0% SoC

[Macadoodle]

LFP have 100% depth of discharge with out degredation

From what I can gather, LFP cells are certainly much more tolerant of full use of their capacity, but will still last longer if you use less.
I tend to call a halt at 10 % and try to burn some off within a few hours of a 100% balance charge.
I dunno, maybe it's unnecessary but I don't want to lose much capacity over the years I own it as 50kWh is about the least I can live with

 

[Cocijo]

It’s also very interesting that the BMS for LFP needs to be specific to that technology. I’ve seen a few posts about irrational power delivery and your comments about weather impact and the need for specific BMS management of the energy discharge could have some relevance here.

 

[Ayoull]

It’s also very interesting that the BMS for LFP needs to be specific to that technology. I’ve seen a few posts about irrational power delivery and your comments about weather impact and the need for specific BMS management of the energy discharge could have some relevance here.

It's not so much the weather that was a bad choice of words it's the ambient temp and battery pack temp it needs to take into account.

You could have voltage collapse underload which would cause the car to throttle performance but I'd expect the turtle mode to activate as the BMS would show it as low SOC.

From what I can gather, LFP cells are certainly much more tolerant of full use of their capacity, but will still last longer if you use less.
I tend to call a halt at 10 % and try to burn some off within a few hours of a 100% balance charge.
I dunno, maybe it's unnecessary but I don't want to lose much capacity over the years I own it as 50kWh is about the least I can live with

LFP cells are rated for a minimum of 2000 cycles but most CATL cells have been shown to last 5000-10000 cycles in stress testing.

NMC and NCA are only good for 1000 full cycles hence the need to keep them between 20-80% you're basically only doing just over half a charge.

Also most things last longer if you don't use them, if I don't have ketchup with every meal I'll still have a full bottle at the end of the year but won't have enriched my life ?

Thanks. Great info. Don’t CATL supply SAIC?

Sorry missed this, I know CATL supply the NMC cells not sure who supplies the LFP ones

Also worth noting that your useable kWh rating Vs pack size is a good indication of the levels of degredation expected.

SR LFP 50.8:51.0 = 99.61% usable 0.39% buffer
LR NMC 61.7:64.0 = 96.41% usable 3.59% buffer

And the buffer is there to help account for cells not liking being floated at 100%, some voltage discrepancy prior to balancing and degredation.

 

[Macadoodle]

Thanks. Great info. Don’t CATL supply SAIC?

Almost certain CATL supply the LFP and its a cell to pack config, main reason I went for the SE SR.

LFP cells are rated for a minimum of 2000 cycles but most CATL cells have been shown to last 5000-10000 cycles in stress testing.

NMC and NCA are only good for 1000 full cycles hence the need to keep them between 20-80% you're basically only doing just over half a charge.

Also most things last longer if you don't use them, if I don't have ketchup with every meal I'll still have a full bottle at the end of the year but won't have enriched my life ?

I do like ketchup. You're probably right, not worth worrying about. 10% is my minimum comfort zone so that will be done anyway but as I just plug it in in the evening and forget about it, it's easy to let it bump up to 100% without noticing.
There's not much energy in the last 5% so it's a pity there's not an option to tailor your charging in 5% increments.

 

[Cocijo]

Also worth noting that your useable kWh rating Vs pack size is a good indication of the levels of degredation expected.

SR LFP 50.8:51.0 = 99.61% usable 0.39% buffer
LR NMC 61.7:64.0 = 96.41% usable 3.59% buffer

And the buffer is there to help account for cells not liking being floated at 100%, some voltage discrepancy prior to balancing and degredation.

Another great bit of information - thank you. So, generally speaking the larger the % buffer the higher the expected degradation.

Almost certain CATL supply the LFP and its a cell to pack config, main reason I went for the SE SR.

I do like ketchup. You're probably right, not worth worrying about. 10% is my minimum comfort zone so that will be done anyway but as I just plug it in in the evening and forget about it, it's easy to let it bump up to 100% without noticing.
There's not much energy in the last 5% so it's a pity there's not an option in 5% increments to tailor your charging.

I prefer Daddies, but will take ketchup mostly on chips.

 

[Ayoull]

Another great bit of information - thank you. So, generally speaking the larger the % buffer the higher the expected degradation.

Roughly speaking yes, but it's manufacturer specific on BMS and Battery manufacturer but on the 4 atleast there's expected to be almost 10x the degredation of charged to 100% with NMC in comparison to LFP.

But don't be alarmed if you have a NMC pack we have a MG ZS EV MK1 with 46k on clock always charged to 100% lowest it's been is 8% and still showed 98.7% State of health at it's service and first MOT in November.

 

[siteguru]

You do know that you don’t have to read every Single thread on here don’t you?

To be fair, he did start this thread.

 

[Ayoull]

To be fair, he did start this thread.

Missed the handbags at 20 paces earlier in the thread I was too engrossed in technical shizzle ??

 

[Cocijo]

To be fair, he did start this thread.

You need to take my reply in context to what I was asked (see post#10), not as a single sentence.
OP’s don’t own threads - yes it’s good to try to stay on topic, but if it doesn’t go the way the OP believes that it should, well too bad, we all have experienced it, it’s how a forum works.
Nearly all my threads as OP seldom take the direction that I expected.
We have moderators that decide on that type of thing too.
The very nature of the subject matter on this thread means it can morph into something more technical.
And it’s turned into a really useful thread in my opinion. ?