells) and can burn your place down.

To me, LFP cells should be considered as dangerous* than NCA or NMC chemistry or as a gallon of fuel, if you prefer, because they contain an important energy quantity who can be rapidly released.

*except that thermal runaway is way less probable.

 

[houseofancients]

And to me it's the same for LFP. The only advantage of LFP is in overcharge event.
A short will cause a extremely rapid grow in temperature and can burn your place down.

A short will cause an extremely rapid grow in temperature (at cells or/and at short contact) and burn your place down.
An over current event can cause an extremely rapid grow in temperature (at cells) and can burn your place down.

To me, LFP cells should be considered as dangerous* than NCA or NMC chemistry or as a gallon of fuel, if you prefer, because they contain an important energy quantity who can be rapidly released.

*except that thermal runaway is way less probable.

let's agree to very much disagree.
i'll just leave this here:

 

[Rednecktek]

One other thing that needs to be factored, especially if you're building a battery, is ease of use.

300Ah 48v battery = 16 LFP cells or 68Bajillion 18650's.

 

[Nick0016]

Yeah, NCA chemistry (most Tesla) is quite dangerous in over voltage even.
NMC chemistry (most EV) is less dangerous, but still no safe.
LFP chemistry (some Tesla and other China EV) is safe in most situation.

I would like to use LFP cells for my house, but I bought a Ford Fusion battery module (NMC) for free. In fact, I paid around 50$/kWh and I end with free modules after had sold half of the modules.
My receipt to sleep well at night with my NMC battery is the 3 security steps: Inverter have HV/LV setting, the relay BMS have HV/LV setting at cells level and I add a HV/LV controller to watch the BMS.

Yeah, I was thinking the same way on how to monitor them.

And to me it's the same for LFP. The only advantage of LFP is in overcharge event.
A short will cause a extremely rapid grow in temperature and can burn your place down.

A short will cause an extremely rapid grow in temperature (at cells or/and at short contact) and burn your place down.
An over current event can cause an extremely rapid grow in temperature (at cells) and can burn your place down.

To me, LFP cells should be considered as dangerous* than NCA or NMC chemistry or as a gallon of fuel, if you prefer, because they contain an important energy quantity who can be rapidly released.

*except that thermal runaway is way less probable.

Indeed so my thoughts, when used within the specs both chemistry (NCM/LFP) are evenly safe/dangerous.

let's agree to very much disagree.
i'll just leave this here:

But this is something that in normal usage will not happen, I have seen the video but I still cannot imagine how you would accomplish this when the battery is sitting nice and tight and you are using them within the specs.

That NCM is more flammable than LFP is something we know all.

Not looking for discussion, really appreciate your comment. Just trying to understand it all to make a good decision between budget/price/safety.

One other thing that needs to be factored, especially if you're building a battery, is ease of use.

300Ah 48v battery = 16 LFP cells or 68Bajillion 18650's.

Those I mentioned are also prismatic cells, same size as LFP cells.

 

[houseofancients]

Yeah, I was thinking the same way on how to monitor them.



Indeed so my thoughts, when used within the specs both chemistry (NCM/LFP) are evenly safe/dangerous.



But this is something that in normal usage will not happen, I have seen the video but I still cannot imagine how you would accomplish this when the battery is sitting nice and tight and you are using them within the specs.

That NCM is more flammable than LFP is something we know all.

Not looking for discussion, really appreciate your comment. Just trying to understand it all to make a good decision between budget/price/safety.



Those I mentioned are also prismatic cells, same size as LFP cells.

so if you had already made up your mind, why ask ?
i wish you the best of luck, and hope to never find your home in the section "up in smoke" , which might be a good idea to take a real good look at

 

[Supervstech]

And to me it's the same for LFP. The only advantage of LFP is in overcharge event.
A short will cause a extremely rapid grow in temperature and can burn your place down.

A short will cause an extremely rapid grow in temperature (at cells or/and at short contact) and burn your place down.
An over current event can cause an extremely rapid grow in temperature (at cells) and can burn your place down.

To me, LFP cells should be considered as dangerous* than NCA or NMC chemistry or as a gallon of fuel, if you prefer, because they contain an important energy quantity who can be rapidly released.

*except that thermal runaway is way less probable.

LFP is no more dangerous than a stack of firewood.

The ONLY way LFP can catch fire is with overcurrent shorting and causing the wiring to fail in a red hot manner that starts a fire.
Yes, the electrolyte is flammable.
Yes, if there is a fire around the batteries, they will burn.
The batteries themselves do not cause a fire.

The solution to the cables getting red hot is FUSES...

if the wiring is setup so any overcurrent event causes a fuse to blow, and the wiring is sized to handle the fused current...
Safe.

NMC can erupt into a fireball on its own...
Battery internally shorts? Fireball.
Battery gets overcharged? Fireball.
Wiring issue causes a problem? You guessed it... Fireball...

Big difference.

Bottom line... no matter the settings, no matter the bms... parts fail. Have fuses to prevent shorts from causing a bad time...

 

[yabert]

let's agree to very much disagree.

Please don't be fool and don't play with the impressive fire out of low quality ''Li-Po'' cells. Let the others chemistry out of this thread.
Most EV battery in America and Europe are NMC or NCA. There is more and more LFP battery and it's a good thing to reduce stress on cobalt extraction.

 

[Nick0016]

so if you had already made up your mind, why ask ?
i wish you the best of luck, and hope to never find your home in the section "up in smoke" , which might be a good idea to take a real good look at

I have not made up my mind already, otherwise I would not start this thread... I did had plan for NMC yes but was still debating on the best choice hence this thread...

You only answer with "I do not want them in my home" or "it's dangerous" but no further explanation is not very helpful where as @Supervstech explains very well the difference and more the reason why to go for LFP.

 

[yabert]

LFP is no more dangerous than a stack of firewood.

Well... When I accidentally drop my wrench on a stack of firewood, I don't receive pieces of molten metal in my eyes/on my body
I think, for most people, LFP chemistry had been put in the box ''safe battery'' when all other chemistry are devil.
But most people don't realise, when they are in front of an inert LFP battery, that this chemistry can be really dangerous too.

 

[Supervstech]

Well... When I accidentally drop my wrench on a stack of firewood, I don't receive pieces of molten metal in my eyes/on my body
I think, for most people, LFP chemistry had been put in the box ''safe battery'' when all other chemistry are devil.
But most people don't realise, when they are in front of an inert LFP battery, that this chemistry can be really dangerous too.

...
Again, bad wiring practices cause lfp issues... not the lfp.

 

[dougbert]

I have not made up my mind already, otherwise I would not start this thread... I did had plan for NMC yes but was still debating on the best choice hence this thread...

You only answer with "I do not want them in my home" or "it's dangerous" but no further explanation is not very helpful where as @Supervstech explains very well the difference and more the reason why to go for LFP.

I went with Tesla modules but only after finding Jack Rickards Battery Management Controller, which uses Tesla own protocols on batter management and control. Here is the link to my research https://diysolarforum.com/threads/s...-to-xantrex-to-xw-pro-inverters.11/post-11810

Modules are now running $850 per module today, while when I started they were in the $1300 per range.

I do wish I had had the land to build a PowerHouse for it all, where I could heat it - I live in Utah at 5500 feet and it gets cold - away from the house. But I don't

Solar house generator I started DIY back in 2000 - My path from Trace to Xantrex (on FLA battery) to XW Pro inverters on Tesla Model S batteries

Holy cow thats awesome!!!!!

diysolarforum.com