Battery Life Expectancy

Aptera Community Aptera Discussions Battery Life Expectancy

Aptera Community Aptera Discussions Battery Life Expectancy

  • Battery Life Expectancy

     Stefan Obel updated 1 month, 3 weeks ago 23 Members · 35 Posts
  • Arthur Pina

    Member
    February 20, 2022 at 12:35 pm

    What is the lifetime of the batteries

  • Len Nowak

    Moderator
    February 20, 2022 at 12:57 pm

    They are still finalizing their batteries so I doubt they have warranty spec yet.

  • Jacob Bunce

    Member
    February 20, 2022 at 1:03 pm

    The lifetime is basically a function of the mile range of the battery. A 1000 mile aptera battery will last twice as long as a 500 mile lucid battery. This is because you only have to charge the battery (cycle it) half as often because of the larger “mile capacity”, and those cycles are what wear down a battery. So if the 500 mile lucid lasts for 200,000 miles between battery replacements, then the 1000 mile aptera should last for 400,000 miles between battery replacements.

    Under the hood, the two batteries are actually identical (100KwH). But aptera’s 100% higher efficiency consumes that energy less than half as fast, so less actual battery usage per mile = higher battery lifetime in miles.

    • John Malcom

      Member
      February 20, 2022 at 3:10 pm

      Not quite that simple to calculate.

      Other significant factors include battery chemistry, number of times charged in a given timeframe, type of charging (Fast DC, Level I or Level II) charge profile (Charge to % and charge depletion %) climate/weather, approach to heating and cooling the battery, and certainly the miles driven.

      We will get a battery warranty (As every other EV manufacturer provides). Up to this time you could reasonably count on a ten year battery life without significant degradation. Aptera’s battery configuration is innovative, so we should not judge Aptera batteries by existing examples.

      • Jacob Bunce

        Member
        February 20, 2022 at 4:28 pm

        Sure. But all other things being equal (chemistry, wear level, type of charging, etc), the same kWh battery in an Aptera versus a Lucid or Tesla will have double the life. Those other factors all cancel out if you just assume the same battery and conditions.

        Then you can start to make accurate approximations as to the life. A 200,000 mile battery life is achievable in those other electric vehicles. So just double it for a vehicle like the Aptera which is twice as efficient. Again, the “double” scenario assumes the 1000 mile Aptera because that has the same actual battery (in kWh, all things being equal) as a high end Tesla or Lucid.

        • John Malcom

          Member
          February 20, 2022 at 5:00 pm

          I think we will have to agree to disagree. All things are not equal and don’t cancel out as they are in separate random distributions each with a different variance by vehicle, battery, environmental conditions etc.

          I guess if you don’t want to account for the detail in the factors you can make a sweeping generalization. All moot I believe since we are getting an Aptera and it will be what it will be for us regardless of what other manufacturers put in their vehicles.

          I drive a Tesla Model 3 as do many of my colleagues. For us, there is a significant difference in battery longevity at the .05 level for our Teslas even after controlling for configuration variables.

          We are all kind of geeky and do this kind of thing for fun as well as professionally for an EV manufacturer we work for

  • Gary Greenway

    Member
    February 20, 2022 at 3:56 pm

    Aptera has stated that they are looking at 21700 NMC cells to build the battery packs with. So we have some clue on how to treat the batteries regardless on what brand cells they use. It is impossible to predict how long your battery will last. Battery cycle life can only be predicted for standard test conditions. The NMC sub-chemistry is frequently rated to retain 80% of its initial capacity after 500 cycles. A cycle is charging and then discharging the cell to 100% of it’s capacity. (Thank you Joshua Rosen for correcting this). Cycles less than 80% will increase battery life. So, to increase life, don’t fill it up to full and run it to empty before you recharge it. The shallower the discharge, the better. Charge and discharge current rates also affect longevity. To make a long story short, charge it every day or two after using it. Level 1 charging is fine. If you can’t charge it in a garage, get the full solar package to charge it for you. Additionally, the size of the battery pack affects how long it lasts. One cycle on a 25 kWh pack is 25 times 80% or 20 kWh usage. At the rated efficiency, that would be 200 miles. One cycle on a 100 kWh pack is 100 times 80% or 80 kWh usage. At the rated efficiency, that would be 800 miles. Of course real world numbers will be substantially less due to HVAC use, topography traveled, traffic conditions, overloading the measly 500 lb rating, and hot rodding it. Just remember, even after 500 cycles the battery will operate fine, it just won’t take you as far between charges. Once Aptera builds and tests the batteries, they’ll program the BMS to keep the cells healthy. They should also provide owners with specific tips to increase longevity for their batteries.

    • This reply was modified 4 months, 2 weeks ago by  Gary Greenway.
    • This reply was modified 4 months, 2 weeks ago by  Gary Greenway. Reason: Fixing incorrect info
    • John Malcom

      Member
      February 20, 2022 at 4:37 pm

      Good Discussion/ information

    • Joshua Rosen

      Member
      February 20, 2022 at 4:48 pm

      Gary, one quick correction. Charging to 80% will extend the number of cycles to about 1000. The 500 cycle rating is for charging to 100%. Depth of discharge also matters, doing 100%-0% is awful for the battery, 100%-0% will reduce life to about 300 cycles. Those are both numbers from several years ago, the durability of batteries has probably improved since then and of course it will depend on the manufacturer. Judging from a video that Aptera put up a couple of weeks ago it sounds like they haven’t locked in a supplier yet.

      • This reply was modified 4 months, 2 weeks ago by  Joshua Rosen.
      • Gary Greenway

        Member
        February 20, 2022 at 6:14 pm

        Joshua, I’ll gladly accept that correction on the cycle definition. Especially when it works out better for us.

      • Rob Spruijt

        Member
        February 24, 2022 at 1:00 pm

        So 500 cycles seems like a reasonable lower estimate? On a 1000 mile range battery that would be equivalent to 500,000 miles, if I understand you correctly. That would easily fit with Kaleigh (below) mentioning a ten year warranty. I think we’ll be good.

        • Joshua Rosen

          Member
          February 24, 2022 at 1:46 pm

          Most battery warranties use 30% as the acceptable degradation over the life of the warranty. Aptera’s exceptional range will provide several benefits that aren’t available in other cars. The first is that even with a 50% degraded battery you’ll still have a lot of range. The 600 mile version will be able to do 300 miles, that’s as much almost as much as a Model 3 AWD. The 400 mile version will still have 280 miles at 30% degradation and 200 miles at 50% degradation, that’s more than most new EVs today.

          The second benefit is that you can keep the charge level at 50% for most non-roadtrip driving. 200 miles is more than enough for almost all local driving which is what you’ll have with the 400 mile version, the 600 mile version is 300 at 50%, that will cover your whole metropolitan area. If you keep the wall socket level to 50% and then let the solar cells bump it to 75% max then you should get more that 1000 cycles.

          The final benefit is the one I already mentioned, the total number of miles in the battery is extended by 2-3X over lower efficiency vehicles.

          Usage won’t wear out an Aptera battery. Time might, time kills everything. The only other thing that could kill it is bad thermal management like the Nissan Leaf. Nissan used passive cooling in the Leaf and in hot climates the Leaf’s batteries got cooked. Aptera is going to have active thermal management so that shouldn’t happen but if they miscalculate the capacity of their cooling system that could shorten the battery life, I seriously doubt that they will get this wrong but it’s always a possibility.

  • Francis Giroux

    Member
    February 20, 2022 at 4:51 pm

    If I drive twice a day and leave my full solar Aptera in the sun the rest of the time, am I not going through 730 charge cycles a year without ever plugging it in? True, each cycle is not very long, less than twenty miles each drive, and likely uses only 10% of the charge state difference (250 mile range battery), and likely keeping the state of charge between 60% and 40%. Is this going to be good or bad for my battery bank? I’m assuming it’ll be good because I’m assuming that the real wear and tear on the battery is done when you get it almost full and when you run it down to almost empty. From what I’ve read the most damage is done on the high end of charge and running it down is not so big a deal. Am I wrong? I’d hate to wear out a battery bank in one year just doing what Aptera is advertised as being able to do (charge only from the sun). Does anyone have any industry information on the approach?

    • Joshua Rosen

      Member
      February 20, 2022 at 5:02 pm

      Keeping the battery in the 40-60% range is the absolute best thing for the battery. A cycle is not defined as charge then discharge it’s the 100% amount of the battery. If you have a 60KWh battery they a cycle is using 60KWh. If you always keep the battery in the 40-60 range then I’ve seen papers that say you’ll get around 1500 cycles which for a 60KWh battery is about 90,000KWh or 900,000 miles if you use the 10 miles per KWh figure.

      BTW the extreme efficiency of the Aptera should translate directly into longer battery life. The Aptera is 2.5X the efficiency of a Model 3 which means that the life of the battery should be 2.5X as much as the same size battery in the 3. Of course Aptera is offering a battery range that goes from much smaller than the 3, 25KWh, to much larger, 100KWh. Assuming Aptera does a good job of thermal management that means that the 25KWh battery should last almost as long as the 75KWh battery in the 3, the 40KWh battery will last significantly longer than the 3’s battery.

      • This reply was modified 4 months, 2 weeks ago by  Joshua Rosen.
      • Curtis Cibinel

        Member
        February 20, 2022 at 6:03 pm

        Interesting point. I hadn’t considered the efficiency impacting battery longevity. While I still think LFP for the lower range models would be a great upgrade perhaps the issue is overstated when looked at in a hyper efficient car. In effect the base model would likely degrade roughly on par with a model 3 (which is by no means unreasonable) and anything longer range would extend this by ~60%, ~160% and ~300%. 1000 cycles doesn’t sound like much but with 1000 mile vehicle that is a 1 million mile battery.

        PS: Really interesting to hear Chris mention LFP in the meeting. I honestly don’t understand why he thinks people would expect a discount with LFP given the other advantages. If the body of the aptera is designed for 100kw NCA battery it should have plenty of space for the less compact LFP batteries for the lower range options. If applied to the 250, 400 and maybe 600 (might be pushing it) mile versions it should be viable. As he said its 20% weight disadvantage at the pack level so assuming the current pack is in the 10-15 lb / kwh originally this is 50-75 lb, 80-120lb and 120-180 lb. The extra weight will hurt efficiency but 2-6% less efficiency is still not unreasonable given aptera is starting with such an amazing (3+ times) efficiency advantage compared to anything else.

        • Joshua Rosen

          Member
          February 21, 2022 at 9:01 am

          They’ve done their design with 2170s. LFPs are usually packaged as blades or pouch cells, don’t know if anyone has an LFP 2170. They don’t have the time or the money to rethink the battery pack at this point, maybe in a couple of years after they’ve gone into production. In the long run LFPs would make sense for all but the highest performing EVs. LFPs are significantly cheaper than NMCs, their downside is that they are heavier and they put out less current. Lower instantaneous power is a complete don’t care for Aptera because the power demands are massively lower than for any other EV. The weight will effect efficiency a little bit but given that they’ve designed the car to handle a 100KWh battery there shouldn’t be any other problems caused by the weight if LFPs are used in the smaller pack sizes. One more issue with LFPs is that they are harder to manage than NMCs because they have a much flatter voltage curve and they are more cold sensitive. Last year in Europe the LFP Model 3s had absolutely terrible winter charging performance, Level 2 speeds on a SuperCharger. Tesla has fixed the software since then and Bjorn has reported that the LFPs 3 are now charging faster then the older NMA SR 3s. The point here is that even Tesla didn’t get charging on LFPs right out the chute, they were able to fix the problem with an OTA but it took them an extra year. Aptera doesn’t have Tesla’s resources so they need to choose the simpler engineering solution first and put off the harder one until later.

          • Curtis Cibinel

            Member
            February 21, 2022 at 12:14 pm

            I completely agree that LFP shouldn’t be a focus yet; attempting it too soon could endanger the company at this startup stage. It is a transition that could happen after they start shipping the current model at scale (including 1000 mile for PR headlines) and can focus engineering resources. Perhaps the engineering effort will be part of the sedan project then later backported. LFP batteries are cheap, safe, less environmentally destructive, and aren’t touchy about charge percentage; this is too many advantages to ignore long term.

      • seth feldman

        Member
        February 24, 2022 at 8:01 pm

        “BTW the extreme efficiency of the Aptera should translate directly into longer battery life.” I disagree. Efficiency will translate to replacing a smaller battery for a given range, and hopefully cheaper(depends on manufacturing cost though). The actual range is what I expect to affect the percentage of battery used, and therefore cycles. I suspect the solar panels could give many people enough boost to keep the battery in the more optimal range between home chargings, if they even need home charging. The biggest questions I have is what the best charging routine/settings to baby their specific chemistry, and how does time effect the chemistry? These could be like the old prius batteries where high miles/charge cycles didn’t really effect them, but they started dying after 10-15 calendar years (I hope not).

    • Peter Jorgensen

      Member
      February 21, 2022 at 7:57 am

      I don’t think so, One charge cycle is 80kwh on a 100kwh battery if you’re using the 0-80%, 1000 cycle life rating?

      So you can charge 10kwh (100 miles) 8 times and that’s one charge cycle.
      Or you can charge 1kwh (10 miles) 80 times and that’s one charge cycle.

      Right? Correct me if I’m wrong here. I’m trying to learn also.

      • seth feldman

        Member
        February 24, 2022 at 8:37 pm

        100% charge/discharge is a complete charge cycle 100kwh in your example. not sure what you mean by 0-80%. depth of discharge maybe? A 10% (10kwh) dod would take 10 charges for a complete charge cycle. A 50% dod would take 2 charges for a single charge cycle etc….

  • Kayleigh Venne

    Administrator
    February 23, 2022 at 12:05 pm

    Hi everyone! Many cells can fail in our pack design before things need to be replaced. And if replacement is needed you would only need to replace the pack itself. The replacement costs will vary but be far less than any other EV as our packs are smaller for a given range. We will strive to make them affordable for upgrades in the future. You will not have to worry about replacing the battery or battery cells for at least 10 years. We expect to offer a 10-year warranty on the battery pack and for the battery to live much longer than that. More exact figures will be shared prior to launch! Thank you for all being a part of our movement to transform the world of transportation into a less destructive and more creative place.

    • Adrian deLisser

      Member
      February 23, 2022 at 12:22 pm

      Thank you for the update, Kayleigh.

  • John Trotter

    Member
    February 23, 2022 at 2:01 pm

    Battery life anxiety seems to be overtaking range anxiety, yet we still have no car-specific experience. Calma, gente.

    From what I have noted in the 18 months I have had a BEV, actual battery life is varied and hard to precisely predict. Generally, “birth defects”, such as the Chevy Bolt, is a concern covered by 1) use of not-state-of-the-art technology and 2) warranty. Aptera’s 2170 NMC cells are not state-of-the-art. Aptera’s proposed 10-year warranty covers both birth and adolescent defects.

    Wear and tear failure is far too complex for non-specialists (like me) to predict with any sort of precision. Charging low and slow seems better than full and fast, but I’ve seen no specialist brave enough to quantify that effect. Does it range between 1% and 5% per year? Probably, but how controllable is it? The Aptera (solar) trickle-charger is excellent for “slow” and the car’s efficiency allows slow charging as a matter of course. There will seldom be need for medium (Level 2) or fast (DC) charging, but I won’t worry when it is useful.

    • Nathan Hubbard

      Member
      February 24, 2022 at 3:00 pm

      It makes sense to worry more about battery life than range, when the range on these vehicles shouldn’t be as much of a problem.

      I think the comment above about time being the biggest problem is quite accurate. These batteries are going to lose range as they age, even if you are careful with them, but hopefully in 10 years time replacing them, maybe even with an upgrade, won’t be so expensive as it would be now.

  • Edward Hernandez

    Member
    April 17, 2022 at 1:48 pm

    Hopefully this can still be seen. What effect does the solar charging have on battery life? I don’t know much about these batteries, but do they have the issue where constant charging lowers battery life? I believe the Tesla is suggested to drop to around 10% every time, then charge, to extend battery life.

    • Joel Smith

      Member
      April 18, 2022 at 11:13 am

      A few thoughts on that:

      Generally the lower the charge rate the lower the “wear” on the battery. The lowest L1 charge rate on a typical modern EV is going to be 1200-1600 watts (depending on your EVSE). The most you will get out of the current PV configuration on the Aptera is 700 watts. Pushing awful close to negligible there.

      We are liable to be able to set max SOC for charging off a plug and separately off the built-in PV so the user will be able to set those limits where they think prudent for their own battery degradation risk assessment.

      As an anecdotal example, my Leaf has about 130k miles on it with minimal battery degradation (and everyone thinks Leaf batteries are the worst). My Aptera will have a 40kWh battery instead of a 24kWh battery and go 10 miles per kWh instead of the 4 my Leaf gets. A little math informs me that my Aptera might suffer a similar amount of battery degradation after 541,667 miles. I only drive about 20k miles per year. That’s rather more than the US average. Somehow I’m just not that worried about battery degradation (at least due to moderate charging practices) and doubt that anyone else should be either.

      • Joshua Rosen

        Member
        April 18, 2022 at 11:42 am

        I’ve said this before but I’ll repeat it again so that someone at Aptera will see it. As you said there needs to be two charging levels in the Aptera instead of the one that ordinary EVs have. A max charging level and a plugin or minimum charging level. The max level is to protect the battery, you would typically set this to 80-90%. The plugin level, or minimum level, limits the charge from the EVSE. You would want to set this level the lowest level that will give you a comfortable local range. For example in the 400 mile version you would set it to 45% which is 180 miles. That leaves the space for 18KWh of solar energy. The 60KWh battery would be set to a minimum of 30% (same 180 mile range) leaving space for 36KWh of solar.

        • Jonah Jorgenson

          Member
          April 18, 2022 at 3:41 pm

          I really think the power engineers at Aptera understand charging pretty well and, as their focus dictates, will engineer the charging system to achieve the most efficient (for charging and battery life and other factors we are not aware of) design. Let’s let them do their work.

  • John Fowler

    Member
    April 26, 2022 at 8:52 am

    I may drive the Aptera 400 miles on a charge. At 60 mph that’s more than I can drive in a day. I stop at an RV park, pull out my Aptera tent (or whatever they call it) and plug in the Aptera. The next day I’m charged up for more travel.

  • John Shenton

    Member
    May 16, 2022 at 8:43 pm

    What about the folks that drive less often. Vehicle sits for three weeks at a time (vacation etc.)?

    Would keeping the battery cooler than normal lighten it’s life span?

    • kerbe2705

      Member
      May 16, 2022 at 10:17 pm

      @John Shenton Lithium batteries can sit partially-charged for a very, very long time: What you don’t want to do is to fully charge or fully discharge them and then leave them sitting… They seem to be most comfortable in mid-70°F temps – so too cold or too hot make them equally uncomfortable. Think “Goldilocks” and you’ll understand the “care and feeding” of lithium batteries.

  • David Marlow

    Member
    May 16, 2022 at 10:22 pm

    Battery life expectancy is dependent on many factors, the most important is the battery management system (BMS) built into the vehicle and how much control it actually has of temp, charging and discharging. Assuming that the BMS can control all of the factors at all times, the battery should last at least 10 years (while retaining at least 80% capacity), regardless of the number of cycles one will actually do. Actually the battery the battery should remain useful down to 60% or less capacity, so maybe 20 years. The cycle life calculations are done under ideal conditions and even the best practical BMS can not guaranty this. Temp., time, charging and discharge control are the major factors in actual use.

    • Curtis Cibinel

      Member
      May 16, 2022 at 11:31 pm

      Based on stats from teslas with 2170 (and similar 18650) cells it is probably reasonable to expect that less degradation will occur. 20% in 10 years would probably require some suboptimal temperatures or full cycling. Most 2170 cells are rated for 500-1000 full cycles to 80%. The buffer (about 6%) and staying mainly in 20-80% further extends life. Very likely a 400 mile Aptera won’t hit 80% battery until 200k miles or more.

  • David Marlow

    Member
    May 16, 2022 at 11:23 pm

    Regarding battery warranty, I think that with the 25KW battery they should be able to go 10 years or 120K miles.

    The 40KW battery 10 years or 150K miles.

    The 60KW battery 10 years or 200K miles.

    The 100KW battery 10 years or 300K miles.

    The increased warranty for the larger batteries is mainly due to less stress during charging and discharging. Also you should get some reassurance for purchasing the larger battery size.

  • Stefan Obel

    Member
    May 17, 2022 at 5:07 am

    Here’s some real-world data about the battery degradation of my TM3LR.

    We got the car on 8/16/21 and yesterday (5/16/22) it turned 9 months “old”.

    During that time we’ve driven the car 30,229 miles with a total of 304 regular AC charges adding 8,090 kWh and 20 times using a supercharger adding 436 kWh.

    Compared to the “fleet” (Teslafi using other TM3 with similar odometer reading) at 30,229 miles our TM3 has a now a “rated range” of 341.97 miles while the fleet average is 330.34 miles.
    This also proves that driving a lot is certainly NOT a death sentence for a battery as many anti-EV folks wrongly claim – unfortunately such non-sense gets stuck in the heads of the uninformed.

    My starting range was 345.77 – resulting in a range loss of 3.8 miles or 1.1 %

    Good “charging habits” seem to make a huge difference and have a huge and quick impact on battery life. My spouse was in charge of charging while I was gone for 2 weeks starting around 27k miles. The range of our car dropped below the fleet average during that time.

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