How is my LFP battery holding up after 2 years?

[Ivan Ivanov]

I think 54kw should dispay 448km and 60kw should be 491km as new. This information is from auto-data.net

 

[kelvin 660]

Those figures you are quoting @Ivan Ivanov are WLTP, however the car displays EPA. So 448km WLTP (278 miles shows as 423km EPA (263 miles) on the cars display, when the car is new.

 

[stioc]

So, my battery capacity has degraded by 51.46 ÷ 53.97 = 0.953 or 4.65% (or 2.33%/year). This result is also confirmed by TeslaFi’s Battery Degradation Report attached.

Nice, thanks for sharing the data @kelvin 660 . However, as a new LFP M3SR owner I'm also curious what your charging habits have been? Are you following Tesla's recommendation for charging daily and at least 100% once a week?

 

[RichAZ/CapeCod]

M3 SR RWD, picked up 8/29/22, 7,500 miles now; 100% SoC=273 miles indicated when new

Oct 20, 2023, after sitting six months at 50% SoC, when at 100% SoC=264 miles indicated

Rich

 

[xreyuk]

M3 RWD received 20th Feb with delivery mileage - 273 miles at 100% SoC

As of today, 9700 miles (ish), after charging to 100% every time I charge it (around once every 5 days or so) - 267 miles at 100% SoC

Tessie reports bang on 2.0% battery degradation from new, based off its kWh measurement, mileage displayed would be around 2.2%.

 

[kelvin 660]

Nice, thanks for sharing the data @kelvin 660 . However, as a new LFP M3SR owner I'm also curious what your charging habits have been? Are you following Tesla's recommendation for charging daily and at least 100% once a week?

Since Jan I'm on IO and normally fully charge to 100% every 4 to 5 days. Before I was on GO and charged every 3 to 4 I never let it sit at 100% for more than 4 hours.

My latest battery report.

 

[nicksp]

Not LFP, but our Model 3 LR is reporting 296 miles vs 310 miles from new. That’s under 5% in 30k miles.

However, tbh, it’s been all over the shop over the years and I take the so called reported mileage’s calculated by whatever method with a large pinch of salt.

View attachment 980963

So what’s changed? Combination of events. Couple of firmware update issues (confirmed by Tesla, leading to), Tesla resetting the CAC (ie resetting BMS) and possibly a change in charging regime where since moving to IO, we allow the battery SoC to drop more before charging. It use to be little and often, now it’s a bit more of a charge and less often.

But I’m expecting it all to go south over winter again. Last winters dip coincided perfectly with winter tyre change.

But these values are more about how good a job the BMS does at guessing/estimating the stored capacity than anything concrete about battery degradation. And as I understand it, getting within 10% of true value is pretty good going.

I thought with the range increase to 325 miles, that should be where you start the degradation calculation. I was asking the question in another thread also if older M3LR all got the range update to 325 miles. I have a 18 M3LR abs at 100% showed 300 miles today.

 

[Msaman]

Guys just a quick question.
I picked up a second hand M3 LFP 60kw with 20k miles 72plate.
Tessie shows me that my usable capacity is 57.4 and gives me degradation of 4.5%.
My full charge is 263 miles out of 278 when new.
Which one is true.
I thought the usable capacity has always been 57.5kwh?
I really think these batteries either are affected by calendar ageing only or are software programmed to display that range.
How can I check the original net capacity?

 

[Adopado]

Guys just a quick question.
I picked up a second hand M3 LFP 60kw with 20k miles 72plate.
Tessie shows me that my usable capacity is 57.4 and gives me degradation of 4.5%.
My full charge is 263 miles out of 278 when new.
Which one is true.
I thought the usable capacity has always been 57.5kwh?
I really think these batteries either are affected by calendar ageing only or are software programmed to display that range.
How can I check the original net capacity?

Unless you have the data from new it’s a problem to really know the degradation. The mismatch between the capacity reduction and the “range” reduction is something that I see with Tessie as well. Unfortunately I don’t have my original numbers either as I only started using Tessie in late 2022 though the car is from 2019 (not LFP).

 

[GeorgeSymonds]

Guys just a quick question.
I picked up a second hand M3 LFP 60kw with 20k miles 72plate.
Tessie shows me that my usable capacity is 57.4 and gives me degradation of 4.5%.
My full charge is 263 miles out of 278 when new.
Which one is true.
I thought the usable capacity has always been 57.5kwh?
I really think these batteries either are affected by calendar ageing only or are software programmed to display that range.
How can I check the original net capacity?

Tessie won’t be right unless it gets lucky. It is extrapolating rounded numbers to try and come up with a figure.

The best indication of this (and any of the 3rd parties who do similar) is to look at a degradation line over time for a given car, they’re generally all over the place going up and down.

 

[kelvin 660]

Guys just a quick question.
I picked up a second hand M3 LFP 60kw with 20k miles 72plate.
Tessie shows me that my usable capacity is 57.4 and gives me degradation of 4.5%.
My full charge is 263 miles out of 278 when new.
Which one is true.
I thought the usable capacity has always been 57.5kwh?
I really think these batteries either are affected by calendar ageing only or are software programmed to display that range.
How can I check the original net capacity?

One way of finding out the battery capacity is to use this method,

Calculating Your Battery's Estimated Capacity Using the Car's Energy Screen

Re posting here and making this a sticky post so it doesnt get lost. @AlanSubie4Life originally posted: =========================================== (originally posted by @AlanSubie4Life. Original thread this appeared in can be found here: ( 2021 model Y scan my Tesla battery size)...

teslamotorsclub.com

In my case, I started with 54 kWh (not the claimed 55 kWh) when actually 1 week old and is now siting at 51.45 kWh, giving a battery degradation of 4.72%. This figure compares with 263 miles range at 100% SoC when new, and now siting at 250.65 miles at 100%, (after 2.25 years and 22,800 miles) giving a battery degradation of 4.695%. So both methods appear to give similar results...

Note: Scan my Tesla reports my car as having a 55.1 kWh battery when new, but I never saw it at that level! However, when I compare the energy screen method with SmT method I get the almost identical results over the life of my car.

In your case @Msaman your 100% mileage figures give a battery degradation of 5.39%. However, I think when new you car only charged to around 273 miles at 100% SoC. Using that figure your battery degradation would be in the region of 3.7% and in normal range for a car of its age and mileage. Data obtained from here: Degradation using M3 SR+ LFP 2010

 

[Msaman]

Thanks guys.
I'm doing Uber so plenty of chance to run it from 100% to almost zero ;*)
Efficiency in London the last few days 180-190 wh/m at 10-12C.
Not really bothered by degradation but was really curious to know the numbers.
Merry Christmas everyone.

 

[RichAZ/CapeCod]

Another LFP data point:

Kyle Connor picked up a new Coda EV, with LFP battery. Been sitting in the sun for more than a decade at the dealers lot, yet had 30% charge in the main battery when tested! Car is being "reborn" by Kyle so more details will be coming.

Looks to me like these LFP chemistry batteries will last a looong time...

Rich

 

[Msaman]

Fingers crossed as I'm putting close to 180-200mls a day ;*)
Just did a 400 miles journey from London to Leeds and the car returned 192wh/ml at 60+ mph. Temperature outsid 7C.
So efficient with heated seat and steering and the fans at 18C ;*)
Love the car, I just need some noise insulation but there are no perfect things in life.

 

[Patrick_TX]

Fingers crossed as I'm putting close to 180-200mls a day ;*)
Just did a 400 miles journey from London to Leeds and the car returned 192wh/ml at 60+ mph. Temperature outsid 7C.
So efficient with heated seat and steering and the fans at 18C ;*)
Love the car, I just need some noise insulation but there are no perfect things in life.

Have had my M3 about 3 weeks and I'm seeing some DIY noise dampening projects in my future...

 

[kelvin 660]

Fingers crossed as I'm putting close to 180-200mls a day ;*)
Just did a 400 miles journey from London to Leeds and the car returned 192wh/ml at 60+ mph. Temperature outsid 7C.
So efficient with heated seat and steering and the fans at 18C ;*)
Love the car, I just need some noise insulation but there are no perfect things in life.

I've been following this car, as its the same age as mine but it has done a lot more miles (144,133 miles) and its degridation is almost the same as mine!

This mileage works out around 180 miles/day, so @Msaman I think you should be OK.

I assume it must be a taxi to do such high mileage...

 

[Msaman]

Yup. That's my 3rd month as private hire driver. Tried Kia for 2 months initially and the last two weeks or so been in the Tesla. Night and day difference in charging speed when the battery is preheated ;*))) and amazing efficiency with AC and motorway speeds. Has anyone done the double insulation on the doors?
Also I think the majority of the noise comes from the boot which should be relatively easily to insulate.
Have a nice week guys.

 

[kelvin 660]

Finally, the 100% SoC range has leveled out on my car. This levelling out started when the car was around 24 month old.
Initially, my battery looked better than most and now looks to be one of the worst! Still it's only a few miles difference so I'm not worried...

@Msaman When I've had my boot loaded with luggage, etc. the car has been much quieter as it reduces the road/tyre noise so that's a good place to start...

 

[Msaman]

So after some calculations using the expected range and the efficiency method the battery comes to 58kwh. Installed Scan my Tesla as well and it's reported as 58kwh usable plus 2.5kwh buffer.
The question is why doesn't it show it has 273 miles then if virtually has no degradation.
Thanks Kelvin60 I will certainly start from the boot just waiting for the weather to warm up a bit ;*)
Before that, I will be certainly getting a set of Hankook Ion Evos tyres.

 

[kelvin 660]

Installed Scan my Tesla as well and it's reported as 58kwh usable plus 2.5kwh buffer.

Your doing the calculation wrong. It's not 58kWh plus 2.5kWh buffer. Your car started with something like 60.1kWh when new (check SmT for acurate value) and you now have a 58kWh battery (this includes the 2.5kWh buffer), so you have lost about 3.6% of your battery.