It is worth being aware of cell balancing too. If the car’s BMS does passive cell balancing, as is most common, this means charging to 100% and leaving it charging until the charge point indicates that it is no longer drawing any current. This is one reason why car manuals recommend charging to 100% occasionally. I bought an OBD-II adaptor so I can look at the individual cell voltages and see when they are starting to drift apart, and only do the cell balancing charge at that point. E.g if the cell voltages vary by 0.02V or more. So I hope this will let me play the game of extending my car’s battery life as long as possible.
I don’t normally drive much or need the range except for road trips…. I have an LFP battery Model 3 RWD…. I still set to max 50% during the week as it may sit there for days and doesn’t need more. Once a week it’s set to go to 100% to get BMS updated. Before a road trip I have it go to 100% during the night so it’s ready in the morning. Same at hotels if driving on road trips, go to 100.
Another useful trick. When you do need to charge to 100%, you can use the car's "delayed charging" feature so the battery doesn't actually hit 100% until right before it's time to leave. This minimizes the amount of time that the car needs to sit around, idle, with a full charge. Just be sure to shut off delayed charging when you do leave so that it doesn't interfere with public charging during the trip.
The video states that charging to 100% regularly will degrade the battery quickly. Please be clear what is meant by degrading quickly. If I keep my car charged between 30% and 70% does that mean my batteries will last something like 8 years but charging to 100% constantly it will only last 5 years? A difference of weeks or months in battery life time could be considered insignificant but degrading years faster would be a big difference. I think that’s the data people want and need, not just general statements like degrade quickly. If real world data exists giving people actual numbers drives the point home a lot harder than general statements.
Your guessed numbers are not too far off. Half the aging is what is being seen in the wild when owners charge to just 50%, etc. Comparing to 100% isn't great tho because there are other issues that might come into play besides just pack degradation if you stay at 100% regularly. Basically set the lowest possible limit that is comfortable for your daily driving. Raise the limit immediately before longer trips.
After watching a recent presentation that Kyle shared I am going to focus on setting the limit to 70% and try to keep it in the 70-45% SOC. Then if in storage keep it at 30%. The presentation was really good and showed the data from torture testing and results. I used to use the 80-20 rule. 80% SOC limit and keep it above 20% on the bottom, but the presentation makes the argument that less discharge shorter cycles is better. Of course that is for regular Lithium ion batteries.
@@Dactylonian Here is the summary from The Limiting Factor and the link to the now private video. How to look after your Long Range Tesla Battery! Advice from Jeff Dahn, who's lab is partnered with @Tesla : ruclips.net/video/mN91pS1hSSQ/видео.html The key takeways of this video are: 1) Jeff's advice in the video only applies to high nickel batteries in long range vehicles! Not LFP standard range vehicles. 2) High temperatures kill batteries. If you go on a holiday/vacation during the summer, leave your vehicle at a low SOC (state of charge). For example: At or below 30% SOC 3) Cycle within a narrow SOC range. For example: 40-60% rather than 10-80%. The cathode expands and contracts in a wider SOC range, which causes it to break apart. 4) On that note: The lower the narrower the SOC range, the better. That means charging frequently. 5) Avoid charging the vehicle above 75% SOC. Above 75% side reactions start occuring that cause degradation. This also reduces the volume expansion issues mentioned in 3). 6) Taking all variables into account, operating between 45-70% SOC and storage at ~30% is ideal. 7) Occasional high SOC and wide SOC range are okay! For example, the occasional roadtrip. 8) With good thermal management hardware and battery managment software, supercharging should have minimal negative effect on cycle life. Watch the video if you'd like more specifics! ruclips.net/video/mN91pS1hSSQ/видео.html It's worth watching because Jeff Dahn is one of the fathers of the Lithium Ion battery and his lab is partnered with Tesla.
Charging to 50-60% has less than half the degradation than at 80%. Its no wonder Kyle chooses that path. At 50%, a Model 3 has 125 miles of range which is more than enough to meet daily needs (typically). If you can charge at home every night, its probably the best charging habit. If you are using public chargers, then I can see charging to 80% so you aren't constantly looking for chargers. In the end, do whats convenient for you to enjoy the car.
I would say “Read the owner’s manual” - my car, not an LFP Tesla but a Mini Cooper S E, advises to let the car charge to 100% every time as it has a sophisticated BMS to look after the battery health. It only charges its 28.9 kWh battery at up to 50kW though. In the Mini there is no way to set an upper charge limit.
That’s fine, but make sure 100% once a week minimum when you’re using it to ensure it’s guessing the battery % correctly. Overall we don’t know enough about LFP degradation with Tesla’s latest BMS so it’s best to follow their advice - you won’t hurt it charging to 80% the rest of the time.
You should if you want to maximize battery life, but my personal view is 90% will make for a marginal difference - so if the range on tap is valuable to you don’t stress too much about having it at 90%! I leave mine at 80% when possible.
Alternatively, look at the battery warranty and purposely degrade the battery within the warranty period so you actually get a useful life out of your vehicle with 2 batteries.
I don't think this would work. The battery degradation threshold needed to trigger a warranty replacement is very high, and modern batteries last a long time. Even if charged to 100% all the time and used fast chargers for all of your daily driving, you still likely wouldn't be able to degrade it fast enough, at least with normal driving. I suppose if you really wanted to, you could choose to spend your entire day every day fast-charging the car to 100%, driving it down to 0%, and repeating, and maybe then you could trigger it. But even that wouldn't work because the battery warranty has a mileage limit, as well as a time limit. And even if it did work, you'd be wasting so much time degrading the battery, it wouldn't be worth it anymore - you'd do better financially by spending those hours working a job, instead.
However, certain manufacturers like the Hyundai/Kia/Genesis EGMP products have a built in "pad" with their battery packs that won't allow you to charge above the "usable" amount, nor discharge below a certain amount. As such, when using my home level 2 charge station, I routinely charge my EV6 to 100%, as it recommends to charge to 100% at least once a month in the car's manual. Charge discharge cycles also add to battery degradation, so the more often you have to charge using a narrower charge window (say 30% to 70%), the more degradation you'll get. When you purposely limit your charge to 80%, you have to charge more often per month. I honestly think that with the battery management systems in modern EVs (those that have come out over the past few years), that limiting the charge to 80% when level 2 charging isn't a factor anymore. To be clear, I'm not saying to routinely charge to 100% when using a DC Fast charger, but at home for most of us on a level 2, exceeding 80% isn't going to cause long term issues. For long term sitting (routinely over a week), I agree with the 40% - 60% charge recommendation.
You are misunderstanding charge cycles a bit. Each time you charge doesn't count as a full cycle. If you charge from 70 to 80 that only counts as a tenth of a cycle. So doing more shallower charges isn't an issue, it still adds up to the same amount of cycles in the end. Full charging once a month is good, but I wouldn't do more than that unless you need the range.
It is worth being aware of cell balancing too. If the car’s BMS does passive cell balancing, as is most common, this means charging to 100% and leaving it charging until the charge point indicates that it is no longer drawing any current. This is one reason why car manuals recommend charging to 100% occasionally. I bought an OBD-II adaptor so I can look at the individual cell voltages and see when they are starting to drift apart, and only do the cell balancing charge at that point. E.g if the cell voltages vary by 0.02V or more. So I hope this will let me play the game of extending my car’s battery life as long as possible.
I don’t normally drive much or need the range except for road trips…. I have an LFP battery Model 3 RWD…. I still set to max 50% during the week as it may sit there for days and doesn’t need more. Once a week it’s set to go to 100% to get BMS updated. Before a road trip I have it go to 100% during the night so it’s ready in the morning. Same at hotels if driving on road trips, go to 100.
Another useful trick. When you do need to charge to 100%, you can use the car's "delayed charging" feature so the battery doesn't actually hit 100% until right before it's time to leave. This minimizes the amount of time that the car needs to sit around, idle, with a full charge.
Just be sure to shut off delayed charging when you do leave so that it doesn't interfere with public charging during the trip.
The video states that charging to 100% regularly will degrade the battery quickly. Please be clear what is meant by degrading quickly. If I keep my car charged between 30% and 70% does that mean my batteries will last something like 8 years but charging to 100% constantly it will only last 5 years? A difference of weeks or months in battery life time could be considered insignificant but degrading years faster would be a big difference. I think that’s the data people want and need, not just general statements like degrade quickly. If real world data exists giving people actual numbers drives the point home a lot harder than general statements.
Your guessed numbers are not too far off. Half the aging is what is being seen in the wild when owners charge to just 50%, etc. Comparing to 100% isn't great tho because there are other issues that might come into play besides just pack degradation if you stay at 100% regularly.
Basically set the lowest possible limit that is comfortable for your daily driving. Raise the limit immediately before longer trips.
After watching a recent presentation that Kyle shared I am going to focus on setting the limit to 70% and try to keep it in the 70-45% SOC. Then if in storage keep it at 30%. The presentation was really good and showed the data from torture testing and results. I used to use the 80-20 rule. 80% SOC limit and keep it above 20% on the bottom, but the presentation makes the argument that less discharge shorter cycles is better. Of course that is for regular Lithium ion batteries.
I’d like to watch that presentation. Where can I find it?
@@Dactylonian Here is the summary from The Limiting Factor and the link to the now private video.
How to look after your Long Range Tesla Battery!
Advice from Jeff Dahn, who's lab is partnered with
@Tesla
: ruclips.net/video/mN91pS1hSSQ/видео.html
The key takeways of this video are:
1) Jeff's advice in the video only applies to high nickel batteries in long range vehicles! Not LFP standard range vehicles.
2) High temperatures kill batteries. If you go on a holiday/vacation during the summer, leave your vehicle at a low SOC (state of charge). For example: At or below 30% SOC
3) Cycle within a narrow SOC range. For example: 40-60% rather than 10-80%. The cathode expands and contracts in a wider SOC range, which causes it to break apart.
4) On that note: The lower the narrower the SOC range, the better. That means charging frequently.
5) Avoid charging the vehicle above 75% SOC. Above 75% side reactions start occuring that cause degradation. This also reduces the volume expansion issues mentioned in 3).
6) Taking all variables into account, operating between 45-70% SOC and storage at ~30% is ideal.
7) Occasional high SOC and wide SOC range are okay! For example, the occasional roadtrip.
8) With good thermal management hardware and battery managment software, supercharging should have minimal negative effect on cycle life.
Watch the video if you'd like more specifics! ruclips.net/video/mN91pS1hSSQ/видео.html
It's worth watching because Jeff Dahn is one of the fathers of the Lithium Ion battery and his lab is partnered with Tesla.
Charging to 50-60% has less than half the degradation than at 80%. Its no wonder Kyle chooses that path. At 50%, a Model 3 has 125 miles of range which is more than enough to meet daily needs (typically). If you can charge at home every night, its probably the best charging habit. If you are using public chargers, then I can see charging to 80% so you aren't constantly looking for chargers. In the end, do whats convenient for you to enjoy the car.
I would say “Read the owner’s manual” - my car, not an LFP Tesla but a Mini Cooper S E, advises to let the car charge to 100% every time as it has a sophisticated BMS to look after the battery health. It only charges its 28.9 kWh battery at up to 50kW though. In the Mini there is no way to set an upper charge limit.
i have an LFP should I charge to 100% once a week and 80% the other times?
That’s fine, but make sure 100% once a week minimum when you’re using it to ensure it’s guessing the battery % correctly. Overall we don’t know enough about LFP degradation with Tesla’s latest BMS so it’s best to follow their advice - you won’t hurt it charging to 80% the rest of the time.
I charge my 36 kWh e-Golf to 80% or 90%, typically. Car has 56k miles, I estimate ~9% degradation.
We also have a polestar. We have it at 90% based on polestar recommendation. Should we lower it down to 80% instead?
that was the whole point of the video.....
You should if you want to maximize battery life, but my personal view is 90% will make for a marginal difference - so if the range on tap is valuable to you don’t stress too much about having it at 90%! I leave mine at 80% when possible.
Alternatively, look at the battery warranty and purposely degrade the battery within the warranty period so you actually get a useful life out of your vehicle with 2 batteries.
I don't think this would work. The battery degradation threshold needed to trigger a warranty replacement is very high, and modern batteries last a long time. Even if charged to 100% all the time and used fast chargers for all of your daily driving, you still likely wouldn't be able to degrade it fast enough, at least with normal driving.
I suppose if you really wanted to, you could choose to spend your entire day every day fast-charging the car to 100%, driving it down to 0%, and repeating, and maybe then you could trigger it. But even that wouldn't work because the battery warranty has a mileage limit, as well as a time limit. And even if it did work, you'd be wasting so much time degrading the battery, it wouldn't be worth it anymore - you'd do better financially by spending those hours working a job, instead.
When you say 40-50% if you leave the car a while, would you please define "a while"? A week, two weeks, a month? Thank you.
Anything much longer than a week
However, certain manufacturers like the Hyundai/Kia/Genesis EGMP products have a built in "pad" with their battery packs that won't allow you to charge above the "usable" amount, nor discharge below a certain amount. As such, when using my home level 2 charge station, I routinely charge my EV6 to 100%, as it recommends to charge to 100% at least once a month in the car's manual. Charge discharge cycles also add to battery degradation, so the more often you have to charge using a narrower charge window (say 30% to 70%), the more degradation you'll get. When you purposely limit your charge to 80%, you have to charge more often per month. I honestly think that with the battery management systems in modern EVs (those that have come out over the past few years), that limiting the charge to 80% when level 2 charging isn't a factor anymore. To be clear, I'm not saying to routinely charge to 100% when using a DC Fast charger, but at home for most of us on a level 2, exceeding 80% isn't going to cause long term issues. For long term sitting (routinely over a week), I agree with the 40% - 60% charge recommendation.
You are misunderstanding charge cycles a bit. Each time you charge doesn't count as a full cycle. If you charge from 70 to 80 that only counts as a tenth of a cycle. So doing more shallower charges isn't an issue, it still adds up to the same amount of cycles in the end. Full charging once a month is good, but I wouldn't do more than that unless you need the range.
The Tesla isn’t the only car, 2023 Mach e Std range has a LFP battery too. I also think I heard VW is using a LFP?
It’s the only one on sale as of filming. Base Mach E next model year!