The challenge with this kind of video is always that people will translate this to: EVs aren't ready, EVs are too complicated, etc. The purpose of this channel is education at a deeper level than you'd get from an owner's manual. Cars, whether ICE or EV, are extraordinarily complicated. Most people don't think about their ICE car's best practices, and yet they can still last a very long time. The exact same is true for EVs. As mentioned, cycle life of LFP is very good, even under challenging conditions. You don't *have* to think about it. You can just drive it, and it will last a really, really long time. EVs have much less regular maintenance, you really don't have to think at all to drive these cars. But if you're a dork that's way too curious about cars (that's me), then this is the kinda content that satisfies my curiosity. There are ways to make something that's already going to last a long time, last even longer. There are practices that can dramatically decrease life as well (same with a gas engine, don't hold it at redline, change the oil regularly, etc). My '18 M3P is six years old at this point, still under warranty, and still has great capacity remaining. I also have a new 6-speed coming to the garage soon - stoked to have a manual back in my life! 😎 **Edit 1: Does it even matter?** Many are asking what actual difference does it make between the different strategies, which I should have included. In the study, the worst strategy (75-100%) with the worst variables was at 90% of the original capacity in under 1500 hours of the 2500 hour study. At 1500 hours with the best strategy (about ~800 charge cycles) the capacity was still at 98% (really impressive!). Both of these numbers are fine; 800 charge cycles of a 250mi EV is 200k miles. As you can see, it's still a meaningful difference between the different options. With that said, these are at elevated temperatures, which accelerates degradation, so real world you could expect better results in both cases.
I see this as a 'best way to warm up your engine before driving' kind of video. You think it's super important when you get your first gas car, but then you realize nobody does it right and they all seem fine.
Agreed mate, I am amazed when someone asks me about my 2024 Model 3 RWD and I give out enthusiastically all the details, just to be met with "That's too complicated for me, I'll stick to my normal car". Have you ever talked to a car guy about his BMW M3??? If so, I am amazed that you're not driving a bike, though even them are downright complex if you ask the right person. I would suggest walking, but I had a neurologist once explain that to me and no way that I could do it😋
Texas summer, those temps aren't too far off. I was charging my EV the other afternoon and the heat caused a breaker to trip. Waited until the sun went down and everything was fine. I have LFP, thanks for the video.
Agreed. This is similar to people that obsess over engine oil. Can you change your oil every 3000 miles with $60-100 worth of Amsoil or Pennsoil Ultra Platinum and extend the life of the engine? Yes. Can you change it every 8000 miles with Supertech synthetic and still get a long life? Also yes.
Jason, this is an incredible honour! Thank you for citing my publication. I'm a long time fan of your channel. I watched your videos throughout my engineering undergrad degree, helping me understand my courses better. I'm a nanotechnology engineer & chemist by training, but while working on a Formula Electric student design team, I watched your videos to learn mechanical and vehicle dynamics concepts. I can't believe I'm at the point now in grad school research where my work can inspire your new content and help EV owners! Thank you for everything you do - your videos inspire the next generation of researchers and engineers!
I keep forgetting that Jason’s been putting out videos for almost 15 years… this comment goes to show how much can happen in that length of time, amazing.
LFP Best Practice #1 > Charge to 100% at least once per month LFP Best Practice #2 > When storing your car for extended periods of time, store it at a lower state of charge LFP Best Practice #3 > Operate at lower SOC ranges when possible LFP Best Practice #4 > Only plug in your car when you need to
You nailed it. Great summarization in 4 easy to understand bullet points! I plug in when I get to a quarter tank and fill 'er up, just like the old days. What could be easier to understand? Thx!
Can you explain number 3 in simple baby English? I get we shouldn’t charge to 100% all the time, once per month. Do I bring it down to like 15-20 then charge it up to like 75?.. better than 80? Or better that multiple 50/60 - 80’s
@@Justin-cx7hz Basically, don't charge more than you are likely to need. However, charging to 80% is perfectly acceptable as most degradation happens to the top 20%. Also, avoid unnecessary overnight topping-up when you have enough capacity for the following day.
About to hit 100k miles on my 2022 Model 3 RWD (LFP), and it only has about 4.5% degradation after being DC charged about 75% of the time (over 21 MWh). I full-charge it as much as I want, deep cycle it, and the car just holds up. I’m currently on a 10k mile cross-country trip with the car; really impressed with the longevity of LFP.
@@mesiroy1234Hydrogen requires insane infrastructure to be built - a mirror of the oil infrastructure we have but instead of most of the product being moved in liquid form, it’s a high pressure gas. We would need pipelines and ships and distribution hubs and manufacturers etc. That could still be profitable - after all, we _did_ build that infrastructure for oil and the profits are like nothing the world has ever seen. However, when we invested all that money into building oil infrastructure, 1) there was no competing technologies, so those profits were guaranteed and 2) Nations had empires they could cash in to pay for it. Today you would be relying on private investment. So it’s not that it could never be profitable, it’s that even a company with the war chest of Apple could set up an operation and go bankrupt in a year if a third of people stick with hydrocarbons and another third stay or go electric.
I don't think the cars allow the batteries to actually get down to 0%. They always keep some buffer to prevent damage even when the car will no longer drive. I would assume the only way to damage the battery is to leave it for a while after driving to 0% so the battery actually gets fully dead.
@@RyanSmithPhoto I seem to recall Tesla pushing an OTA in response to some natural disaster way back that gave people additional emergency range because of the circumstances. Predictably, this upset some people who felt that Tesla were holding out on them by having the battery health safety buffer at all.
From the paper: "It is important to note that we cannot make conclusive lifetime extrapolation statements, because these cells were stopped for destructive analysis after only 2500 h of testing. The best performing cells retained 97% capacity at that time, while the worst performing cells retained 76% capacity. Some preliminary unpublished results on smaller sample sizes suggest that LFP cells cycled at high average SOC may not experience a continuously rapid capacity fade and could recover in later cycles."
@@willbee51 Ah but my gas tank won't just spontaneously become an inferno in my driveway, on the road, or in a parking garage... But if you need to tell yourself that in order to believe EVs are somehow "better"... whatever works I guess. Gives you something to think about while you're waiting forever for a charge as well... I don't have time for all that, the 2 minutes it takes to completely fill my tank to 100% capacity where it will remain until I actually use it... think I'll stick with things that work.
@MadScientist267 Commenter didn't say better. Just stated a fact about engine degradation that occurs over time. Storing energy in any form has the potential for issues (a propane tank, gas canister, a lithium battery for a power tool, RC car, or battery bank, etc). Gas car fires do occur while in operation and after shutoff. Hybrid vehicles are integrating both engine and battery tech making for additional risk. If people could turn their home into a gas or diesel station, I suspect they would. EVs allow you to turn your home into a convenient fill-up station. While you can fill up more rapidly compared to an EV, your time is wasted elsewhere. Engine oil changes, transmission service, differential service(s), brake fluid change, transfer case service, coolant flush, power steering fluid, and "tune ups" are basic maintenance time (and money) consumers. Brake fluid changes and brake pads and rotors replacement are other service items rarely needed on EVs.
@@RT-rv5be Hence the quotes around "better". Better is what works and is a practical solution. Even if all of the "in car" issues with batteries and all of that are resolved, still have the supply chain issues. There just isn't enough lithium to do everything everyone wants to do with it. And before you backpedal to "what about sodium"... ok but then you're back in lower capacity battery territory again, granted not as low as some in history (cough, lead acid)... but still less. Something EVs really can't afford to be dealing with... ask any of the.. what are they on now.. 6th major iteration attempt? I've lost count. There's a reason they keep getting pushed to the side of the road in favor of the ICE. Don't get me totally wrong... I'm not completely "naysay" when it comes to EV... and they are closer than they've ever been in history to taking off and over... but for all the gains one might get, the downfalls are still too significant to do [at scale, this round]. But the idea the engine and transmission of a traditional drivetrain tends to fail in rather predictable ways, and there's "all this" in consideration of a battery... Naaa. That said, save the safety chat about gas tanks going off... yeah fires do happen, but they are readily extinguished and tend to stay that way... a battery fire is like nothing else... I'm good, thanks.
Really nice informative video. A couple of additional comments from a former battery management system engineer, to the real nerds out there: First, charging to 100% affects more than just range estimation. It also effects accuracy of cell-to-cell balancing, and hence actual range! Small leakage currents in some cells inevitably cause charge differences to accrue between different parts of the battery over long periods. The circuitry needs to correct these imbalances by "bleeding" charge off of the higher charged cells or cell groups. It can only do this if it knows which cells are more charged! If the cells aren't properly balanced one cell/group will hit 0% before the others, leaving energy on the table, and as a consequence the vehicle will estimate (and deliver) lower total range. Even NMC chemistry balances better when fully charged occasionally. Although more steep than LFP, the NMC charge/voltage graph's slope just isn't steep enough for
Thanks @InductorMan for your detailed information. I have a 2019 Model 3 LR RWD with the 2170 NCA chemistry. I only have 34K miles on the odometer. I've been tracking my car with ScanMyTesla since the car was at 6k miles. At that time the car still showed 325 miles @ 77.6 kWh nominal full pack (77.8 when new). I do let the car sleep at various SOC levels to help the BMS make a guess. I've only charged to 90% a handful of times and let the car sleep, and then drive it down to various levels to sleep all the way down to ~15% SOC. I will often come home from a trip at 15-20% SOC and let the car sleep over night, so my car does see a lot of data from the low end of the pack. I've generally keep the SOC levels between 70-30% SOC. Even on long road trips I can still stay within that range >90% of the time. Last fall I charged the car to 100% for the first time to see if I could improve the cell imbalance and give the car a better shot at balancing the BMS. I drove the car in stages (with 4-6 hrs of sleep) down to 8%. I only stayed at 100% for an hour, however. Not much changed from that effort in my readings the last year and only 5k additional miles except my NFP dropped from just under 73 kWh to just over 71 kWh. I think my BMS still lacking good high end info for good estimates. Since I've never need to push my SOC arrival levels to near 0 I'm trying to understand the best approach to balancing my BMS. I'm not doing any damage to my pack by not charging to 100%, my BMS is just not as accurate as it could be. Correct me if I'm wrong. On the other hand, if I did charge to 100% a few times a year and run the SOC level down with sleep periods down to single digits, am I really doing anything harmful enough to really matter? On Teslas I've wondered if there is a sweet spot for high levels of SOC below 100% that is "good enough" (say 82% just to make up a number) that isn't as stressful on the batteries? I also store the car between 30-40% SOC between drives. It's not a daily driver. As a road tripper 38% of my charges have been L3. TIA for any additional thoughts or strategies. I'm playing the long game to keep my pack as healthy as possible. I'm still showing over 300 miles of range depending on how the BMS is feeling that day. :)
I have a Tesla with an LFP battery. Until now, I could not find a decent explanation on the best way to maintain the longevity of my battery. Thanks for a great video.
Really need to cover actual degradation curves of LFP versus NMC and NCA. Because LFP degradation rate is much lower than the cobalt based lithium ion variants. The thermal stability and overall strength of an iron phosphate lattice is on a totally different level. This difference is extreme and needs to be covered in this video. Charge to 100% daily and forget about it. People stressed about solar lfp battery cycling years ago and we realized that calendar aging will kill your battery before cycling or cycling thresholds ever will. These batteries will last MUCH longer than the car will. There is zero logic in being nice to these batteries. They are designed to be abused.
Also the studies conclusions need to be accompanied by degradation curves. Over simplifying things without showing the actual data and degradation rates does not paint a clear picture. These batteries are so good at this point that The consumer doesn't need to worry about how they cycle the battery. Just charge it as much as they possibly can and forget about it. There are Teslas that are supercharged every time to 100% and the degradation rate is minimal. These batteries are meant to be abused.
@@WillProwse Solid feedback! I did include in the video that you really don't need to worry about it, and that it can hit 200k miles no problem. That said, it's not necessarily true that LFP outlasts NMC. Dahn showed in his lab that you can design NMC to outlast LFP. But from a materials standpoint, inevitably we need to move away from NMC. So LFP, and eventually sodium, need to be considered.
@@EngineeringExplained oh good points, so there are some NMC variants like Tesla powerwall 2 that can last an extremely long time. I think they added silica to the anode if I remember correctly. But overall LFP will degrade at a lower rate every time (and significantly more when internal cell temp is managed with a heat pump). NMC can last a very long time but cycling threshold should be managed. And the temperature has to be perfect. LFP is not as sensitive to temperature fluctuations. But they are harder to charge when they are cold. There are also slight variations in LFP variants that change degradation characteristics and electrolyte formulations that can change the temperature for which they are cycled at. Good example is Winston cells. The big difference with LFP though is the overall strength of the iron phosphate lattice. It can handle higher temperatures and voltages without the same issues.
@@EngineeringExplained managing pack temperature will slow down calendar aging. It is crucial for reducing degradation. Keeping a LFP nice and cool is the best thing you can do for the pack. Given it's better stability. something else to mention is the thermal mass of LFP is increased versus the cobalt based variants. Which means fast charging can be accomplished at a higher overall rate over the charge curve because the battery takes a longer time to heat up and is also easier to manage with heat pump than the cobalt based variants. This was also mentioned recently by rivian when discussing their new LFP packs. The Cobalt based variants can handle a higher charge C rate, but need to be cooled at a higher rate. So heat pump capacity is a huge factor when charging those. That's why older Tesla's without the heat pump would throttle the charge current pretty fast. The new model x and s can pull high numbers because of the new heat pump because it's massive. Which is required because they still use NCA cells. It's huge too, if you look at the front trunk of the model s, the new heat pump is massive haha
@@EngineeringExplained but the new Tesla powerwall 3 uses LFP because they are manufacturing them at larger volumes and overall calendar aging and thermal stability is better than the older NMC chemistry they used. It was good, and I love NMC, but it's not even close to LFP. Especially the latest cells available. Also the safety of LFP is fantastic compared to cobalt based variants. There is no self-propagating exothermic reaction when there is thermal run away.
The honesty and simplicity in your videos is remarkable. I wish more people "worked" this way instead of shooting "the all mighty truth" off of their mouths. "We're learning" "This is what we know, so far" "Things can change" 🙏💪
I’ve been charging my LFP Model 3 to 80% for daily use (down to ~50% each day with my commute), and 100% every Monday. About 30,000 miles in and battery degradation is about 3.5% or 10 miles. Based on Jason’s video and the study he references, I’ll likely change my practice and operate the battery in generally lower SOCs. BTW Tesla says LFP cars should be charged to 100% “AT LEAST once a week”, not “once a week”. Pretty substantial difference there. At least, that’s what my Model 3 says.
@@flowntn1989 I have a Model 3 with the LFP battery, I have done 50k miles in 3 years and degradation is just under 7%, I charge it once or twice a week to 100%, but It rarely every sits at that high state of charge. My climate is quite hot, south west of France.
@@flowntn1989Yeah, it’s very misleading. If the charge limit is always 100%, and you’re supposed to always keep the car plugged in, then it’s always going to charge to 100%. Doesn’t take a genius to figure that out. So I never set the charge limit to 100% unless I’m intentionally charging to 100% (once a week).
As an Uber driver I specifically chose the LFP. I charge to 100% every day. But I discharge it every day. So I'm going 100 - 15 - 65 - 7 back to 100. Repeat. If you're going to hammer the battery like that, get LFP!
i guess one difference is that your car starts with a 20 gallon tank, so leaving 10% as a reserve is always acceptable. fuel tanks dont shrink as the car gets older. batteries effectively do shrink as they age. making it more likely you'll eat into that safety buffer.
@@simonr23 Another difference is my car costs less than 10 cents a mile to operate and has an effective life span (at the rate I use it) of 500,000 miles. Compared to a car that costs over 17 cents a mile just for gas, then oil changes, breaks, transmission maintenance, belts, fans, radiator, muffler, spark plugs, cap & rotors, starter, alternator (I'm just thinking of all the things I've repaired recently on my gas car that don't exist on my Tesla.) Oh, and it's full every day I wake up, like having a gas pump at your home. So the one and only thing a gas car is superior at is long road trips. Which it saves you a few minutes at most. (Then you more than lose that time going to the gas station every week....) I thought the charging was going to be the think I disliked the most. Turns out it's the best part of an electric car. Unless you do that road trip, you don't even think about range. It doesn't enter your thinking. You just use your car without a thought to "do I have enough 'gas' / 'range'." You always have enough every day so you quickly get used to not thinking about it. It's awesome.
The other thing is, you need the bigger battery pack for Uber/Shuttle driving if you do hit 0% more than once a day. Mostly due to the thermal mass of the battery being fast charged, you leave the battery in a hot state for longer than average periods. There isn’t a quick fix other than swapping the pack out at a modular station. The fast charging isn’t bad, it’s not good if you’re only using fast charging and the climate isn’t letting the pack cool down to 18-25’c or 30-40’f room temperature. Keep it in mind, very few companies have aged a battery cell naturally for 20 years. It’s anecdotal evidence based on stress testing and artificial environments that accelerate the process. LFP has been around for this period of time, but batteries often have ‘dead time’ or settling time too. The things that we know about batteries are not concrete. Because it’s difficult to X-Ray or ultrasound the chemistry of the battery pack to see how it ages over time once it’s inside a car. So, fleet charging and fleet performance is often the more reliable source of widescale data. Averages, outliers and scale of use/range over the typical driver lifespan come from hundreds of thousands of cars being charged.
@@Toliman. Good comment. Good points. Typically I'll only fast charge once a day when doing a full long 12 hr day. From maybe 10/15% to 65-70%. After charging in summer I can hear the air conditioner working overtime to cool the battery pack. But you're right, until we have 20 years of EVs, we're making educated guesses on how real life driving will impact batteries long term.
It's funny, I've also been taught to never let you gas tank be too low. As it will hurt you fuel pump operating at that amount. How things change but stay the same. Lol.
Also, gas gauges can be surprisingly unreliable. I had a Mini Cooper S that ran dry while estimating 36 miles of range remaining, which would translate to well over a gallon (4L) in that car. I was extra-careful to fill up at 1/4 tank after that.
Some of the issue is sucking air, some of the issue is that if you only fill a bit at a time and run the tank regularly almost empty you can get water buildup.
What exactly is longevity (100k miles, 200k miles) and degradation (5%, 10%)? Depending on those figures, it may not matter at all. If longevity is measured past 200k miles and degradation is 5%, personally, I wouldn't care about that at all. As always, thanks for all the hard work you do putting these videos together for us!
I don't think the gradual degradation of the pack overall is that big of a deal in most situations. The real issue is that the battery is made up of thousands of individual cells that can never be perfectly matched. Even worse, the weakest cells in the battery take the worst beating and just one or a few bad cells can make the entire battery useless.
This was excellent information. I have learned to calibrate the way I talk about EV's, depending on audience. There is a lot of misinformation out there. For someone like my dad, who wants an EV but harbors a lot of irrational doubts, I just say "battery degradation is effectively a solved problem, the pack will outlast both the car and you OR it will fail quickly under warranty-but that's rare. Don't worry about it". Or for charging: "you will be able to charge off the 120V in your garage, and with the amount you drive it'll never be an issue". I don't get into the nuances of battery chemistry or strategy. I don't explain why it's worth it to install Level 2 charging for long-term savings. Not unless someone is already on-board (owns one or will soon). You have to keep it as simple as possible and stick to the benefits: it's a joy to drive; there's almost no maintenance; you plug it in when you get home and start every day with a 'full tank'. Nobody needs to be an enthusiast, or even all that savvy, to enjoy those benefits. EV's are uniquely well-suited to people who don't care about tech and see a car as an appliance (which is fine). My coworker yesterday said he'd love an EV, but doesn't fancy waiting 2 hours for it to charge on road trips. I opened up ABRP, plotted a 1000-mile trip and showed him exactly how much charging would be involved (you're basically stopping for 10-20 minutes, every 2-3 hours. You can cut that way down if you plan meal/sleep/fun breaks at places where you can charge, such that you aren't really waiting). Blew his mind!
Dave from the Off-Grid Garage has done a lot of trialing on LFP's . My understanding is that individual LFP cells get voltage drift over time and can develop a large delta between the highest and lowest cell voltage. When the pack gets charged to 100% it flattens out the differences.
So did I and I wish I would have done it a long time ago. I went with a 48v 110ah battery pack and a 600a controller AC conversion. Does this study relate to us and our lithium golf carts?
@chrisginoc it sure feels like it relates haha. I actually used a lifepo4 51.2V 100ah server rack battery and changed the stock bms on it. Shouldn't have any issues for the next 20 years lol.
Great video and great info. The only thing that I think should have been mentioned is how many charge cycles you are looking at. Just saying the life of the battery will be better or worse without context can scare people that don't know any better. LFP typically has a much greater cycle life than NMC, normally around 2500-3500 cycles. If you have a car that has a 200 mile range and you get 3500 cycles from your batteries, that's 700,000 miles of life (rough math). If you degrade the cells down to 2500 cycles, you're still looking at 500,000 miles of life.
Exactly! Also, how much battery degredation did they see with the 75-100% SOC pattern?!? Did they only see a loss of 5% total cycles over the lifetime of the battery? I'm good with losing 175 cycles to keep my battery at 100% LOL
Problem will not be cells but cell connection ,they could fali over time and electronic off BMS ,i have Dell Latitude with BYD LFP battery and after 4 years off using i still not see any difference in battery life
I have a M3 SR from december 2022. 190k km so far, 439 km of range when bought, 418 km right now (4,8% degradation). I charge it at 100% almost every single day, usually, from 10-15%. I live in Madrid, really hot in summer and mild in winter. I don't think that much about "best practices" when charging my car, I just enjoy it. I appreciate this kind of videos, so thank you @EngineeringExplained for doing them. EVs are awesome if you know what you are buying and have the ability to adapt to it.
I have a Tesla model 3 RWD with LFP battery. From reading a bunch of stuff, I figured that the reason they tell you to charge to 100% is because of the curve and not getting accurate readings from the battery management system which is just about what you were saying here. So I have always on a normal basis daily have my charger in my house set to, 50% I never need more than that much range anyway in a normal day, so that works for me. It keeps it low and charges to 50% every night once a week. I have the charger set to go to 100%. That is to reset the BMS as you said Ford says to do it once a month, but I’m more comfortable doing it once a week like Tesla says to do. If I’m on a road trip, or I know I need a lot of charge for a trip, I will charge to 100%. On road trips they charge to 100% at hotels. I’m not afraid to charge to 100% when it’s needed… But a normal day I keep it at 50%. Even when I’m doing my week, we 100% top off, it does take time for the battery to degrade down if I’m not driving for a day or two or a few. Thank you for confirms a lot of things that I do so I is good to see.
Best advice I've ever been given for Lithium based batteries is keep the charge above 20% and below 80%. Seems to have dramatically extended the life of my phone batteries.
Correct. The longer you keep it close to the nominal voltage (usually labelled 50%), the longer it will last. Manufacturers of most EVs intentionally reduce the range their cells are charged and discharged to, which is why my almost 10 year old Leaf still has ~70% of its original capacity, while my phone is only about 2.5 years old and is down to about the same amount.
I agree - especially when it comes to laptop batteries. I've worked in IT for over 30 years, and the most common faulty with laptops is battery degradation because they are constantly being kept at 100% charge. I now keep my phone battery between 20% and 80%, rarely fully charge it.
Incorrect, you can only do that if you know your car balances the battery while it is not full. Some cars (e.g. Some or all BMWs) balance at the end of the (full) charge. If you always stop at 80, if you have such a car, the cells will drift apart and be damaged after an amount of cycles
@@nickhexum01 Your battery will likely outlast the length of time your phone will get updates. That is how the elites deal with people like you (I would too if I could, but I couldn't make it thru the day) and force you to buy a new phone. :|
I really do enjoy these more technical videos where you get into the weeds of a study you are pulling from. A lot of people don't realize that the context of an experiment is just as important as the conclusions, especially when there are less studies overall because the technology is so new.
Great video Jason. I just watched your NMC video too and the charging strategy provided has worked for my Tesla with NMC battery with zero battery degradation observed in 9000 miles 👍
I bought a base Model Y just 2 months ago for the exact same reason: LFP battery. Love this car, best vehicle I've driven. We have solar panels and get free charging from the local shopping center too. And I can't wait for solid state batteries to become cheaper and get an electric motorcycle that can do 500km range and 0-100 km/hr in under 3 secs. What a time to be alive!
Completely trust and respect this guy. I’m new to ev and have just bought 2, one LFP and one NMC and had no idea of the differences. So much more to learn vs ICE! So essentially my make is shallow cycles for NMC and deep cycles for LFP with a periodic 100% Thanks taking the time to educate the masses, truly one of the best content providers 👍
Generally speaking LFP batteries are durable enough that as long as you don't charge it to 100% after every short trip to a corner store it'll well outlast the car it's in.
It's crucial to highlight the importance of accurate cell balancing, which only occurs at 100% charge in LFP batteries. Your battery pack is only as strong as its weakest cell, and regular balancing ensures that all cells age evenly, preserving the overall health of the pack. Worth noting the following; 1. **Cell Imbalance Over Time**: As LFP cells age, they can gradually go out of balance due to internal resistance variations, minor manufacturing differences, and environmental factors such as temperature variations across the pack. These differences can cause the cells to have slightly different states of charge (SOC) over time. 2. **Importance of Full Charge for Balancing**: The battery management system (BMS) of an LFP pack typically performs cell balancing near the top of the charge cycle, close to 100% SOC. If the battery is never fully charged, the BMS may not have the opportunity to balance the cells effectively, which can lead to increasing differences in SOC between cells. 3. **Impact on Cell Aging**: If cells remain imbalanced over time, they can age at different rates. Cells that consistently operate at a higher SOC may degrade more quickly, while those at a lower SOC may age more slowly. This can create a feedback loop where imbalance worsens over time, further accelerating the differential aging of cells within the pack. 4. **Compounding Effects**: The combined effect of different aging rates and a lack of balancing can result in a quicker degradation of the overall pack performance compared to a regularly balanced pack. Over time, this can reduce the usable capacity and lifespan of the battery pack. To mitigate these issues, it’s advisable to periodically charge the LFP battery pack to 100% to allow the BMS to balance the cells and maintain the pack’s overall health. However, it’s important to balance this practice with the understanding that frequently charging to 100% can also contribute to cell wear. A good balance is not to recharge after every trip if you have enough charge for the next trip. Then fully charge to balance the pack when you need more range and repeat. This minimises your effort, ensures the cells are well balanced and the range estimates are accurate. A good LFP pack should last 100s of thousands of miles.
Charge it to 100% twice a month with normal use is more than enough for the LFP for the BMS to calibrate. 25-60, 25-70 is what I'd do the rest of the cycles. I don't drive many km/miles a week.
It’s inaccurate to state that balancing only occurs at top of charge. This is highly dependent on the BMS control logic design, but most LFP systems can perform some amount of balancing throughout the normal range of use. There are some sections of the discharge curve where balancing can be performed more accurately, but overall it can balance anytime.
@@barygol definitely a good strategy! Your battery life is likely to be much more influenced by calendar aging than how much you cycle the cells (in your case).
@@krabkakes9535 You're correct in pointing out that while advanced BMS systems are capable of mid-cycle balancing, there's a potential downside when dealing with LFP cells. The flat discharge curve of LFP cells means that small voltage differences can be difficult to detect accurately. If a BMS, attempts to balance cells mid-cycle, it might inadvertently cause greater imbalance. This is because the voltage readings at various points in the discharge cycle could be misleading due to the minimal voltage differences between cells. Consequently, the BMS might redistribute charge in a way that isn't optimal, leading to increased imbalance as the cycle progresses. This risk is particularly relevant in systems where the BMS is not perfectly tuned to the specific characteristics of LFP cells, or where the cells themselves have slight variations in their discharge behavior that can occur with ageing. Therefore, while mid-cycle balancing is technically possible, it must be implemented with caution to avoid the very real risk of exacerbating imbalances, especially in LFP chemistries. So in reality mid cycle balancing only occurs (in LFP packs) when you have a significant imbalance and hopefully you never let your pack get into that state. So in reality the best (true) balancing for LFP only occurs at the top of the pack. I updated the response to accurate cell balancing.
@@makingstuffdownunder8405I have seen quite some tests of active balancers starting at a lower SoC. It always ends up in a mess that takes a long time to correct with top balancing. Going to 100% once a week and leaving it plugged in while the sun is shining on your solar panels is a great way to keep it all balanced and to get a feeling how your usage and range is in a typical week. Sunday may be the best day of the week for this if you take grid load into consideration and assuming you don't need the car that day.
LFP Tesla Model 3 owner here -- I'm constantly going back and forth on leaving the charge level at 80%, or at 100%? The issue is that in the car and in the app, when leaving it under 100% you will constantly be alerted that this is an issue. Even mentioning the battery could be damaged if not set to 100%. This is while keeping it plugged in. Because of this, i have left the charge rate back at 100% after a short period of time testing. I can say after 2 years of ownership, i haven't noticed any degradation at all in my normal driving. It could be that yes, high states of charge increase battery degradation, but with LFP its so slow that it really does not matter and you are better off getting the higher range. As mentioned in this video, the recommendations from Tesla may actually be the best answer, but they are not putting overall battery degradation at the top of the list of priorities.
I just bought a RWD MY and yes, I'll be doing the same. Driving to around 20-30% and fully charge it to 100%. Just like filling up petrol for an ICE car.
Unless you are going to be driving this specific car past 200,000 miles it shouldn't even be on your radar. The difference is splitting hairs into a couple percentage points of battery degradation difference one way or the other.
I've read many a paper on battery tech. The _biggest_ variable is the electrolyte. That is a proprietary and fiercely held witch's brew. One study (don't recall which) showed an MASSIVE difference in cycle lifetime from _just_ the electrolyte - the researchers made all the cells, and let various factories put their electrolyte in them. The researcher's blend worked to ~2k cycles, while the various production factories ALL exceeded 8000 cycles. Of course, there's also the lie every car manufacturer tells... zero ain't zero, and one hundred ain't one hundred. There's what the car tells you, and then there's the real, actual battery charge (voltage.) And this is before they out right lie about the capacity of the pack - eg. they're all 100kWh packs, but they charge more for those delivering 100kWh (Tesla loved doing that crap.)
I have an LFP Model 3 and it’s been very hard to figure out a best practice plan, so THANK YOU FOR MAKING THIS!! But this did burst my bubble a little bit on the magical bulletproof nature of LFP batteries…
One thing that was left out that is very important is that if your car is at a higher SOC you cam hop in and drive on a long errand without worry, but at lower SOC it may not be as practical to take unplanned trips. For this reason I always try to keep my cars above 60% SOC.
I always keep my Tesla charged to 80%, when i get home it gets plugged in. If i know i need more range, i will make it charge to 100% starting the charger so that it finishes within 30 minutes of departure. I know this might not be as good for the battery as if i kept it at 60%, but the company i work for pays me a mileage fee, and in 4 years they will have paid me enough money to buy a new car, so at that time i will sell the Tesla and probably buy a new one and as i have the money to buy one "cash" i dont really care if the car is worth some thousands less, because the remaining SoT is 5% lower than if i had been more "careful", and even if it is down to 90%, someone will buy it and be happy, because it will have more than enough range for his/her use, and they get a great car for a good price.
@@franklofarojr.2969 Best car i ever owned, but there is still room for improvement, especially the driver assist systems seems jittery, overly cautious and alarm sound wise, hysterical.
So glad you put this video out! Manufacturer recommendations and best for the longevity of the vehicle/battery do not always line up. Prime example is extended oil change recommendations by manufacturers. EVs are still so new it's hard to know what's actually best and who's telling the truth. Thanks again for clearing up some misconceptions about LFP. No battery "likes" to be charged to 100% all the time. Just like no engine does "better" with 10k mile oil changes.
The manufacturers should create a “Battery Assistant” in the dash, providing regular advice on how to charge based on the battery chemistry and previous historic charge cycles? Not rely on general principles.
There's no reason to scare the average Joe so their 15 year old car, which statistically probably won't make it to that age, can save a few miles of capacity
It is simple. For all batteries (NMC or LFP): 1. Do not keep them at 0 % or 100 % for long time (hours at most). 2. Keep them in range between 20-80 %. 3. Small cycles are your friend. 4. Charge LFP once every 2-3k km to 100 % to calibrate the BMS (do that before you drive somewhere, do not let it sit at 100 %).
@@pepegano_3578 not quite, "do not sit at 100%" does not apply to LFP, and cycles have very little impact except for very high mileage/year. For LFP, avoid 0% and charge to 100% when convenient and you're fine
@@mrfurieux9587 It does apply to LFP. When you are at 0 or 100 % most of the lithium is packed on one of the electrodes. This causes the electrode to have higher volume and its structure starts cracking (degradation - capacity decreases). The longer you keep it that way, the more it cracks. This damage from cracking is same in LFP or NMC or any other similar chemistry. On the other hand, LFPs separator degrades less (compared to NMC) when fully charged, due to smaller voltage. According to study mentioned in the video, cycling from 0-25 % had lowest degradation and cycling from 75-100 % had highest degradation. This directly contradicts what you say.
Since 2014 I’ve been building (and racing) electric race cars, and from the beginning the team chose LFP battery chemistry *because it is much safer* that NMC, but LFP has the added benefit that our rather abusive discharge/charge regimen is less damaging to the cells.
If im not mistaken quality LFP cells have such a high cycle life that you don't really have to worry about now you charge and discharge (only for long term storage), the calendar life is going to go out first unless the vehicle is a city bus or a taxi that is being driven 24/7.
3500 cycles till 80% of their original capacity for LFP VS 600 cycles for NMC. If charging to 100% everyday only takes of 3% of those cycles, I'm good with that LOL
For the first owner and probably the second owner, this is correct. Most people are not driving their EV 200k. The third owners might, this is where you may see a small degradation in resale value based on overall pack capacity. For the average person this is way too off in the weeds. The battery in your car is not like the one in your cell phone, it's not that sensitive to how you charge or treat it.
Current production LFP will have a life about 1 million km. A pertrol (gas) car would need an expensive overhaul well before that. If anything, static degredation of the battery over 20 years will be the failure cause before cycle life.
Generally: don't let your lithium batteries get hot. Definitely try not to use them whilst they're hot. Charge them slow because that keeps them cool. Don't discharge them too fast or they'll get hot. Don't fully charge them. Don't fully discharge them. From what I saw a few years ago LFP was king for cycle life but lacked the power and energy density. And that was improved by cycling from 40% up to 60% ideally. 80% worst case. Only charge up to >95% when you are going to need that extra capacity. Keep the SoC middling, in general. You should be able to leave your car plugged in all the time and the BMS manage your SoC to maintain optimal long term health. But in reality most systems aren't smart enough for this.
What's really cool (hot?) are the lithium batteries used in Radio Control vehicles. For absolute max power top speed runs, the batteries are charged into a "hot" state so they will output max power. The downside is they lose capacity VERY quickly such that only a few MAX power discharges. Those used batteries will still work great in more "normal" use however their ultimate life is shorter. Electric power for performance has similar tradeoffs to gasoline (internal combustion) performance power, but the electric has much more terrible tradeoffs it seems. A brand new internal combustion engine costs quite a bit less than a battery pack with motors included. I get the novelty and fun of electric power, but use that as the rationale, not some made-up crap about saving the "environment".
The 'don't fully charge them' advice is really a manufacturer issue: A lot of batteries in consumer electronics use a BMS chip that will slightly overcharge the battery to squeeze more capacity from it while greatly shortening battery life. Consumer electronics just aren't expected to last very long anyway.
And that makes for yet another issue that the EV companies are not addressing and yet another issue that people pushing back against EVs have legitimate concerns.
Yeah, this exactly. I own an EV from a generation that used an LFP battery and was ridiculously overbuilt (the Chevy Spark EV, which was one of GM's first gen mass market EVs.) The amount of battery protection they built in is nuts. It never fully charges the whole pack to 100%, and does dynamic cell balancing. Ironically, leaving it plugged in all the time when available is the best condition, because it will run the cooling system to keep the battery at good temps even when its hot outside.
I’d been told by multiple sources that LFP batteries were basically “the higher the better” when it comes to charge stage. I’ve literally been looking at starting projects centered around LFP batteries and planing on keeping them fully charged as often as possible, but now I’m just at a loss. I was even looking into specifically getting an LFP EV, and now I feel like just sticking with hybrids until solid state batteries are mature in a decade (hopefully).
That headline😱. I am a taxi driver, and I charge every day from 40-100% or whatever 70-100% because I think I could need the range the next day. Also the truth, most of the cars loose 80% of their value when they reach 200.000 km, and I think I will get to that mark with my LFP battery. Anyway, my new charge limit now is 80%😅
Manufacturers can (and I think do) lie in their state of charge level so that when the dash reads 100% the battery is actually only charged to like 85% because they want to increase cycle life.
Also, something to think about is it is good to fully charge to 100% and leave it charging over night to top balance the cells so that all cells are at the same voltage. If cell voltage difference gets too high it will degrade individual cells faster lowering the overall capacity of the battery pack an and degrading the pack lifespan as a whole. I would hope that newer EVs use higher quality BMS's that can keep cells perfectly balanced but its still a good practice especially considering charging LFP packs to 100% doesn't do as much damage as NMC.
Never tell a young person that anything cannot be done. God may have been waiting centuries for someone ignorant enough of the impossible to do that very thing.
Edit: since people are replying without watching, 9:50 supports my statement. The point is that operating at the top 25% is the most harmful to the battery, yes, charging to 100% is best for the BMS, but not for the battery. Most people are not going to be able to or comfortable with parking their car at 20% overnight, so my point is that cycling from 50%-25% is likely to be less harmful than the alternative of 100-75%, based on the data that lowering the max charge reduced the wear. So this is my take away from this for home charging: So my take away is this: BOTH types prefer lower SOC, but we can’t calculate LFP as accurately without frequent 100% charges, so manufacturers have chosen the BMS accuracy over the lifespan of the battery. Personally, if I ever get a car with LFP, I’m still setting my charge limit to less than 70%, plugging in daily, and just adding in a 100% charge like once a month or whenever I feel the BMS is noticeably out of sync. Not using the charge limit function purely because the BMS needs more frequent calibration is asinine.
No it's okay or even good to charge higher on LFP batteries. You just don't charge as often. You can go down to 20-30% and just charge up fully. This is unless you make regular long trips then maybe set it to 80% and charge daily.
I think you may have misheard, he pretty much said with LFP to cycle it less, ie. draw it down deeply (though not to zero) and charge it up to full or near full. Given the voltage spike right at the end, and the fact that higher voltages are one thing that can hurt, 90% in general should be fine with 100% on a regular basis. But even in the worst case scenario the results were in alignment with only 10% degradation after 200k KMs, or like 130k miles. The car will still run fine for years after that, just have slightly less range.
@@morosis82no, that isn’t what he said. The spike voltage is how we know the battery had completed charging, though that may contribute to the damage. He very clearly showed that the studies stated the lower you charge, the more cycles you get. 7:34 and 16:12.
If you live in AZ where it is hot AF in your garage, leave your Tesla plugged in and use CABIN OVERHEAT PROTECTION. It also cools the battery. Same for those in the northern climes. Leave it plugged in for winter months so the battery is warm in the morning.
1:40 I just got a 2024 Tesla Model 3 (my first EV). It says right on the info screen that it has an LFP battery. No need to lookup any 8th nr of my VIN.
Yep, the initial test was just a few of them, and they added more SOC ranges later. Would be interesting to see something in the middle, but I think the general trend remains (low SOC = better).
@@EngineeringExplained It sounds fairly similar to following a tractor trailer for fuel efficiency: the closer you are, the better for efficiency, but the more dangerous it gets, so it's a balancing act of how close do you get before you risk smashing into the back of them?
So let's say an LFP battery has 3500 charge cycles on average till it hits 80% of it's original capacity...These cells can be cycled so many more times than NMC cells and still have life in them...how much do these bad charging habits effect the final charge cycles, 2, 3, or 5%? I wish that information would have been shared in this video. If you're only losing 350 charge cycles in the end (and still get 3150 charges till 80%) I think that's worth the convenience of having it charge to 90% most of the time, and then every once in awhile charge to 100%.
I think he wanted to stick to the title topic, but he does mention that LFP is likely to last the life of the car and that the worst-case degradation in the reference test was still very low, but I agree that a headline of this story should be that LFP has *substantially* lower degradation rates than NMC, regardless of charge regimen. Many of the LFP cells being made to today will outlive their relevance.
When I built my custom electric motor bike 11 years ago I used LFP batteries, they were good for the time but needed to be charged to 100% fairly regularly to balance the cells and also reset the range. From there when you rode the gauge would count the Amp Hours and I knew how much I could use. The flat voltage curve meant this was the only way to know how much range you had left. A few years later I installed Chevy Volt cells and boy or boy they have been amazing! Far lighter for the same capacity and the maximum Amps they can put out is easily 3 times that of the LFP. At the moment the cells are 11 years old and working well so very happy!
Thank you for systematically going through battery technology, terminology, best practices!!! There are so many misunderstandings in the automotive industry. Classics like 4WD vs AWD or CVT vs eCVT (and then serial vs parallel eCVT). Thanks for bringing some order to chaos 🥳
It's simple: don't discharge it completely. Don't fast charge it if you can avoid it. Don't leave it outdoors in cold weather. Don't use it in the cold if you can help it. Don't allow it to get baking hot either. Don't use it if damaged. Don't park it beneath the place you sleep. Don't part-charge it and don't leave it unused for weeks or months at a time (importers please note). Don't get it wet and don't feed it after midnight.
Yes, because ICE vehicles don't have any complexity to their "best practices", and why I never need to have "a guy" to chastise me for missing various fluid feeding cycles for them.
@@gdutfulkbhh7537 Considering the battery will most likely outlast the life of the EV, just plug it in and charge to whatever you want (or according to the manual). I have an LFP and charge to 100% at work and home, for example.
I practice your recommentations since about 8 years for 6 battery modules 8S with 100 Ah Winston LFP cells used in my RV. A few weeks ago I tested the modules with a iCharger battery tester and got capacities ranging from 96 to 102 Ah. Of course, new cells directly from Winston had a capacity of about 110 Ah to compensate for initial lithiation of the SEI layer. Charging was and is still done to 3.40 V, with absorption time of 1 h. This is good enough because of the active balancers. No requirement to charge to 3.6 V, also not necessary for the gauge, as it is reset to 100 % at 3.4 V and counts Ah with high precision. The solar chargers use 4-wire connection for accurate voltage measurement without voltage drop errors. After absorption time has expired the voltage is reduced to 3.35 V/cell trickle charge. During storage the cells are kept between 3.2 V and 3.3 V. By accident 2 of the battery modules where down to about 1 V/cell for weeks. After charging them slowly with C100 to 3.0 V and then with C10 to 3.6 V/cell, they had a capacity of 102 Ah and 98 Ah respectively. They are back in service without any problems. My takeaway is that when LFP is handled with care they can have a very low degradation. YMMV. Regarding discharge of EVs till 0 %, this is really no deal, because 0% on the gauge are no real 0 %. There is still some buffer left, even when driven till dead. But they should be recharged asap to avoid deep discharge. Large SOC deltas cause higher cycle degradation because of the larger expansion of the electrodes, but with automotive use the cycle life is no problem during regular car lifetime. In cooler climates with temperatures below 10° C, fast charging and recuperation may cause gradual lithium deposition, with loss of active lithium and potential build of dendrites, even when battery temperature is above 0° C. EV batteries will probably mostly die because of calendaric aging. This is accelerated by keepin NMC cells above 60 % SOC and LFP above 70 % for an extended time. Calendaric aging doubles above this limits at 25° C. The car may rest after use or charging with battery temperature well above 30° C for a long time. The car battery has a large thermal capacity.
As a former product engineer for a lithium battery manufacturer for forklifts that only used LFP batteries, I can confirm this information for best practices. Also, dont keep the car in extreme temperatures for long durations. Extreme climates also degrades the LFP chemistry and reduces capacity. I know the cells I used to manufacture with had operational ranges of 0C-45C for charging and -20C-55C for discharge. I had applications where temperature control was necessary for the operation of the lift, especially when these were stored in -40 degree climates over the weekend, and operated in such.
Generally speaking lower is better for li-ion batteries, but realistically that's a lot of added weight, cost, and useless capacity if you don't tap into it. Range is an important metric so it's good to find a balance for what distances you're driving.
I think my tongue in cheek comment was missed. I was poking fun that the now infamous DCS batteries will not replace or refund batteries under warranty unless it has less than 70% of its rated capacity. DCS appears to have changed their policy after Oct 2022 to this new capacity figure from 80%. Hence, maybe a guide from you on how to protect these delicate batteries. 😂
@@EngineeringExplainedDCS is sn Australian 12 volt replacement car battery company that has been in the RU-vid news a lot lately for suing RU-vidrs for their honest reviews showing load tests and internal construction that are far below what they should be for the price point of the battery and other competitors.
Maybe they should just label the battery type right on the inside of the charging port, sort of like how a gas car tells you what octane or whether it's E85.
I live in Brazil and here neither Tesla or any other US car maker are selling EVs yet, although Chinese brands are invading our market with cheap and actually very good models. I bought a BYD Dolphin, a small hatchback with LFP battery and 204 hp and for now I'm amazed. It would be great to see you reviewing those car, specially because BYD has a proprietary technology for batteries called blade battery, which they say is safer and has more longevity. They even sell batteries to Tesla's. They are actually becoming so big that their ev sales have overcome Teslas! Another thing that will be a concern with the rise of EVs will be the power efficiency of the electric motor itself. This same car I have for instance is capable of consuming only 13kw per a 100 kilometers. And since US govern is very skeptical about China at all, it would be great to show what north americans are loosing by blocking this imports.
I have the Dolphin as well. Many of my friends have been completely blown away by how good it is. One of my friends went from "you gotta be kidding me" when i told him what i was going to buy to giggling like a schoolgirl after a hard pull from an intersection.
"The F is silent" Sorry if this was already mentioned (too many comments to read), but the F stands for ferrum, the latin word for iron. I suspect you knew that.....but didn't want to stray from the topic at hand. Stellar video as always!
Technically, it's not because they arbitrarily chose the latin word for iron but because the chemical Symbol for iron is Fe. Lithium Iron Phosphate = LiFePO4 = LFP
LifeFePo4 is the best! Less dense sure, but 10x charge cycles, and no risk of fire, and no tomfoolery to try and extend life. I power my offgrid backyard Observatory with Solar and a 200AH LiFePo4 battery. Same for our RV's house batteries.
You forgot to mention that LFP degrades 4x-5x slower than NMC (~4000-~5000 cycles vs ~1000 cycles). Also LFP is MUCH safer than NMC because it does not catch fire! Overall LFP will last longer than NMC.
@@ataksnajpera Yes, 180 vs 250 is way worse. For the same capacity battery pack, lfp will weigh 40% more and take up 75% more volume. Not to mention power density which is also lower. There's a reason that LFP are typically only found in lower range models, and why every performance EV uses NMC
Ford: divide the 5th digit of the VIN by the manufacturing month of the vehicle and multiply by 2. If the result is a prime number you have an LFP battery Engineering Explained: Every car manufacturer should be making it THIS EASY to determine what battery you have.
If you have a Tesla and can charge at home, disregard "LFP Best Practice #4 - Only plug in your car when you need to." When the car is plugged in and reaches the chosen SOC, the car will stop charging but still draw power from the wall for basic functions, reducing battery usage and in turn increasing the battery longevity. I've personally tested this by noticing the SOC decrease even with some power drawn from the wall outlet over long periods of inactivity.
Yeah I think that statement is specifically regarding maxing your soc and minimising how many cycles you do. So discharge deeply, charge less regularly but just send it when you do. I think though that I would set it to like 95% and just charge it once a week, typically don't drive that much as everything is close and I commute by bike.
@@EngineeringExplained It's crucial to highlight the importance of cell balancing, which only occurs at 100% charge in LFP batteries. Your battery pack is only as strong as its weakest cell, and regular balancing ensures that all cells age evenly, preserving the overall health of the pack. Worth noting the following; 1. **Cell Imbalance Over Time**: As LFP cells age, they can gradually go out of balance due to internal resistance variations, minor manufacturing differences, and environmental factors such as temperature variations across the pack. These differences can cause the cells to have slightly different states of charge (SOC) over time. 2. **Importance of Full Charge for Balancing**: The battery management system (BMS) of an LFP pack typically performs cell balancing near the top of the charge cycle, close to 100% SOC. If the battery is never fully charged, the BMS may not have the opportunity to balance the cells effectively, which can lead to increasing differences in SOC between cells. 3. **Impact on Cell Aging**: If cells remain imbalanced over time, they can age at different rates. Cells that consistently operate at a higher SOC may degrade more quickly, while those at a lower SOC may age more slowly. This can create a feedback loop where imbalance worsens over time, further accelerating the differential aging of cells within the pack. 4. **Compounding Effects**: The combined effect of different aging rates and a lack of balancing can result in a quicker degradation of the overall pack performance compared to a regularly balanced pack. Over time, this can reduce the usable capacity and lifespan of the battery pack. To mitigate these issues, it’s advisable to periodically charge the LFP battery pack to 100% to allow the BMS to balance the cells and maintain the pack’s overall health. However, it’s important to balance this practice with the understanding that frequently charging to 100% can also contribute to cell wear. A good balance could be to not recharge after every trip if you have enough charge for the next trip. Then fully charge to balance the pack when you need more range and repeat. This minimises your effort, ensures the cells are well balanced and the range estimates are accurate. A good LFP pack should last 100s of thousands of miles anyway.
I got my Tesla from the Berlin factory last June, haven't drove it much. Maybe once in a while every three weeks or so. Picked it up when battery was at 45%. Charged to 100% first charge using a wall charger. Afterwards charged once every 3 weeks to 100% from 80 - 90 ish percent. Been very busy this summer. I hope the car started in the right battery path.
I keep my Tesla Model 3 between 25%-70% as much as possible. Even on long road trips, I try to stay in this range, maybe with a bigger range of 20-80% when needed. This is convenient, because that amounts to about 2 hours of driving, with 15-20 minute stops. 2 hour stints are great for leisurely trips, and I'll be damned if I can get my wife back in the car faster than 15 minutes! On road trips with friends, the stop time is even worse!
Same here. I have a Model X Plaid with a ~340 mile range, so my trips are closer to 3 hours, and I keep my battery between 15 and 70%, but it's the same principle in play. I always wonder if people who complain about "frequent charging" have ever taken a road trip. By the 3rd hour, I need to stand up and take a break anyways (I've interrupted the planned route and stopped early to charge a few times simply because I wanted to stretch my legs), and even when I'm alone, I'm spending maybe 10 minutes in the car waiting to finish charging. A car which has Steam and RU-vid in addition to all of the other entertainment stuff I use while driving. Not much risk of getting bored there!
Yeah, stopping every 2 hours for 30 minutes is insane. I routinely do 5-12 hour trips depending on if I'm going to the coast or Texas or whatnot. Maybe 2 or 3 gas trips for 10 minutes after 3 or 4 hours depending on traffic. Stopping every 2 hours if not sooner for 20 minutes sounds insane. But if it makes you guys happy there ya go
Yeah I couldn't imagine driving for much longer than two hours continuously. Concentration goes, body hurts, just need a drink and a rest. There's very little I can do for two hours solid without a rest - even playing Civilization you need a bit of a break! Of course you'll still get these people who say they drive 12 hours solid without a break but generally they're talking nonsense.
The real question is: Do consumers need to care? If, let's say best case real world scenario is 80% capacity left after 100k miles and worst case is 75% - I genuinely wouldn't bother with all the charging/not charging/pecentages. If it's 80% vs 40% - then yeah, it's really important
In a modern EV with a battery bigger than 50kWh, the battery will probably outlast the car for an average driver anyway. But if you drive way more than the average driver it could have a significant impact on the lifespan of the battery. So for someone who drives all day every day I'd say it's worth considering. 80% vs 75% is actually quite significant for Li-ion because there's not that many usable charge cycles left after it drops below 70% SoH. I don't know if that's true for LFP though. Worth looking up.
@@auspiciouslywild what I mean is - what is "significant impact" mean in here. (not trying to pick a fight here though ;) ) In a lot of discussions people use words like that but they don't mean anything real. Like if you look at stock graphs (let's imagine one here) - the fluctuations look insane, because graph lowest point is actually something like 1.5 USD (instead of 0) and the top is like 1.55USD - the fluctuations plotted would look massive, but then if you would draw the same graph from 0 to 1.55USD - the change wouldn't even be perceptible by looking at it. That's just my convoluted way of saying - please put numbers behind words like "a lot/significant/etc.." because otherwise it's the same as kid saying "my car is fast. How fast? Like 5 of speed fast" Again not trying to pick a fight, just pointing out flaws in general discourse
@@vandalpaulius You can look up other lab studies on cyclical degradation. It's a slight exponential curve, the difference in # of cycles at 75% vs 85% can be a few hundred. That could easily be a year or two of capacity that isn't lost. Harder to say real world though, there's some decent data out there, but it will be a handful of years before we get a wide range of data from 10+ year old cars. Basically starting with the 2017 Tesla model 3 as that's when significant adoption started happening.
You forgot to mention one very important thing about LFPs. Their very flat curve makes it difficult for the BMS to know whether some of them are drifting in their state of charge compared to others. So this is the other reason (and perhaps the most important) why it's necessary to fully charge them, in order to balance them correctly.
Yes, very true. One of my e-Bike "safety batteries" is LFP and it is always very confused about its state until you fully charge it. On the bright side, the BMS gets less hot then the one handling the NMC battery.
This BMS calibration problem applies to computers and phones as well. Apple tried to apply this to their phones and got into heaps of trouble because customers did not understand what it was all about.
as an engineer too i truly appreciate Jason you once again explained this so well. real advice here: make more money and buy a new car whenever it gets old.
Thank you! I’ve been trying to tell people exactly what you’re saying in this video for a couple years now, but they won’t believe it about their LFP battery
I have a mach-e and even though I was knowledgable of battery chemistry your in depth explaination helped me understand more of the reasoning for charge rules. Thank you!
Dude ive been seeing your videos here and there for a couple weeks now. Those videos ive been watching were from 11 yrs ago. I only realized because somebody posted a comment about how he didnt understand why you had so many dislikes, I agreed so I went to give you a like. Thats when I saw that the video i was watching was 11 yrs old, and that all the other videos were also 11 yrs old. I didnt even realize it when I subscribed to your page
This is excellent advice! Let’s say I own an LFP EV and I have to park it on the street because I live in the city. I work from home, and would therefore rarely use my EV during the week unless I go for a weekend trip out of the city. They recommend leaving it at a 50 percent state of charge for an extended period of time. Since the car would probably only lose 1 or 2 percent a day this would be absolutely doable. Top up a supercharge before exiting the city and you are good to go! Different mindset from keeping it topped up all the time.
Read his pinned post above; even EV owners need not worry about it. He just likes to delve into the science. Also there is a lot of ICE crap I don't have to worry about, like oil & filter changes, clutches, spark plugs & wires, transmission fluids, air filters, fuel filters, ... Get a grip, its just different stuff, but less overall.
There is a lot of complexity to ICE cars that we are either used to or get used to now. From different oils in different climates or new vehicles. Gear box wear and tear. And now all these low emission zones and anti smog zones that pop up in Europe. It's not getting any easier.
For many, this is probably true, unfortunately. But of course that car will be a hybrid, so half an EV with all the complexity of both. The reason I got rid of my PHEV...
The idea of "only charge when you need to" is exactly the thing i needed to hear in order to not want an LFP battery. I will not remember to plug my car in if im "only chqrging it when i need to". It needs to be routine, and muscle memory based and plus what if i happen to need to drive longer that day? Say on my way home from work, i gotta syop by the store. Im not going to do math to figure out how many miles i really need. That is too much trouble and if someone is coming from a gas car and had to do this, ev's would no longer be the more convenient daily option if you're actually trying to keep the battery healthy. Looks like im going with NMC batteries from now on.
Any used car is risky. But much like buying any car, if you see a general trend on battery longevity, then you could probably bank on that. But I understand the information isn't always available
