-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Model 3 SR+ LFP Battery Range, Degradation, etc Discussion
- Thread starter Baluchi
- Start date
LFP is much less sensitive to large cycles / high DoD.
If you constantly use 100-0% cycles you still will have 3000-5000 cycles before the LFP have lost 20% capacity.
3000 cycles will be close to 1 million km or 600.000 miles.
The cyclic degradation will not be the dominant degradation suring the first 3-5 years.
Calendar aging is the dominant degradator and is less with low SOC.
Nezz
Member
mkrbris has an interesting take that I haven't heard of before. Did some digging into research and here's an interesting finding.
There are 2 topics I'm looking at right now. 1. Depth-of-discharge and 2. Temperature Impact.
Here's a good finding, although these LFPs were considered "Graphite", "Sauer at al. reported that cycling degradation at 1C between 45% and 55% SOC was greater than between 50% and 100% depth-of-discharge (DOD)"
On the 2nd topic, it seems that LFPs are way more sensitive than I thought to high temperatures when considering degradation.
www.sciencedirect.com
There are 2 topics I'm looking at right now. 1. Depth-of-discharge and 2. Temperature Impact.
Here's a good finding, although these LFPs were considered "Graphite", "Sauer at al. reported that cycling degradation at 1C between 45% and 55% SOC was greater than between 50% and 100% depth-of-discharge (DOD)"
On the 2nd topic, it seems that LFPs are way more sensitive than I thought to high temperatures when considering degradation.
Insights for understanding multiscale degradation of LiFePO4 cathodes
Lithium-ion batteries (LIBs) based on olivine LiFePO4 (LFP) offer long cycle/calendar life and good safety, making them one of the dominant batteries …
www.sciencedirect.com
jackmott
Member
The question is which will have less net overall degradation. A car going between 50 and 100% will have more age based degradation than the one going between 45 and 55. Unless you are just doing nothing but driving and charging all day every day. They report that age based degradation was 10-30% of degradation during their tests, but was that a test where it was constantly cycled?
Last edited:
OK that was posted April 10, and so I went around 3 months keeping the SOC between 30% and 74%. Today I charged all the way to 100% and the projected range at 100% was 245 miles. That would be an 8-mile loss (slightly more than 3%) from 10 months ago when the car purchased. 5300 miles on the car and the life time watt hours per mile currently sits at 229.
Interesting so i think it is better to charge it 100% all the time i guess. I wonder if keeping it at 100% soc if not driven same day will have any negative impact or battery degradation.
thebestiam1
Member
11,000 miles and mine is also showing 245 miles @ 100%. Was originally 253 miles when I first got the car. Is there any way to regain that 8 miles back?
Last edited:
Same question here. I tried an uneducated simulation of something I read in the sticky thread they have where an owner was repeatedly running his battery down to a single digit SOC, then letting the car sleep (and, I believe, allowing the car’s battery management system to re-evaluate its batteries). Apparently he did get quite a bit of his range back by doing that. But I got the car down to 5% charge yesterday, powered it down for 5 minutes, then left it sitting/sleeping for about 5 hours in the garage, before charging it up to 100%. For the past few months charging the car to 74%, it always stopped charging at 181 miles, and 181 miles is 74% of 245 miles. So all my uneducated efforts had zero effect on the projected mileage. I’ve pretty much resigned myself to the prospect that I won’t be seeing those lost 8 miles ever again…
jackmott
Member
Batteries lose range with time. All you can do to nearly stop it is park the car at 1% charge in a freezer and never drive it.
My guess is yes, it would have negative impact, but to some potentially negligible degree like the car lasts only 12 years instead of 13, or something like that…
Tesla recommends charging 100% at least once a week with LFP batteries which I believe is for BMS calibration due to LFP cells having a relatively constant voltage. With this in mind, to reduce degradation on the battery, would it be best to charge to say 70% daily then set it to 100% once a week and drive shortly after, or what would be the best charging practice to have the battery live the longest life possible?
Tesla recommends charging 100% at least once a week with LFP batteries which I believe is for BMS calibration due to LFP cells having a relatively constant voltage. With this in mind, to reduce degradation on the battery, would it be best to charge to say 70% daily then set it to 100% once a week and drive shortly after, or what would be the best charging practice to have the battery live the longest life possible?
There are probably a few things to consider if you are concerned about minimizing degradation:
- Set charging to finish shortly before you drive off, particularly if charging to 100%. This is to minimize time parked at high state-of-charge.
- Charge normally to some level lower than 100% (preferably under 70% for LFP batteries, under 55% for NCA batteries based on the recently posted image), but charge to 100% only occasionally (once per week for LFP batteries; only when needed for NCA batteries).
- Charge frequently so that each charging session is smaller.
- When parking the car for longer periods of time, prefer having it in the lower state-of-charge range (but not so low that vampire drain will drop it to 0%).
- For longer term storage (where the vampire drain is more likely to drop it to 0% if unplugged), it may be best to plug it in with the charge target set to 50% (the lowest setting). For LFP batteries, charge up to 100% just before driving the car again to ensure that the BMS is correct.
AlanSubie4Life
Efficiency Obsessed Member
Yes, this is a good idea since it keeps depth of discharge to a minimum which is good for all Tesla batteries. It also makes plugging in a habit which is desirable to ensure your car is always sufficiently charged. Bonus: recommended by Tesla.
Based on what he said above, probably he does not actually do this. There are various reasons why an owner would not.
No, because I do not drive every day. I plug in the afternoon or evening before I need to drive enough that I want the car to be "full" at the beginning of the day.
A reasonable alternative would be the set the charge limit to 70% and plug in whenever parked at home, but remember to set the charge limit to 100% once per week or so, using scheduled time to finish just before driving off.
gergelyricsike
Member
Similar threads
