Do i have to keep it plugged in everyday?

[gtg465x]

Yes, thats true.

I know that I could use a more agressive approach myself than I actually would dare to tell, of I had a LFP Tesla and did drive very little.

Giving advice to *anyone* ( = that might miss a few important things, and then get stranded and mot happy) probably need to be adjusted to be “safe” when it comes to the actual range vs displayed.

One issue is not knowing the details of the LFP cars. I have a collegur that ordered a Y LFP so I will do some SMT checkups to learn.

Do tell your aggressive approach! I have 2023 3 RWD. Had it since December and only have 1843 miles on it… averaging 88 miles per week (although probably more like 70 if you exclude one 350 mile day trip). I do not charge to 100% once per week as Tesla advises. I have charged to 100% 7 times in 21 weeks, so about once every 3 weeks, typically right before a drive that will at least use 15% (although it still usually takes me a few days to get it back below 70%).

 

[AAKEE]

Do tell your aggressive approach! I have 2023 3 RWD. Had it since December and only have 1843 miles on it… averaging 88 miles per week (although probably more like 70 if you exclude one 350 mile day trip). I do not charge to 100% once per week as Tesla advises. I have charged to 100% 7 times in 21 weeks, so about once every 3 weeks, typically right before a drive that will at least use 15% (although it still usually takes me a few days to get it back below 70%).

I would charge late (just ready for the next days drive) to 50-60% daily.
I would only charge higher than 70% when needed and in these cases always to 100% (no 70-90%) which is about once or twice a month normally.
Of course charge as late as possible* for the 100% charges, and with max AC charging speed (11kW).

The 50-55% is chosen to give a margin upwards above 70%. Inceased buffer to 10-12% means that the true SOC will be further higher compared to the displayed SOC.
Also a unsafe SOC situation probably could end up with having the real SOC higher than displayed as well as lower.
A charge to 60% displayed could be offset by 5% to 65% (from increased buffer) and at the real SOC could be higher due to unsafe SOC estimation. So end charge displaying 60-70% could mean 80% true SOC.

*) We can se that calendar aging ‘eats more’ at 70-90% than at 100%. This is valid for the first 6 months at 100% so we probably will have this behaviour for a long time (always?) as each charging session above 70% until driven down below 70% is only a few hours.
We can also see that 100% does’nt cost much more than at 70% so it is not a big deal to leave it at 100%.

 

[STS-134]

*) We can se that calendar aging ‘eats more’ at 70-90% than at 100%. This is valid for the first 6 months at 100% so we probably will have this behaviour for a long time (always?) as each charging session above 70% until driven down below 70% is only a few hours.
We can also see that 100% does’nt cost much more than at 70% so it is not a big deal to leave it at 100%.

You sure about that? It looks like for 50°C/9.3 months, the local maximum in degradation around 80% is gone, and it's monotonically increasing after 70%. Who knows what happens after say 12 months or 18 months, or at 25°C for 50 months, etc.?

 

[Iron]

You sure about that? It looks like for 50°C/9.3 months, the local maximum in degradation around 80% is gone, and it's monotonically increasing after 70%. Who knows what happens after say 12 months or 18 months, or at 25°C for 50 months, etc.?

What is your aggressive charging method for LR vehicles with 2170 batteries? Sorry if I'm making u repeat, I'm sure you've stated it somewhere I've not read.

 

[STS-134]

What is your aggressive charging method for LR vehicles with 2170 batteries? Sorry if I'm making u repeat, I'm sure you've stated it somewhere I've not read.

- Set charge limit as low as possible or to 50%
- Charge only as much as needed on any given trip, +10-20%, if you need > 50%
- Scheduled Departure set for 30 minutes-1 hour prior to departure
- Only charge to 100% once every 3-4 months, and only just before consuming at least 30-40% battery in a single day

 

[Iron]

- Set charge limit as low as possible or to 50%
- Charge only as much as needed on any given trip, +10-20%, if you need > 50%
- Scheduled Departure set for 30 minutes-1 hour prior to departure
- Only charge to 100% once every 3-4 months, and only just before consuming at least 30-40% battery in a single day

Thanks. My question was also meant for AAKEE. I've read repeatedly that you should never charge to 100% if avoidable. Unless you're on a long road trip and avoid it even then because of the hit to the battery, the charging slows drastically leading up to it and there is no space for regen energy, which makes it inefficient (although on a long trip you're not braking and the small amount of depletion needed for regen happens quickly on the highway). Currently I'm charging to 75% and daily RT commute uses roughly 15-20%. Guess I could go lower. I haven't gone below 50% in 3 months and have only been there once.

Bought a used 2020 M3P this past Monday but waiting for title to arrive so i can register car. Do i have to keep it plugged in everyday or can it just sit till i can go to DMV? its currently at 73% charged.

OP, yes you can and should plug it in everyday. I say this because plugging in does not necessarily mean charging. The app or touchscreen controls that and without it plugged in, you cannot control it remotely. There are times plans come up when you're away from home and you'll need that car charged when you arrive.... so it's more about the ability to have instant control at your fingertips.

So don't control charging by plugging/unplugging. Charge it via charge limit, scheduled departure, off peak charging, etc etc.

 

[AAKEE]

You sure about that? It looks like for 50°C/9.3 months, the local maximum in degradation around 80% is gone, and it's monotonically increasing after 70%. Who knows what happens after say 12 months or 18 months, or at 25°C for 50 months, etc.?

That’s not sure in as very sure, but reading the research and what drives calendar aging and how it happens, it would be a fair guess that it will be the accumulated amount of degradation processes that set the rate of degradation.

Im not currently at home, so my biblio of reports isnt available. Didnt find the correct report for references…but:

At low SOC we have mainly anodic side reactions.

Consequently, solely anodic side reactions are the predominant aging mechanism at low SoC. These side reactions, which are related to electrolyte reduction and SEI growth, are known to cause right-shifts of the discharging endpoints and this agrees well with the observed transformations of the charging curves.

At high SOC we have also cathodic side reactions.

Side reactions at very high SoC.—In addition to the slippage of the discharging end point, Figures 10d–10f show the slippage of the charging end point. It is moderate or small for storage SoCs up to 80%. For storage at 100% SoC, however, increased shifts of the charging endpoints are observed at all temperatures. This indicates aggravating cathodic side reactions. As described above, there are also larger shifts of the discharging endpoints for storage at 100% SoC. This supports the assumption of coupled side reactions, e.g., from transition metal dissolution at the cathode and a reduction of the dissolved transition metal ions at the anode.

If we mainly stay low we started ”burning the high side”, so the cathodic reactions havent happened.
If we only use high SOC for short times it will take very long time to accumulate the 6 months when we still have lower calendar aging at 100% than at 80-90%.

My own tests with 35 pieces of 2170 support this.
There is still higher degradation at 80% than at 100%, and these cells have been at 100% for 3months (at 10C) as the first test.
The cells are now 1 years and 4 mounths since I did get them. I have no data om the manufacturing date.
Last checkup was in february, and the latest three month calendar aging was higher on the once at 80% then the onces at 100%.

For 2170, this test show that this continues at even one year. We do not know the brand of these cells, but there isnt many 2170 NCA manufacturers.