Best practice electric vehicle (EV) charging for low mileage drivers

If your daily driver is an EV and you only travel short distances then you may be overcharging your battery. By reducing your maximum state of charge you can add many years to the life to your ternary lithium ion battery.
Notes:
- This information applies to ternary lithium (MNC) chemistry only, not lithium iron phosphate
- Slow (home) charging should be used to top up your battery each day
- High speed chargers will shorten battery life and should only be used on long journeys
00:00 Intro
02:27 Dynamic Stress Test (DST) results chart
08:41 Conclusions
Sources:
batteryuniversity.com/
www.chalmers.se/en/
#electricvehicle #tesla #evchargingstations
Full length video: • Should I be charging m...

[@MarksElectricLife]

This video is made with a specific audience in mind, EV owners who drive less than 25 miles or 40kms each day and charge at home. Statistics suggest that is the majority of commuters in developed countries. If it's not you then feel free to skip to the next video. Please don’t punch your computer screen and post angry comments as I will just take them down. I’m sure you can find better use of your time. The testing data pertains to "ternary" chemistry (e.g. NMC, NCA) and not LFP. Also note that a "DST Cycle" referred to in the Battery University study means one discharge and recharge to the levels specified in the test (e.g 75% - 65% SOC). However the industry term "cycle", when used to predict battery life, means one transition from fully charged to fully discharged and back to fully charged. So there would be 10 X 75% - 65% events before one charge "cycle" is clocked against the battery's lifetime cycle count. Key takeaways: 1. Most EVs allow you to set the maximum state of charge (SOC). You don’t have to choose 90% 2. Testing conducted by independent labs shows that leaving lithium-ion batteries at a high SOC for prolonged periods can shorten their life 3. Li-ion batteries are least stressed when at 50% SOC, which is why most products are shipped at 50% SOC 4. If you only use 10% (or less) of your battery capacity each day then there is no need to top it up to 90% each night. Indeed this could be counter-productive since your battery will reach 90% after an hour or so and then stand fully charged for up to 12 hours in your garage. 5. If you only need 10% for your daily drive then I recommend you drop your maximum SOC to allow for this (maybe 60%). You can always increase it whenever you are planning to drive further in a day. 6. You don’t have to follow this advice. Your battery, your choice. But this is a no-regrets approach since worst case it will make no difference to your battery life and best case it will enhance it. Data is sourced from The Battery University and Chalmers University of Technology.

[@justinbrown9680]

Thanks Mark. I learned a lot that I never knew before as I tried to understand the material you presented. I apologize if I wasted your time with unnecessary comments, but I can assure you I learned alot and am glad I took the time to try to understand. Without your video, I never would have found Evelina Wikner and all the great work she has done on your theme: reducing maximum state of charge. Thank you.

[@DataGeek903]

if 55-65% gives you say 5,000 cycles is that 5,000 x 10% x 100kWh = 50,000 kWh life. if 30-80% gives you say 1,500 cycles that is 1,500 x 50% x 100kWh = 75,000 kWh life. Or is the cycle defined as a full capacity DoD equivalent?

[@23davil]

It stands to sense that if you try and pull too much energy out of a battery eg going up steep hills on low battery capacity ur going g to twist the cells. Resulting in that when you try to charge it its twisting the cells. You have to have respect for your battery as you would do a load carrying mule.

[@duigiud]

How many miles can you drive on 10%? How do you figure out battery percentage to miles?

[@authorified89]

​@@duigiuddepends on the car. Your EV can show an average usage for a certain mileage. If you know how big your battery is and your own usage per mile, then you can calculate how many miles you drive in 10%

[@jeremystone5596]

I found the Cast studies more useful Case 1: 75-65% SoC offers longest cycle life but delivers only 90,000 energy units (EU). Utilizes 10% of battery. Case 2: 75-25% SoC has 3,000 cycles (to 90% capacity) and delivers 150,000 EU. Utilizes 50% of battery. (EV battery, new.) Case 3: 85-25% SoC has 2,000 cycles. Delivers 120,000 EU. Uses 60% of battery. Case 4: 100-25% SoC; long runtime with 75% use of battery. Has short life. (Mobile phone, drone, etc.) so to get maximum total output (energy units) out of the battery by charging 75%-25% you'll get >50% more out of your battery than 75% to 65%.

[@user-nq5qo5es4y]

One of the problems I see with this study is that they are using rather small "1500mAh pouch packs are used in mobile phones." EV batteries are designed different both in chemistry and in the assembled array with modules in boty series and parallel. This setup, I believe could be statistilcy different. Secondly, unlike phone batteries, most newer EV's have battery management systems which never allow you to charge to 100% even if this is what your car is telling you. This is a buffer on both the bottom and top end. Additonally they "balance" the individual cell when slow charged to 100%. I do think you are on the right track, but I'm concerned that your assertions may be over stated. Ultimatly I would hope the Batteriy Universiy would do some experiments that are more reflective of EV batteries.

[@Breakdancingsquirrel]

yeah i think most cars will be scrapped 20 years in anyway and bms are very conservative now so im pretty sure you could just do the worst you can and still have decent battery during the usefull life of the car!

[@MarksElectricLife]

A few people have pointed out that you can charge less often (maybe weekly) and use more of the battery capacity (say 85% down to 25%). They suggest this would give you the same outcome as charging more often and using less stored energy. This is technically correct however the reason I made this video is because that is not what the manufacturers tell you to do. Tesla, for example, tell you in their literature that you should plug in every time you are not driving the car and let it fully charge. So if you only use 10% of the battery each day and then recharge each night your battery level would bounce between 75% and 85%. This is a long way from the ideal SOC of 50%. What's more your battery is going to spend many hours standing at the 85% level. This video is aimed at EV drivers who only use a small portion of their battery's capacity each day (

[@JY-lg6ee]

I think you quoted Tesla's instruction incorrectly. Read the Tesla instruction carefully. Tesla said plug in your EV as much as you can when you are not driving it.. ***Tesla Said Plug in, Tesla did not said CHARGING **** , I text and ask Tesla many times with different customer services Rep, and validate that is that it meant. The reasons is very simple, plug it in so Tesla will use outside source to keep the battery at healthy temperature as well as BMS will use outside electricity to run it. For example, when I go home, and my battery has 56% left but I only need 10% the next day, I will still plug it in and slide the charge level on 50% , so there will no charging but home electricity is available for the car , So you are very wrong and misleading lost of people here

[@MarksElectricLife]

@@JY-lg6ee I’m not “misleading” anyone, just sharing the science. The problem is, without understanding the science, many people will just leave their maximum charge level at 85%-90% and plug their car in every day. This results in the battery sitting at high SOC most of the time. If they do as you do and reduce their maximum level to 50% that would be fine. This science explains why that is good practice.

[@JY-lg6ee]

@@jacobheinz8236 Sorry to said, you are very confused , please do more reading, by the way is your Battery LFP or NCA ??

[@Steve_in_NJ]

I just took delivery of a KIA Niro EV. It's a 11kw charging port for a 64 kw battery pack (range of 253 miles). The dealer charged the vehicle to 100%. I do not drive long distances (I'm retired, so no daily commute). I average about 10 miles a day! My last vehicle, after almost 3 years, only had 9200 miles (also there was the Pandemic, where nobody drove for weeks). I am planning on charging about twice a month under normal circumstances. My home charger won't be installed for another few weeks (local permits needed), so I should be fine. Everyone else says to charge up to 80% but you're saying 60%. Either way, one charge should last 2 weeks unless I take a short road trip. Thanks for your informative video.

[@paulgojenola1278]

A couple of things that would help the analysis. First, even though the curves are super useful the typical end of useful life of Lithium Ion batteries is ~80% because there is a ‘knee’ in the curve and capacity falls off much faster after that. But that data takes much longer to collect. Second, to calculate the years of life of the battery you need to factor in # of charges per year. Assuming the orange and purple curves and that user uses 10% a day… the orange curve requires 365 charges/cycles per year (9000/365=24 years. The purple curve would have 1/3 the charges/cycles per year (~122). Therefore 4500/122= 36 years. So the 10% a day user would be best cycling from 75%-45% for maximum life of battery in years.

[@templetonjp]

This is the same thought I had and makes sense to me. Unless there is something I'm missing with how "Number of DST Cycles" is being defined during this test the 75-45% options seems optimal. I plan on charging less than every single day and shooting for the 45-75% charge about 2x a week.

[@davor92k]

One cycle means one full capacity past thru the battery.. so if the battery is for example 50kwh - one cycle counts only after 50kwh have past thru the battery. So 1 cycle is not same as 1 partial charge.. So if you have 50kwh battery and you charge it with 5kwh (+10%soc) every day- that 5kwh is only 0.1 cycle so thats where you got it wrong.. I read the whole study and they explain it like that in the article.. too bad that this guy on video didnt explained that

[@davidnicholson6901]

Once again, Mark (referring to my comment on your first 16minute contribution) your video is very helpful. in my case I ave a varying mix of local trips with the occasional longer ones being around 50 - 60 km return. Outside these longer ones I can follow your recommendation. I usual simply top up (at the times of max solar cell production). Certainly more complicated that the petrol filling stations!

[@trixiepickle8779]

Thanks for this Mark, I'm a new EV owner - although have had an e-bike for years. Very useful and understandable information.

[@davidthomas4489]

This makes EXCELLENT sense. I am retired and unless I am traveling a great distance, I have been charging to 80% but only go to the GYM on Tuesday, Thursday, and Saturday, (20 miles round trip) and don't go anywhere else on the other days. I use about 10%. So, If I charge to 70% or even 65% I am good to go! Thanks!!!

[@JJN603]

this is one of the greatest videos on this topic thanks

[@evfusion4094]

Excellent video - thanks. I am changing my charging habits as a consequence - I have nothing to lose.

[@davebarnes4957]

Excellent video. Educational and short. We charge 80-30%, twice a month. So, for us, 1000 cycles is 25+ years.

[@edwardnack]

The Same

[@dennisdunbar2340]

I agree with you, it's better to try and keep your battery near 50%. I'm sure everyone would agree if you are using 20% of your battery each day and add that 20% each day before the next day, it's better to do 40->60% than 80->100% or even 70->90%. The first year of charging my 2022 M3LR I always plugged in and set it to 90%. For the past year I've tried to keep it near 50%. What I saw in the first year was it started with an estimated range of 573km and after one year it was 537km. Now it is estimated at 555km. 18km loss after 35K km is really good. I'm starting a new job that will have about 20% commute so I'm going to be charging to 65%.

[@iggyfan66]

Great info Mark! The idea of having a battery that lasts 5 years vs 20 years just buy changing your habit of charging is amazing. Also Love the T shirt! One of the greatest albums of all time. Cheers

[@MarksElectricLife]

Thanks Dan !

[@rickcowan7527]

Very helpful! Thanks for documenting your conclusions so thoroughly.

[@MarksElectricLife]

You're welcome!

[@WokACT]

Great info mate, will be very useful in the near future (hopefully)!

[@MarksElectricLife]

Thanks Warwick! You just got a new sub 😀

[@jozef5373]

I follow your advice for few weeks/months from your first video (65-75%). Now my Citroen EC4 has SoH 100,56% after 9 months and 11000 km. Before this pattern I tried to charge max 80%, usually around 60% only. Similar mileage EC4s and age has 95-97% SoH with same obd device and app (based on our forum). Maybe Im just lucky or it really works.

[@howardsommerfield1189]

I looked at the data provided (Chart @ 3:00 min) and come to different conclusions. First longer life is not the number of charges from the battery, but (in the case of a car) the miles / kilometers driven. In my analysis of the provided data, I added an assumption of a car with 250 mile max range (400 km) and converted the % of charge to miles driven: 100-25 = 187K | 100-40 = 180K | 100-50 = 187K | 85-25 = 300K | 75-25 = 375K | 75-45 = 337 | 75-65 = 217K. Clearly charging to 100% and very frequent charging shortens the used capacity (the ultimate goal) of the battery, and fully using the middle 50% of the capacity of the battery yields the most useful life (375K miles) from the battery. It would also be interesting to see a test that also compared the difference between fast charging and trickle (overnight in a car) charging. It is already known that trickle charging is better for the battery, but by how much? Also, this demonstrates that a larger battery will not only provide more range in a vehicle, but last longer, as well as have a better useful range when the capacity drops below the 90% or even 80% capacity.

[@Tooradj]

The critical question is what the x axis (Cycle) mean in this chart. If 1 cycle for each of these lines mean going from stated Low SOC to high SOS and back once, the chart is useless. The mileage value of all of them is basically the same and no matter which practice you chose you get the same number of miles out of your battery. However if a Cycle means equivalent 0-100 percent, then the OP’s conclusions stand. That is if 65%-75% is done 5 times of 50%-100% to be at the same place on X axis.

[@renaulttraficconversion]

Thanks for this video. This is excellent information. I have followed a daily charge regime for my Lead Acid batteries for over 40 years. My present vehicle is 10 years old and still has the same battery.

[@renaulttraficconversion]

I charge at 2 Amps from about 18.00 hrs to 10.00 hrs. the next day. Once a week I charge to 100%. I have bought very few batteries in the last 62 years.

[@johnreese3762]

Great info, thanks!!

[@balrajvishnu]

Awesome info mark. Someone pointed this in your previous video which I am going to restate here. If I pick a point between 75-45% that gives me about 100 miles in range. I typically drive 15 to 20 miles per day. This turn out I need to charge once every 4 days which gives me 4500 cycles and 50 years of battery life.

[@Breakdancingsquirrel]

so its pretty much saving the battery for the next user at that point right? i mean who keeps their car more than 10 years (especially when bought new) nowadays?

[@balrajvishnu]

You get a better resale value if you end up selling the car after 10 years.

[@tolgasobac8850]

Many thanks. Very useful information...

[@MarksElectricLife]

You’re welcome!

[@RionPhotography]

Since I got my Tesla and my home charger I’ve been charging to 75% which puts me right around 50% when I get home at night. Charging starts a couple hours before I leave in the morning so it doesn’t even sit still 75% for more than 5 minutes. My battery health has been steadily improving (it was very good to begin with on a low mileage car) and my expected range has increased about 5 miles in less than the first month. Definitely the way to go to spend as much time around 50% as you can.

[@Tooradj]

I doubt your Li-Ion battery health could improve. If you see your range increase, it is probably because your driving habits is different than previous owner. However my charging and driving practice is similar to yours to maximize the time it sits around 50% SOC.

[@shaunwalsh6354]

Useful information Mark, one of my worries with possibly considering but a second hand EV in the future would be how the previous owner has looked after the battery as regards charging. I know here in the UK many EVs are purchased on a 2-3 year lease or PCP agreement and I know owners that charge to 100% every night and say it dose not matter to them, because in 2 or 3 years time they will just change it for a new EV anyway, so it won’t affect them.

[@MarksElectricLife]

Fare point Shaun. There are some devices that can check battery health and I expect they will become very popular in a few years time when many people will be wanting to purchase second hand EVs. One thing you can do when going to inspect one is ask the owner to make sure it is charged to 100% when you arrive. You can compare the range reported on the display with the range specified in the manufacturer's manual for that model. This will give you a rough idea of how degraded the battery is. I will likely be selling my car long before the battery becomes an issue but it will be nice to be able to show the prospective purchaser that it still has most of its original capacity. It should mean a better sale price also (in a just world).

[@lenimbery7038]

I don't know about every manufacturer, but I think Tesla recommends occasionally charging from 100-near zero which allows the system to recalibrate in order to report more accurate expected range. @@MarksElectricLife

[@amitdesikar]

Thanks the video was very helpful.

[@MarksElectricLife]

You're welcome!

[@journey-Mein]

Thank you once again. I find both videos relatively concise and to the point. Your premise isn't mere conjecture and is supported by actual data. Assuming a tesla Y LR has this type of battery architecture you have provided a great service to me and my vehicle in this sea of reported proper procedures. i Wish they carried that chart down to a 60% Max SOC. I don't know if I have the nerve to drop my SOC to 70 0r less but i did take a leap and drop it to 75 for its first night. Gives more room if i find a free charger too . I was pondering something. it probably pertains to any vehicle. When i read the data i apply it to the charge scale indicated in the cars charge window. However many manufacturers and articles indicate that that number doesn't necessarily equate to the actual batteries true SOC %. I cant recall real world examples but for illustration. Manufacturer F may be conservative and when the cars scale reads its at 100% , it may actually only be at 80 in their attempt to protect the battery or improve longevity. if this were the case there may be a fudge factor for us paranoid drives. The end benefit doesn't change though were we are on the scale may. Being from New England US I can't help but admire the dialect , i don't smile for anything lately and admit i smirked at "ducks and guts" . Belated as this may be I thank you sir.

[@petermcandrew7787]

The problem with that chart is that it's based on the number of cycles, not the usable energy. Let's use your example of the average driver using 10% of the battery life in a daily drive. The "best" approach if you just look at that table would be to start each day at 75% and recharge that 10% each night, because that gives roughly 2x - 2.5x the number of cycles that the next line (75-45) does. But the 75-45 line gives you three times as much useful power each cycle, so you could charge your car every third day and get a longer life of your battery by using less cycles in the same chronological time. Crunching the numbers just based on where the lines cross 90%, it seems the best way to use an EV is the 75-25 approach, which gives roughly 1,500 times the battery capacity of usable energy (if you're using 10% per day, then you'll be charging once every five days). Next best is 75-45 (1,350x), then 85-25 (1,200x), then 75-65 (1,000x). All the 100% charging approaches seem to be around 750 times the battery capacity of usable energy.

[@JJN603]

if you can do another video on this stuff more in depth with more studies with like disrcharging to 10% and stuff like that.would be amazing

[@johnbb99]

I respect the work you put into researching this issue and making a serious attempt to find answers. As someone else pointed out the batteries used appear to be a different form factor and possibly chemistry to those used in most evs. Also was 20 degrees Celsius the ambient temperature or were the batteries actively maintained at that temperature? Just about every current EV actively manages the temperature of the battery pack. Next difference is what if any BMS was overseeing the battery charging process and protection? Was any cell balancing required or done? This may not have been necessary with the batteries employed in the lab tests, but It is essential that this is done with the multiple cell batteries in evs to maintain the best capacity possible. I have it on good authority (from BMW) that (in the case of the i3 at least) cell balancing only occurs at 85 to 100% state of charge. For that reason I shall continue to leave my car on AC charge when the battery is full, so that the BMS may do cell balancing and then shut down the charging process automatically. Which it does. This topic is certainly shrouded in mystery and it's very difficult to find authoritative advice on how best to treat your battery. I am concerned that lab tests done on atypical batteries, may not provide us with the answers we need. But thank you for trying.

[@rose415]

Great info ty

[@pilgrimcare3619]

... yes BUT if you charge only 10-20% each time you may be doing that every day as opposed to every few days so the number (rate of cycling increases) if the graphs were redrawn adjusting for an increased rate of cycling over time then I suspect the lines would be much closer.

[@sudhi5534]

Absolutely! I may be charging many more times to get the same range, which makes this entire video meaningless without considering your point.

[@bcduckworth]

Agree. The conclusions don’t factor this in, and are therefore incorrect in terms of battery life.

[@peteglass3496]

Indeed, 2000 cycles of 10% discharge are equivalent to 1000 cycles of 20% and the graphs need to be reconstructed to compare like with like.

[@stephenrussell6074]

There is little information about going from say 100% to 65% it is possible the degradation only occurs with a greater depth of discharge. So we can know nothing of that for overnight charging as the 80% figure is quoted mainly for fast charging as the charge slows down a lot between 80-100. In any case all of these need to be recalculated on the basis of 100-0 cycles worth of energy The 85 to 25 gives 60% of capacity so its 2000 cycles would be 6x that of the 75 to 65 so its cross over for distance travelled would be the equivalent of 12000 cycles at the 75-65 level so in terms of usability the 85-25 with a charge once every 6 days would take you a lot further than 75-65 charged everyday, assuming that the journey is 10% of battery in total. In any case for a car with a real world range of say 200 miles 60% would give you 120 miles 2000 cycles would be 240000 miles. The 75-25 is 50% so 100 miles range 3000 cycles 300000 miles, 75-45 30% 60 miles 5000 cycles for 300000, 75-65 20 miles 9000 cycles for 180000. In all cases the car is still going with 90% battery excluding any buffer between Gross and Net battery available, in many cases 10%. All of these are doing many more miles than a typical vehicle in its lifetime. I can also be certain that an 8 year old ICE car will be around 10% or more less efficient at 8 years old.

[@yhk1977]

Nice Info. I wonder if 85-25% SOC is the same as using 80-20% soc?

[@johnafotheringham4266]

Thanks for this. I’m currently trying to run my car on solar captured via battery. For this to work I have to charge the car little and often, as the battery and solar can’t do much more than fill 10% of the car battery. I had worried that doing more frequent, smaller charges might be a bad idea - before getting the solar battery I’d have waited until I needed to add 30% - but this video suggests I’m actually doing the best for the battery. I used to max out at 80%, but recently decided to lower this figure. When charging from solar+battery I max out at 3kW as opposed to the 7kW when charging from the mains. It seems to me that solar+battery charging the car turns out to be win-win-win in terms of depth of charge, rate of charge and cost Thanks for the peace of mind

[@MarksElectricLife]

Thanks for the positive feedback John. I'm glad this information helped to put your mind at rest. I'm in a similar situation to yours however I'm guessing my solar PV system may be a bit bigger. It maxes out at 7kW, which means I can take my SOC from 40%-60% over a few hours on a sunny day. I only use about 7% per day so I can get by with plugging in every third day. I recently installed a smart wall charger (Zappi) and it controls the energy flow so that only solar igets used to charge my car. It's a great investment and I am planning to make a video about it soon...

[@marceloandriolo819]

Greath information, thanks for share

[@davidjohnson7633]

This is great information, thank you for posting. But your conclusion is very flawed. For example, if one uses 10% of the battery each day and charges daily as you suggest, the battery would be good for about 9000 charging cycles before hitting the 90% capacity point, which equates to nearly 25 years. If one drives the same daily distance but charged every 3 days (45-75%], the number of cycles drops to 4500. Because the number of charging cycles per year is 1/3 of the base case, the 4500 charges are good for 37 years. Charging from 25-75% drops the lifetime charges to 3000, but now the same driver using 10% of the capacity each day would only need to charge every 5 days. Therefore the battery would last 41 years. This is much longer than your conclusion and is considerably more convenient as well.

[@daisiesushitam984]

Great video! If charging time is not a concern, would charging with a level 1 charger prolong battery life vs using a level 2 charger? *Charging from 40% to 50% daily*

[@satyan2428]

@Mark - Thank you. Really appreciate the clarity and depth of understanding. One question that pops up for me is "What about this whole thing concerning "Cell Balancing"" which is what some EV manfacturers advise as the reason to charge to 100% - How important is that ? Do batteries degrade faster when they are out of balance during the 40% to 60% charge ?

[@MarksElectricLife]

Hi Satya, two points. Your cells are less likely to become unbalanced if they are well "cared for" by avoiding fast charging and by not leaving them to stand at a high or low SOC. Most people will occassionally go on a vacation or road trip and need to charge to a high level (>85%). This occassional overcharging should be sufficient to rebalance the cells.

[@satyan2428]

@@MarksElectricLife that's wonderful Mark! Thank you. Your video has been very helpful.

[@MarksElectricLife]

@@satyan2428 You're welcome !

[@flyingspirit3549]

Superb video; upvoted! This is just the sort of information needed by people considering their first BEV purchase. Has anything been done on the effects of a mixture of discharge ranges? For example, what about the BEV owner who routinely drives 40 miles or less every other day, but then once a month makes a 1,000 mile trip and, for those longer trips, would like to be able to use as much of the battery capacity as possible? Would the overwhelming number of minimal charging cycles reduce the battery's ability to deliver full range?

[@MarksElectricLife]

Thank you! I think your question relates to battery “memory”. There is no evidence that lithium batteries based on ternary chemistry (eg NMC or NCA) suffer from memory. There is some evidence that lithium iron phosphate batteries can develop memory issues, although far less severe than the old fashioned nickel cadmium batteries. The information in my video pertains only to lithium ternary batteries.

[@flyingspirit3549]

@@MarksElectricLife Thanks for your reply; I really appreciate your taking the time to respond. This is most helpful.

[@user-td2nt6rd3z]

Would be great to know what happens to the batteries when you park your car in an uncovered parking? I have a garage at home, and can install a grade 2 charger, but what happens when I park the car in full sun for half a day, every day (hot part of the day in Melbourne)? Also, I commute for 2.5 hours a day, over 150km trip. Would love my next car to be an EV, but how and where do I fit in this? Will I have to exchange the battery in 3 years? Is there a chart where you can put all these parameters in to get a good estimate? Cheers, Zac

[@ed-th6ev]

You need to take into account the fact that 1000 cycles from 100 to 25 means 75000kw, while from 75 to 65 mean 10000kw (hypothetical 100kw battery). I want to see the same graph normalized for total energy consumption

[@ed-th6ev]

75000 kw consumption using 100 to 25 range, means 1000 cycles, means 90% capacity remaining. 75000 kw consumption using 75 to 65 range, means 7500 cycles, means 92% capacity remaining. So 2% remaining capacity difference between the so called "best" charging method and the "worst". If you don't explain this to people I consider your video plain misinformation.

[@sveinmedhus4156]

Totally agree. It is NOT about how many cycles you get, it is about how many kWh you can get out of your battery until the battery is worn out.

[@williammacey9502]

Exactly, recalculate the figures and fix your video

[@badboyblue9675]

Great vid

[@MarksElectricLife]

Thanks!

[@radiotowers1159]

Nice video and very informative if you only take the battery life and of course the money it will save you over the life of the car IF you intend to keep it for a while. However , certainly here in the UK the electricity cost can vary as we now have time of day pricing , where at times the cost per unit of electricity can go down to 2 or 3 pence per unit and even at times negative pricing for a few hours where you get paid to use surplus energy. This is compared to a specific EV tariff at around 9 pence per KWh. At times with the negative pricing the sensible way forward is charge to 100% to take advantage of Free travel costs and money credited to your energy account. This …may….. offset the degradation of the battery life, and complicate calculations.

[@richardhobbs7107]

I would say, 'At times with the negative pricing the sensible way forward is charge to 75% max.' Why? 'cause your not gonna use all that extra 'free' energy in your short commute, but charging the battery to 100% is gonna harm it over time. SO , keep your bat in the +/- 50% range by charging only in the 'free' and low cost times when you can. IF you know your next day will require more, then you charge above your 'norm'. take care, rh

[@jimusa9330]

I drive the 2024 CyberTruck that has the 4680 battery pack. I believe these batteries have the new NMC 955 chemistry. When I took delivery, the Tesla rep said I should charge to 100% once a week. This doesn’t make sense and I won’t follow this advice until I get additional information back up Tesla’s recommendation.

[@willie346]

Great information. First time actual data has been presented. But why charge daily? If you charge weekly (enough for me), 1,000 recharges means my EV would last 20 years. The battery would remain effective far longer than the usable life of the vehicle.

[@MarksElectricLife]

Thanks for the positive feedback. You make a very good point. I only use 7% of my battery each day so I plug in every 3 days. I charge up to 60% and only plug in when it gets back down to 40%, three days later. If you can stretch yours out to 7 days that's even better. You should get 80 years from your battery 😊

[@hrpzwift945]

What is a DST cycle - For the Green line 85-25% the 90% capacity is reached at 2000 cycles and for the Magenta line 75-45% the 90% capacity is reached at 5000 cycles. The Magenta line seems to be a good choice from that perspective. But what is a DST cycle, If it means that one DST cycle is charging from 45-75% for the Magenta and if one DST cycle for the green line (25-85%), the you will need twice as many DST cycles for the 45-75% charge compared to the 25-85% charge - which then does decrease the difference of the number for cycles from 3000 to only 1000 cycle. Basically what is a DST cycle is it every charge regardless of how much you charge - is a 45-75% and a 25-85% charge, both considered at DST Cycle ??

[@aeroncaflyer8474]

But you don’t seem to take into account that if I charge my battery between 80%-25% I only need to charge once a week so it will only be 52 cycles per year?

[@drevent7677]

exactly right and at 52 cycles a year 1000 charges is 19 years+

[@Radioman.]

What battery manufacturers mean is a complete charge is going from 0% to 100% capacity. Therefore if your battery was run down to 40% and you added charge to bring it to 65% you could perform that operation 4 times. The manufacturer would consider that one complete charge. This is what I was lead to understand reading the literature concerning Li-Ion cells. To put it a different way, a battery might last 2000 full charges or 8000 quarter charges.

[@gabrielfmoraes]

Does this study fits for Nickel batteries as well? Or just for Lithium batteries?

[@topz1067]

Hi, thanks for sharing your knowledge. I also commute for about 30-40 kms a day, and after watching your video, I now try to keep my battery between 40%-60%. So I only charge about once a week. Do you know if I can use DC fast charging points for my weekly charging or is it better to AC charge, even though I only charge once a week? Thanks!

[@MarksElectricLife]

Slow charging is better for your battery than DC fast charging. A 20% recharge should be easy to achieve on an overnight AC charger, so I would set your maximum SOC to 60% and then just plug into your wall outlet whenever you notice the SOC has fallen below 40%. That is what I do.

[@ramonennik2536]

Does it matter how often you plug it in? Let say you want to charge only on solar, but a cloud passes by and continue after the sun shines again, would it affect the battery in a bad way?

[@farukamin3619]

Can you suggest what would best practice if I drive 150k each day? I appreciate your suggestion. Thanks.

[@runningdowna997turbo]

I am wondering if I use a DC fast charger at 50 to 75kwh instead of 120kwh and only charge to 70%, is that much worse than using my level 2 charger charging to 70%?

[@kelalamusic9258]

Very helpful information. I have a 2022 Nissan Leaf. I’ve had it for about 2 1/2 years and have only driven about 2500 miles. Obviously we don’t use it that much as it’s for around town use only. I plan on keeping it for as long as possible. So, hopefully following what you say should extend the years of use. Much thanks.

[@MarksElectricLife]

You’re welcome. Thanks for the positive comment.

[@stevezodiac491]

sadly, even if you don't use it much the battery will still degrade. lithium ion batteries degrade with use cycles but unlike ice cars degrade with time as well. The battery will degrade just sat there. My leaf started showing battery bar loss at 5 years old. it is now 8 years old and only 40k miles driven and has lost 4 bars and 33% capacity, even though it has been well looked after. My advice to you is to sell it before the battery bars start to disappear, because when they do, nobody will buy it like mine and you will be stuck with a short range local shopping trolley tied to your home charger range, with no option to do long journeys, as mine is, until it is scrapped, when it is not economically viable to change the battery on what is otherwise a good car.

[@scottwylde8528]

It's a very good comparison of Apples and Oranges! hehe 🤣

[@jaslarja]

This also applies to LFP batteries right?

[@RMElsa]

@marksjustimagine The test setup was designed for individual cells and their SOC and not for entire battery modules and the Hi/Lo SOC programmed by the BMS - correct? The BMS are configured in such a way that the cells are not really empty at 0% SOC and there is certainly 3-5% left until the BMS protects the cells from deep discharge and takes the battery offline. The optimum state of the battery is therefore not the 50% displayed in the vehicle, but rather somewhere around 45%. For short-distance drivers, a SOC between 30% - 60% would be a good range and optimally between 35% - 55%. What is your opinion on this?

[@MarksElectricLife]

We don't know the exact test conditions for Battery University testing but certainly the Chalmers testing was on whole EV modules. We also don't know the BMS hidden reserve for any specific vehicle. That said, 50% on the vehicle's charge indicator is likely to be somewhere close to actual 50% SOC. So if you only need 10% for you daily drive you are probably best to work within the range 40-60%, so your battery spends most of its standing time at the 50% SOC.

[@RMElsa]

@@MarksElectricLife I see the data as an indicator, I personally find your suggestion of 10% too extreme, as many other factors also significantly influence cell degradation. For example, if you drive progressively, accelerating hard, the battery is challenged even more when the battery is still cold, which probably shortens the life many more than +/-15% around the 50% SOC charge/discharge.

[@owenanderson9395]

How much of this applies to LiFePO4?

[@markkennard861]

100% no matter what. Easy. Just read the instructions.

[@slonWDFPF]

Seems like the best way to charge is 25-85% as said by the vendor. Because you will need to recharge the battery rarely, it means that you dramatically decrease the number of recharge cycles. For 65-75% you will actually need to charge each day...

[@MarksElectricLife]

That would be true but only if you ignore the manufacturer's instruction to plug in every night. Tesla advise to do that in all their literature. If you only use 10% each day and plug in every night you will be bouncing between 75% and 85%, which is not ideal for longevity.

[@obieWanmotivation]

Hence why I agree with your opening point (Tesla owners, don’t come for me) that your daily average mile should dictate the top SOC as opposed to the recommended “1 size fits all 80 to 20”. In a nutshell, if you’re driving 20 to 30 miles per day, you can potentially lengthen your battery life by reducing the top SOC after charging to no higher than 75% until you have a longer than normal mileage day. It makes sense.

[@wittayachannarong1945]

In my country many people practice ‘rebalancing battery’ which is every 3 months you have to use up battery to less than 10% and charge up to 100%. Is this correct? Please advise.

[@user-oc2eb2on7m]

Thank you for explaining this report... i was under the impression that i needed to charge daily... i do keep my battery at 70% but now will reduce to 60%... is that a bad to charge daily ? I was under the impression that the less depth of charge the better it is... and the sweet spot is to be around 60_65% since the car never has access to a full battery storage... thats why i was keeping mine at 70... now i will reduce to 60 ....

[@MarksElectricLife]

Hi, charging daily is fine. The main thing is to not leave the battery for long periods at high SOC. Optimal charge level for lithium batteries is 50%. The closer to 100% or 0% the more stress you put on the battery. So if you only need 10% of your battery each day then it's probably best to charge it to 55% each night and then run it down to 45%. Then top it back up to 55% each night. In my case I charge mine to 60% and then run it down to 40% over three days, at which point I top it back up to 60%.

[@user-oc2eb2on7m]

Why not charge daily so that u only have a 10% doc....? Why take it down to 40% soc when u have the ability to avoid this.... what i get from the report is that u need to keep the battery on that optimum voltage point of 3.92v which equates to 60_65% soc... and the less depth of discharge the better u will be in the long run.... please correct me if im wrong....

[@MarksElectricLife]

@@user-oc2eb2on7m Hi, the 3.92V is a ceiling, not a floor, for maximum longevity. So charging to 60-65% is my objective. The greater sin is charging to high levels and then letting the car stand with a full battery.

[@user-oc2eb2on7m]

I think we definitely agree that holding that high voltage over a longer period is not ideal... my car for instance has an 82kw battery but i can only use 76.6... that is more or less 10% safety buffer... provided that 5% is for top and bottom thats where i landed on 70% soc for my vehicle... the only difference on your recommendation is on the depth of discharge.... i like to keep that to a mininum as possible so i charge back daily regardless of 1-10% drop on the battery level... i still have tp dp some calculations to see where this 3.92V equates on my battery.. but to be honest i think im pretty close once i reach 65_70% on my vehicle.... thank you again for bringing to light this report... cheers...

[@jjamespacbell]

Please correct my assumptions from the above graph. Based on my Model Y long range 300 mile range Balck data: 300 miles * delta of 75% = 225 miles times 4,500 DST cycles = 1,012,500 miles travelled Yellow data: 300 miles * delta of 10% = 30 miles times 4,500 DST cycles = 135,000 miles travelled After 7 times the distanced travelled I would expect a lower retention.

[@MarksElectricLife]

Hi James, there is indeed a lower retention. On the black line your battery will only have 78% of it's new capacity, whereas on the yellow line you can still charge up to 94%.

[@sgsuper1150]

I think up to 90% is ok if you discharge the battery straight away but never charge over 90% unless the cell balance is at 100%. Then you have to charge to 100% every month. Only tesla have this low state balance so it's not really practical in most evs.

[@dadlaponizil3687]

Hi and thank you for an excellent guide on how to optimize the life of a Li ion battery. We're in the market for a used EV. But as I learn more about these best practices, it gives much pause. With a used EV, one knows nothing or very little about how it was charged. Do you know of a reliable battery health test that one can ask the dealer to provide? If so, what shall I ask for? Gratefully, Dadla.

[@MarksElectricLife]

Hi Dadla, thanks for the positive feedback. There are expensive machines that can analyse and report on battery health. If you are buying from a dealer you could request one of these reports before deciding to purchase. If buying privately this may not be an option. In that case the best thing you can do is ask the seller to have the vehicle charged to 100% at the time you have agreed to inspect. Log into the manafuacturer's website to find out the maximum range of the vehicle when new. Then compare that to the range indicated in the instrument cluster on the seller's vehicle. Dividing the smaller number buy the larger will tell you the percentage of battery degradation - approximately. Also confirm how much of the manufacturer's warranty is remaining on the battery.

[@dadlaponizil3687]

Dear Mark@@MarksElectricLife This is super helpful. One follow up question. We just purchased a Niro EV from Carvana. It came charged to about 65%. When we got home, we charged it to 85% using a fast (40kW) charger and then topped it off at home to 100%. Now the GOM is saying 208 miles. The EPA estimate for this vehicle is 239 miles. So my question: is this 13% lower range indicative of battery degradation or is this the software algorithm calculation and projection of mileage based on the previous driver's habits, temperature, use of HVAC, etc.? One EV tech told me that one can reset those historical parameters and return the GOM to the factory setting. I do not know if that is possible without a direct connection to the car's control system/software. Thank you again for helping us. By the way, we are returning this Kia Niro due to heavy window tinting and concern about the range.

[@MarksElectricLife]

@@dadlaponizil3687 Hi Dadla, I'm afraid I can't answer your question as I'm not familiar with the Niro software. For Teslas (the car I own) the GOM figure is based only on EPA efficiency multiplied by the kWh charge in the battery. Whilst this doesn't reflect the true range you can achieve on any given trip it does give you a pretty good approximation of the level of battery degradation. How old is the Niro ?

[@dadlaponizil3687]

It is a 2022. Gosh, now I want our next car to be like the Tesla's simple GOM. I like the Niro EV so will likely get a new one of those and then maintain a "healthy charging protocol" like you outlined. Does it seem to you like this "proper charging protocol" is the auto makers' best kept secret. I bet that most drivers charge to 100% on a fast charger and ruin the battery faster.@@MarksElectricLife

[@SmartMart1658]

New research has shown that supercharging your Tesla is not as harmful to the battery as was first thought. Also some new battery chemistries will last longer if you do charge them every time to 100%. Note that for lithium iron phosphate (LFP) batteries, it is OK to charge to 100% every day since the chemistry is more resistant to degradation.

[@caleb7475]

Think that purple line is the one to aim for.

[@Emcee_Squared]

Why is there an outlier in the orange line?

[@ronedwards8239]

What many don’t understand is if you charge for example to 60 or 80% that is not a full charge cycle. I sold my electric scooter to a guy who works for Lucid Motors. He drove a Tesla. He also told me to charge to 60%. My plan is to charge to 60% during the week and 80% on weekends as my trips are longer range.

[@MarksElectricLife]

Hi Ron, that may be an area of conjecture but the scientists who conducted this research define a cycle as one charge period where the SOC is increased from the target minimum to the target maximum for each data set. For example, in the case of the green line a "cycle" is one recharge, taking the SOC from 25% to 85%. For the orange line it is charging from 65% to 75% SOC.

[@mdmattingly1]

​@@MarksElectricLifeIt seems like the fact that the car would need to be charged 6 times as often should be considered. Someone who only uses 10% a day isn't going to be charging from 25% to 85% each day.

[@aneeshzutshi3419]

@@MarksElectricLife You have a completely incorrect understanding. A cycle is always counted as 100% equivalent. 70% to 50% is only counted as .2, so one cycle is 5 times movement of 70% to 50%. Cycle is defined the same across all experiments otherwise the experiment would make no sense.

[@MarksElectricLife]

@@aneeshzutshi3419 "always"?? Respectfully, you are making assertions about the testing conditions without having read the paper or asked it's authors for clarification of the test conditions. If you read the paper you will find that the authors differentiate between "Full Cycles", what you are referring to, and Dynamic Stress Testing (DST) cycles, which are short cycles between a nominal minimum SOC and maximum SOC (e.g. 50% to 70%). For the chart being discussed in this video they are recording DST cycles, not Full Cycles.

[@springhillfitness6837]

​@@MarksElectricLifehi, I enjoyed the video and think you give good advice. However the difference may not be as large as the chart suggests due to the way a charge cycle is defined. For example if we assume a range of 300km, the 85-25% test yields 2,000 cycles or 360,000km while the 75-45% test yields 5,000 cycles or 450,000km which is certainly better, but less dramatic than the chart suggests.

[@alanjoseph9814]

It’s too bad the chart isn’t in total kWh for each of the charge ranges. For instance, for 45% to 75%, you get 4800 cycles and for 25% to 75% you get about 3000 cycles. So only going down to 45% sounds significantly better, but in reality for the accumulated energy you get, it’s about the same. I’m getting picky. But the overall video is otherwise quite good.

[@foobar3895]

Anyone knows whether this also applies to LFP? Tesla wants me to charge it to 100% at least once a week and it just feels wrong.

[@frankvanderzwet4213]

I really appreciate referencing the chart on battery life vs charge cycles. However I think it would be better served if it was translated into total km travelled or total energy used. It's misleading to suggest that charging from 25% to 100% provides 1000 days of battery life before it degrades to 90% capacity. 1000 charge cycles does not equal 1000 days, especially if you only need to charge every 3rd day or so. If my car has a range of 400 km on full charge but I charge it from 25% to 100% I can travel 300km 1000 times or 300,000km before I'm at 90% capacity. If I charge from 25% to 85% that means I can travel about 240km 2000 times, or about 480,000 km before my capacity is 90%. Definitely better but not double as you've suggested by equating charge cycles to days.

[@chrisnewman7281]

I charge to 90% only because I realise that I’m using the car as a battery as a Energy store to trap surplus energy from our Solar rooftop system. On the other hand. We are not planning to hold into our current EV for any longer than two years at most. Bearing in mind that all batteries have got a reserve even if you charge to 100% there’s a further at least 10% so 90% probably closer to 80% of the actual capacity of the battery.

[@julianguffogg]

What about LFP?

[@derekness7900]

I have two EV s in the family and I charge to 100% mainly at 2.3Kw. I don’t buy this charge to 90% business. Back in the 70s I used to design batteries for emergency lighting which were on continual trickle charge , so I get this . The battery systems of today in cars have very good control systems so they will not allow an overcharge situation that could give the issues that have been mentioned. This is not a problem so all of you that charge to 100% can sleep safe in your beds your EV will be just fine - believe me I am an (ex) battery development scientist!

[@pauld3327]

Bad advice.

[@Dzaen2]

got any documents that supports anything you said?

[@JohanLofgren-jc4mh]

Maybe this advice is good for some batteries, but not every batteries on the market. Follow the manufactorers advice.

[@jensn6490]

Do we divide our commute in half and add half to 50% charge? My commute uses approximately 27% of the battery charge therefore should I charge to 63.5% or 65% for ease of use? I would start at 65% and end the day at 38%. Is 38% too low for optimal health? Thanks for the video

[@MarksElectricLife]

That would be the correct approach. 38% is not too low. Anything over 20% is fine.

[@rhiantaylor3446]

As you describe the main chart, you would need far fewer 100 to 25% cycles for the same number of miles driven, as compared to 75 to 65% cycles - only 1/7th as many - which would explain why you only get 1000 of these high mileage cycles, as compared to over 7000 shallow cycles. I think that in simplifying, you missed out some of the key detail in the way these tests were run.

[@scotttitensor8557]

Please do a report on LFP battery pack in Tesla model 3 RWD. Tesla says to charge to 100%

[@grahamf695]

If you discharge from 100-25%, then you are using 75% of the battery’s capacity. If you discharge from 75-65%, then you are using only 10% of the battery. So it’s important to understand what they mean by a DST cycle. If the mean the equivalent of 100-0%, then that gives one lifetime for the battery, but if they mean the discharge from 75-65%, then it needs 10 times as many charges to drive the same distance.

[@steviebeaton]

How quickly were they recharging the batteries (3kw, 7kw, 50kw)? As i understand it using rapid chargers frequently can prematurely shorten the life of EV batteries and wonder how this study was done.

[@MarksElectricLife]

Hi SB, The authors of the paper state that fast DC charging is not recommended and their results would not be achievable were you to charge at high speed on a regular basis. I would assume they were using AC trickle charging, below 20kW.

[@fluxcapacitor]

Once, I told about my experience in the smartphone world: the fact that in this case, a Li-ion battery retaining 80% FCC or below is considered "consumed" and must be replaced. I was told that the small batteries and electronics in a telephone were nothing like those of a car, and that my comparison didn't hold water, because IRL _it lasted longer than that in an EV!_ Now I see here an 3:50 that the EOL limit is not 80% but 90%! So it's actually worse! Are you sure that the graphics are for EVs specifically?

[@mikejoseph425]

I have a question. If I charge from 50% to 100% twice a week is that 1 or 2 cycles?

[@MarksElectricLife]

1 cycle

[@JohnHoffman]

I wonder if this study and recommendation is flawed. Reason I suggest that is because it is focused on the number of recharge cycles to degrade a battery. That is all fine but most people probably only charge the battery when it is depleted to a certain level. So for example if I use 10% of my battery for daily commuting. I could keep the battery at 60% and charge daily from 50%. That might get me 10000 days of use(recharges) before 90% degradation. However, if instead I recharge it when it is down to say 30% than while I might only get 5000 recharges I'd get 15000 days of use before 90% since I'm only charging every 3 days. Are there any studies that focus more on this kinda model? If I use 10kwh daily of my 100kwh battery what is the best charge/discharge levels to get the longest useful (90%) life?

[@chriswright2306]

Excellent info. Cars are increasingly using LFP and LMFP batteries, do u have research on these battery chemistry types. Thanks

[@MrStevegibb]

Storing your EV at storage voltage (60%) will prolong the cell life but !!YOU MUST PERIODICALLY CHARGE YOUR BATTERY TO 100%!! Every month at least or your battery will get wildly out of balance and also the BMS will have a tenuous grip at best on its actual state of charge. When you charge the battery to 100% to balance the battery pack allow a few hours after completion for all the balancing to complete but then you should ASAP use the battery to get it down to 80% or less at being stored at 100% is really hard on the cells.

[@thomaseynon6205]

Curious question. What if I keep it at 90%, but use less than 10% daily? Would maintaining a higher range be beneficial, it the battery was kept within a 10% charge (low to high)?

[@MarksElectricLife]

Hi, that is not recommended as it means the battery will sit overnight at a high state of charge. Much better to choose a maximum that is appropriate for the amount of energy you use daily. So, if you only need 10% then you could probably set your max charge to 60% and only increase it when you plan a road trip. The occassional charge to 90-100% is actually good because it allows rebalancing of the cells. But you should never charge above 80% and then leave the car to stand for long periods, or even overnight.

[@thomaseynon6205]

@@MarksElectricLife thank you very much for taking the time getting back to me. I really appreciate it. I will make the necessary adjustments moving forward. Being a first time EV owner, your videos on the matter have provided an incredible wealth of knowledge. Thank you!

[@MarksElectricLife]

@@thomaseynon6205 No worries Thomas! Just check what type of battery is in your car. This advice only suits the NMC ternary-type battery chemistry and doesn't apply to the newer lithium iron phosphate chemistry. There is some evidence that the LFP batteries can develop memory like old NiCd batteries (though not as bad) if not fuly charged and discharged.

[@thomaseynon6205]

@@MarksElectricLife From the information I found, the battery is said to be Lithium Ion NCM9 (rather than NMC), which from what I gather - identifies to have a lower Iron impurity. I ended up purchasing the 2023 F150 lightning XLT (standard range) about two weeks ago. Attempting to find any battery specs has been a task, to say the least. I ended up looking up who makes the f150 Battery (South Korean based SK On Co, also known as SK Innovation), which has then provided a bit of clarity. Being a longtime gas and diesel owner over the years, I have a lot of catching up to do, from a vehicle learning standpoint. But on a fortunate side of this subject, my career is surrounded around Cathodic protection technology, which helps me with a decent understanding of the relationship between the Anode, Cathode, Electrolyte, and Metallic path (aka - inner workings of a battery). By taking a moment to realize how to achieve adequate Cathodic protection (in my profession) on an impressed current and/or Galvanized CP system, the answer should have been starring me in the face already (hehehe). While protecting a structure, it’s important to utilizing the lowest affective amperage to prevent/slow the rate of corrosion, in order to maximize the life of a given CP System. Somehow translating this logic into an automobile, it created a mental block. Still very intriguing nonetheless, and I am eager to continue researching the technology of my most recent purchase. And once again, thank you for providing all of us with your knowledge/expertise. Your time taken has provided a world of value for many of us around the world. I look forward to more of your videos, as you’ve now gained another loyal subscriber.

[@Ravroid]

I have a newer Tesla with an LFP battery. Tesla instructs owners to charge to 100% for battery calibration purposes at least once per week. But I charge it to 80%, then once per week I charge to 100%. Is there a more optimal charging strategy to maximize battery life? Is 75% to 100% better?

[@pauld3327]

You're doing great. Don't charge up to 100% everyday, even with an LFP battery

[@manfredo4287]

What is a DST discharge cycle? 75-65 is smaller than 85-25. Than you will need much more cycles to do 100000 km?

[@MarksElectricLife]

DST = Dynamic Stress Test. 10 x 75-65 cycles = 1 normal charge cycle

[@haydenwhite2413]

So does each cycle represent only the difference between the two SoC? Meaning the green line is a 50% charge, and yellow is 10%? If so, I guess the actual miles driven would be a less dramatic difference. You may get 6x the number of cycles, but each cycle represents 1/4 the number of miles, so to speak. Still a benefit in longevity, but not 6x the number of years. Or did I misunderstand?

[@MarksElectricLife]

Hi Hayden, you have read the chart correctly. However context is important here. The car manufacturers, like Tesla, advise owners to plug their car in every day and indeed leave it plugged in overnight. This means the battery will be cycled once every day, regardless of it's SOC. Now, consider two owners, one who follows the yellow/orange line (Driver 1) and the other, the green line (Driver 2). To keep it simple, assume they both use 10% of the battery's capacity each day for their daily commute. Driver 1 has set his maximum SOC to 75%, meaning his battery will remain between 75% and 65% SOC most days (except for the odd long trip away from home). Driver 2 has set her maximum SOC to 85%, meaning her battery will remain between 85% and 75% SOC on most days. After 1 year, both cars have been cycled 365 times. Both cars have travelled roughly the same distance. However Driver 2's car battery will be more degraded by virtue of the fact that it has spent more time at a higher SOC. Bear in mind that the optimal SOC for any lithium ion battery is around 50%. The further away from that "Goldilocks" value, the more stress you put on the battery.

[@colin1992]

I have a 2024 Kona electric limited with 260 miles of range full charge I run it to 20% then back up to 80% which is 200ish miles, Yeah 100% would be nice but I want to extend my battery as much as possible

[@stevezodiac491]

you are just admitting by that statement that lithium ion batteries are flawed. Degradation will happen whatever you do or don't do, it will degrade just sat there in the garage doing nothing. My EV has lost 33% now in 8 years and only 40 k miles, very dissapointed.

[@grahambate1567]

A point not made is that the range of the ev is increased with more charge, chart should be skewed to show this In other words 100 percent from 25 percent gives a 75 percent range, but a 75 percent charge from 65 percent will only give a range of 10 percent, which is 7.5 time's less

[@doncooper2344]

Just to flesh out two other points made in the comments. The first point is that the life of a battery in years, based on cycles, depends on the capacity of the battery in kWh (or miles/km). If you have a battery that will power a vehicle for 300 miles, then 2000 cycles equals 600,000 miles. Vehicles aren't designed to last that long. No real point in having a functioning battery after a million miles when the vehicle will have been recycled long before then. (In the comments you say the number of charge cycles is based on the depth of the charge cycle -- so 100 cycles at 10% equals 50 cycles at 20% -- but I've never seen the data presented that way. A cycle is always from fully discharged to fully charged. IOW 10 charging cycles with a DoD of 10% is one cycle. It's why batteries in hybrid vehicles are subject to more abuse than batteries in BEVs). The second point is that a steady diet of shallow charge and discharge cycles will compromise the ability of the vehicle to estimate the capacity of the battery pack. As you know, the voltage drop over the cycle is fairly small. Since cells in the pack have to be balanced, the balancing will occur either at the bottom or the top of the discharge cycle. Sometimes both. If the discharge and charge cycle is very shallow, as you're advocating here, the vehicle will lose track of where the bottom and top actually are. It will estimate the battery has discharged long before it has, and estimate the charge has reached the top long before it has. The result will be a significant drop in the estimated range of the vehicle. Consequently, tossing in an occasional deep discharge and charge cycle is not a bad thing. FYI I don't know of any OEM recommending a battery be charged to 85%. I've only ever seen 80%. In the case of LFP batteries, Tesla recommends charging to 100% (unclear if this is every charge or once a week), but this seems to related to the calibration of the 12v battery rather than the health of the battery. (But yes LFP batteries will tolerate being charged to 100%).

[@petronelluigi]

Is there a video for high mileage drivers? I'm talking about roughly 700-800 km per week.

[@pauld3327]

LFP is probably better for those drivers

[@lenimbery7038]

I've been charging from 70-30 but will switch to 70-50....of course your charging cycle numbers will grow substantially ....but then again it's thousands which would cover far more time than I expect to own the car!

[@hizlimax]

You are missing on the number of charge cycles. You will create so many more charge cycles doing 50-60 everyday compared to for example 20-80 everyweek. The more charge cycles you create the quicker your battery will die.

[@scottwylde8528]

This is number of charge cycles. Not the number of miles driven! If you charge the battery 10% every day (and the battery is good for 7 times as many charge cycles) it is still lasting exactly the same as the battery that you charge 70% once per week. Same state of health, same number of years of service, same number of miles driven. But a big difference in the number of charge cycles.

[@MarksElectricLife]

That matter is addressed in my pinned comment - please read it. The real takeaway is don't leave your car charged to a high SOC overnight, especially if you don't need that high level for your daily commute. By only charging to the level you need your battery will be in better shape and hold more energy on those occasions when you do require a full charge, for a long journey. Even if you plan on selling our car after a couple of years it's quite likely the person buying it will want to do a battery test and they are more likely to give you a good price if the battery isn't significantlyt degraded.

[@netikraskanalas3565]

What is a cycle? if one Cycle is 65-75discharge then cycle is only 10% of battery, 85-25 is 60% of battery in that logic former cycle should be counted every 6 cycles of the first, maybe I missed something

[@superdidom84]

Interesting stuff. However a cycle is not equivalent to any cycle. 100 to 25 is a 75% capacity cycle, and it is equivalent to 7,5 times a 75to65 cycle (10%) If you use a cycle everyday VS use a cycle every week, counting them as "a cycle" in both cases is kind of misleading, init?

[@hbnhacthinhphongpiano5217]

Some time charge 10% to 90% for one month . 20% to 80% is good time for your time $ and Battery life

[@Parture]

The reason I would not go to 60-50, but 75-65 is because I am not always ready to recharge. I might be doing something else that occupies my time.

[@mariomedina]

It is better 75/45 or 75/25, less cycles but a lot more kilometers

[@Parture]

@@mariomedina I feel like I am always charging with a 75-65 configuration. To fix that I agree with you 75-25 is preferable even if the battery itself won't last as long by doing that. Mind you I do that anyway because I might be too busy doing other stuff to care about exact charging cycles.

[@Parture]

If 80-10 is the right amount for cars it should be the right amount for your phone.

[@jjamespacbell]

Data is incomplete as modern BEVs have a Battery Management System that is specifically designed to prolong battery life. Data from Tesla's battery expert Jeff Dahn flattens out above 90% through 250,000 km. What no one has real world data on is how BEVs with BMS will perform after 10 years and >500,000 km, time alone will tell. IMHO BEVs will last twice as long as ICE vehicles and be scrapped more because of newer technology (full self driving for example) and possibly newer safety standards than being worn out. This will lead to replacement newer car sales of all types of vehicles dropping dramatically as cars will be passed through generations.

[@ahbushnell1]

My vendor does not say charge to 90%.