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What does the i say that is attached to the term energy?

With 55% or less you can be sure that you will not wear out the battery. Most probably not with normal charging habits either. The batteri can develope other issues from the electronic parts etc, but i guess ypu will not wear it out. Melsomvik seems to have aroubd 9C average annual...

Its lower than average degradation, but about as expected counting your lower SOC after three years and the climate. The average cell temp is setting the degradation pace in the same way as SOC does. (But it is often not so easy to decide the ambient temp). I would guess - southern Norway...

Neither. It is the physics of the batteries. At low state of charge the battery can not deliver the same power as at high state of charge. So at the times you charge to a lower SOC to reduce the calendar aging you might get less power of the car.

For me, only one thing is important here on TMC - that people do their choices based on facts and not on myth’s that actually will render increased degradation when they try to reduce degradation. The choice made is 100% personal and as lithium batteries will not break by normal use as long as...

100% would be comparable to 70-95% for the 12hours. It is probably not a big difference between leaving it for 12 hours at 100% or leaving it at low SOC and then supercharge. Use the solution most convinient for you… Things not done every day will have a low impact on the total degradation...

Yes, Internal resistance is one of the things that causes less capacity, but it is already part of the measured losses we se at a calendar aging chart. So we do not need to account for ”extra capacity loss. Internal resistance will reduce the maximum power the battery can deliver and reduce...

Yes, like most of the general community ”knowledge” about lithium batteries it is a little divergent from the reality. 70% and below is good. (The ”step” at ~72% true SOC). Yup.

I have little older children, didn’t have the issue of stopping more often than the EV need charging but at *any* charging stop the car wins over the family :)

Low SOC and low SOC small cycles give the battery the possibility to recover capacity. After a series of superchargins etc, when using low SOC and cycling the battery in a nice way, the capacity will recover by returining part of the plated lithium to cyclable lithium.

There is an issue with that term. Deep discharge is a (for example) lead acid battery issue. They do not like to go below 50% SOC, and they wear a lot from low SOC. The *deep discharge* (as long as not below 0% real SOC) is not an issue for a lithium ion battery. We should extingt that term...

Thats completely safe. This test did run the cells (Panna ncr18650 like S/X) between 100% and the real 0% (below the Tesla buffer) and normal driving is around 0.2-0.3C so it means that the battery can do 750-800 full cycles until it has lost 25% (no calendar aging counted in that case...

We know that the batteries often starts being unpredictable above 20% degradation. The curves often goes south beyond. Using low power and low discharge rates can make cells work fine even when they passed 20% degradation but there is no guarantee they will. I see a risk of getting for example...

Its very ok to stay at 30%. I had my M3P with a two year average SOC of 35.4% (means a lot of time much below 30%, often single digit). The degradation after 2.5 years / 66000 km Was very low. Do you have a trsla with a panasonic battery? In that case 55% or below is better than 60%. The...

As Dr Chaos says. If people charged to 100% the possibly could not charge until they really needed to. This would mean large cycles with high Depth of Discharge. Below, Panasonic NCA (ncr18650) cycled between 100% and 0% (4.2V), 90% and 0% (4.1V) and 80% - 0% (4.0V). Look at the blue and...

Would be very interresting to se SMT hooked up to one of these cars.

Why would it be wrong? We know almost all types of lithium ion batteries have the lowest calendar aging at 0% SOC, but still we do not expect Tesla to recommend to charge to 0%. The range would be short… :-) Tesla of corse aim for a reasonable degradation leading to no or very few warranty...

The very close energy delivery between 3 LR and Y LR is pussling. Both the “close” part and the low delivered energy from the pack. Back to first type of Panna 2170 levels…

As you can see in the chart, 70/80/85/90/95% causes a higher capacity loss than 100%. This is not unusual. Long term storage or use at 100% will increase the internal resistance, so it is not recommended to always haventhe pack at 100%. Still, as 70-95% causes more degradation than 100%, the...

This is a research report I did not find before; searching for data about LG Chem 21700 M50. ( LG 78.8kWh pack). Might not be exactly the same cell as in the 78.8 pack but most probably close enough to paint the picture we need/want: So, now we have the data that tell us what we was reasonably...

So, for the EU Model 3/Y they use NMC811 (with a thad of aluminum). Se post above. That research report mainly research charging approaches connected to V2G but the real calendar aging and cyclic aging results tell us quite much: Despite that they only tested the cycles as 100% to 0% SOC...

So, this is actual test data for LG Chem 21700 M50 cells. Thats more or less the same as the E5LD/Y5LD in European terms, LG 78.8kWh pack that we now also see in US on 3LR ( and as I take it, also on Y LR). Can not guarantee that it is exactly the same as innthe cars, but it should be closely...

Nope, never checked. LG M48 is the cell called so would be google-able? 622 or 811, not ”older” due to the energy density I guess.

All Teslas historically used Panasonic NCA. Thats not NMC. All S/X still use NCA. Model 3/Y was NCA untill ~2021/2022 in rest of the world but continued with NCA in USA. The LG 78.8 is now used in USA as well for model 3 LR and as it seems also in the Y LR. The LG 78.8 (5L in European reg.)...

Well, it actually does not. Cyclic aging is very low for the most EV owners, like 0.5% degradation each year from cyclic aging. If you always went full throttle from 100% to 0%, there would be a significant reduction of capacity. Higher power increase the cyclic degradation but in general...

Dr Jeff seems to only talk stress and cycles, and seldom cover* anything else but the cyclic aging. Calendar aging causes a lot of degradation during the first 5-8 years of the battery life. In fact, cycling aging only causes a fraction of that for the most owners. Panasonic ncr18650 after 18...

Well, it actually does not. Cyclic aging is very low for the most EV owners, like 0.5% degradation each year from cyclic aging. If you always went full throttle from 100% to 0%, there would be a significant reduction of capacity. Higher power increase the cyclic degradation but in general...

Well, the reasons why we sometimes see the displayed SOC drop after a longer drive (or increase) is comming from the inability to correctly measure the SOC during the drive. -The BMS having an overestimate of the capacity leads to overestimated SOC, and a drop. And vice versa for a...

This is a recent drive. From 100-0% displayed we have more or less 1.0V, so 1000mV = 100%, and 10mV (0,01V) equals 1%. The drive started at 69% SOC and ended at 15%, so 54% used. The drive started at 3.93V and ended at 3.38V so 0.55V so we can see that the 1% = 0.01V is a good approx. You can...

That is a LFP / LiFePo4-battery with a flat voltage curve. OCV tested on a Pana NCA cell.

I do not se any variation, except if the car is out in the cold and the battery has cooled down, then the car deliberatly shows a lower SOC.

I have three year of logs from the BMS, showing this on two cars. Also, if one want proof, just read research about how batteries work. When my two Teslas had a underestimate of the capacity, the SOC always ended up below the set charging level, and the resulting SOC could be calculated from...

SOC is per definition a resting/ OCV Voltage. So while driving/charging you get a voltage droop / increase so you can not measure the SOC. The drooop/increase depends on to many factors to safely being able to be calculated. So having 3.65V OCV per cell or so at rest, the battery voltage might...

The BMS need to see the battery without any load before being able to judge the SOC precicely after a charge. I would guess that the junämp to 333 came at the time when the BMS had the data to update the capacity estimate. Probably quite short time after the charge was finished, and the door...

Yes, the LG has been known to start ”low” and increase the capacity during a couple of months or so (probably depending on theusage of the car). Often starts below 78.8 and ends at above 79 after a couple of months and then start the degradation (all according to the BMS numbers). While I...

It’s the LR witht the reduced EPA-range and the LG battery, right? 333 miles EPA-range, and a 78.8kWh LG battery. The 77.5kWh matches the cars I know about with the same battery that has used low SOC. Around 78kWh capacity after one year, but I think we have it slightly colder up here so 77.5...

I just saw some unconfirmed rumors (picture of a Tesla rep. Mail) where they said that the US version is actually more powerfull (500hp) vs the Europe version (460hp). This would mean that it will get the Panasonic more powerfull battery - if thats the case, good news for US. ;)

Yes, it is borh ways, slower charge and lower peak power output. But the cars are torque limited and do not produce 500hp from stillstanding. As power is = torque times rpm, we actually has close to 0Hp but a mot of torque when the car start. The power curve for the old M3P is increasing with...

The “stop” above 0% is not extremely uncommon. And it doesnt need to be a battery failure, it just need to be a bad capacity estimate. Think about how it can be possible for several cars to stop above 0% if the BMS could measure the SOC well during a drive. Tesla use 4.5% of the total...

I would not call it *think*… As you put a load on a battery, the voltage droops. The voltage droop vill vary with load, cell temp and SOC (internal resistance). It will also vary with the recent load history. There are too many variables to measure the drooped voltage and calculate the SOC from...

Electrolyte oxidation happens at very high voltage - in general above the maximum voltage lithium ion batteries use. 4.20V/cell is the 100% that Tesla use. The examples in Jeffs presentation is above 4.20V. I havent studied the electrolyte oxidation specifically but I would guess that this is...

After a drive, the displayed /calculated SOC will be updated with the measured (real) SOC*. If the SOC seems to ”drain” after a drive when the car is sleeping (not using Sentry or heat etc.) the reason is that the real SOC was lower than the calculated SOC, and the reason is most often due to...

You already have some data about the increased degradation in post 209.

Yes, I think so. When I had my M3P And had the car wirth low SOC at work and had to charge fro the long drive home I initially went to a in town 25kW DC charger as Tesla heats the battery at any DC charger. I waited until the cell temp was 45C or so, then I went to the local 200kW charger (no...

In the garage, probably best to renove from bike if easy to ensure the bike do not draw it empty. Let it warm before charging. Lithium batteries should not be charged when the cells are sub freezing so best to let it acclimatize to room temp first.

Nope. The 100% is refering to feeding the cells with 4.20V each until the current is below a certain limit (think - untill current stops) A degraded battery will be able to charge to 100% but the energy it delivers will be less. Degradation refers to delivered energy (or in some cases...

I tried ~50% until I needed more each day. Smaller cycles is good so charge when driving the car and so on. Cold is good. Temperature has the same effect as SOC, so… If you put a cell in a plastic bag and that bag in the freezer, the air inside the bag contains moisture that will fall out as...

Tesla tell us that the frequency of supercharging can affect range in the manual and online: From tesla.com: From my S manual: (In swedish, I didnt care to download a english version, but in short it states the same as on tesla.com) So, I find it strange that Tesla would spread myths. The...

I wouldnt be so sure about that. I would say that there is only a few studies that think they found no degradation from fast charging. Fast charging wears on the batteries. But normal amount of supercharging is not a problem.

No, theres no damage coming with low SOC. That is a myth. Just as the myth that 100% should be very bad. It is not. As for the myths, theres is no research supporting the myths (that’s why I call them myths). If you actively search for real facts for these myths, you will not find anything...