Tesla Model S Battery Teardown

Tesla Motors club user [wk057], a Tesla model S owner himself, wants to build an awesome solar storage system. He’s purchased a battery pack from a salvaged Tesla Model S, and is tearing it down. Thankfully he’s posting pictures for everyone to follow along at home. The closest thing we’ve seen to this was [Charles] tearing into a Ford Fusion battery. While the Ford battery is NiMH, the Tesla is a completely different animal. Comprised of over 7000 individual lithium-ion cells in 16 modules, the Tesla battery pack packs a punch. It’s rated capacity is 85kWh at 400VDC.

[wk057] found each cell connected by a thin wire to the module buses. These wires act as cell level fuses, contributing to the overall safety of the pack. He also found the water cooling loops were still charged with coolant, under a bit of pressure. [wk057] scanned and uploaded high res images of the Tesla battery management system PCBs (large image link). It is a bit difficult to read the individual part numbers due the conformal coating on the boards.

A second forum link shows images of [wk057] pulling the modules out of the pack. To do this he had to chip away the pack’s spine, which consisted of a 2/0 gauge wire potted in some sort of RTV rubber compound.

We’re sure Tesla doesn’t support hackers using their packs to power houses. Ironically this is exactly the sort of thing Elon Musk is working on over at Solar City.

81 thoughts on “Tesla Model S Battery Teardown

  1. at over 100,000 dollars for the original tesla car and i dont know much for the latest model(s) it took some major courage to tear down the battery and the cars are too expensive and too dangerous to be in a junk yard.

    teslas that people have no one wants to take tools to their car and would be very careful to avoid an accident and any that are totaled probably has the batteries removed because of fire risk.

    maybe mr musk probably is not as secretive as the previous ceo/owner.

    the next thing if it was bought on ebay or some auto shop that upgrades batteries then the hazmat fee would be quite high for shipping

      1. someone who is very rich say bill gates maybe but the rest of us that is the cost of a house and most of us have to take out a loan to buy a car at a fraction of that price.

        whenever you ship lithium batteries of greater than 50 watt hours (i think) it requires dangerous goods labeling and an extra fee.

  2. “These images may not be copied or otherwise distributed outside of this forum without my express permission.”
    If you obtained permission to repost his image you should mention it.

        1. I have. You should probably do the same.

          Fair use is a limitation and exception to the exclusive right granted by copyright law to the author of a creative work. In United States copyright law, fair use is a doctrine that permits limited use of copyrighted material without acquiring permission from the rights holders. Examples of fair use include commentary, search engines, criticism, parody, news reporting, research, teaching, library archiving and scholarship. It provides for the legal, unlicensed citation or incorporation of copyrighted material in another author’s work under a four-factor balancing test.

          1. Try actually reading past the the 1st paragraph from wikipedia. Maybe attemping to understanding what the words mean or… even venturing beyond wikipedia.

            I should stop feeding trolls tho.

    1. You can recycle lithium batteries, just like lead acid batteries. The infrastructure is not really in place right now but I would imagine in a pinch your local municipal dump would accept them if you happened to have a pack that you wanted to safely dispose of.

    2. Safety? People will just throw it away like motor oil, flourescent tubes and all the smaller consumer batteries. Almost nobody actually cares. Self-righteous loudmouths commenting on this comment will, but how many actually go out of their way and pay extra to safely dispose of every single CFL and every single lithium battery. Mabe one. Maybe. Practically speaking, lithium batteries will go with NiCd’s and mercury vapor lamps straight to the dump.

      1. I make it a point to take my spare CCFLs, fluorescent lamps and batteries to my local hardware store. They have a free turn in program and I am already going there anyway. As long as it is not for business use, my local municipal dump will take hazardous materials and even if it is for business use, as long as you qualify as a CESQG, you can take it there for no charge too. I hope I am not the only person who recycles.

      2. I recycle my CFLs, oil, batteries etc. for free at the hazardous materials center at my local dump. So there are at least two of us :-) I collect the materials in the garage and then take it all to the dump about once a year when the old lawn mower gas needs disposing of.

        1. Where I used to work, someone had thrown a car battery into the dumpster. When the driver went to crush it, it exploded and caught the truck on fire (Stunk to high heavan). Then he wasn’t able to dump it as we had a propane filling station in our parking lot. Luckily the fire department was able to put it out before the truck was damaged. I still see that truck years later with the burn mark in the paint.

          I couldn’t imagine one of these going off.

          1. The firefighters actually made it worse by trying to make holes into the battery pack so they could shoot in more water, instead of using the appropriate firefighting methods for such situations. The pack is designed to burn slow and has vents to vent out the hot gasses safely from the car so that they don’t burn into the cabin/rest of the vehicle, but these yahoos just went “we can’t get water into it! LETS MAKE SOME HOLES IN THIS CAREFULLY DESIGNED STRUCTURE SO WE CAN SHOWER IT WITH MORE FUEL!”

      3. My employer has recycling bins set up for any batteries we consume at work. Corporate has mandated that these bins are also open for use by employees to bring spent batteries from home to be recycled free.

        Not sure how they’d react if I tore down a used tesla battery pack and brought in a few buckets of dead cells, but it has been very convenient for me to dispose of the few batteries I consume.

        1. The re-use value of the battery pack may be thousands of dollars, but the actual value of the materials is only about $500 for the Li2CO3 – It’s not worth the danger/time involved to recycle them, but it may be worth someone’s time to repair and reuse the pack.

  3. Electric cars IMHO are not viable outside the subsidy just as the solar homes. Viability might occur when kilowatt hour becomes $0.50 and a gallon of regular goes for ten bucks, I do mean true market viability, no taxpayer schmoozing no games on the books.

    1. No, electric vehicles will only become viable to the general population when you can get a 200+ mile charge in less than 5 minutes and the battery has a lifetime of over 10 years (or are really cheap to replace). The tech exists in labs, manufacturing is catching up. But it’s not here yet, nor will be for at least a few years. Probably closer to a couple decades.

      A bigger concern is what those greedy politicians will do when their massive gas taxes start dwindling…. $0.15/kWh will turn into $0.40/kWh after [your government here] decides to “tax electric cars owners” to “make them pay their fair share”.

      1. I’d be suprised if a charge rate that fast could be achieved.

        I think what is more likely is a battery exchange station, maybe with solar panels on the roof. That’s the most realistic way of getting the convenience to the end user.

        1. The solar panels on the roof would make for nice decorations – you’re not going to pull down 50-75Kwh per vehicle from a gas-station-roof sized solar array. Your average Walmart-Supercenter-sized solar array might be able to do 50-75 cars per hour at high noon on a sunny summer day. Perhaps 240 cars per solar day.

          In this world, a medium sized gas station may sell 10k gallons per day. If we were living in a world where everyone drove Teslas, and still went to ‘filling stations’ to get all their energy, and still drove as much milage – that would be ~125 full charges per day.

          Long story short – Gas stations are going to have to get much bigger, if we’re all going to do solar powered centralized charging.

      2. “Superchargers provide half a charge in as little as 20 minutes”
        Which is 250km, not far off from your less than 5 minutes, and you can charge you car at home instead of needing to do fuel trips, so the time filling up total drops dramatically.

      3. Flow batteries are interesting, rather than trying shove stupidly large current into cells or get a robot to switch out packs you can just pump out the spent electrolyte and recharge it externally.

        I’d still want to be able to plug in at home though, the idea of just charging my car every night and having a full tank in the morning is really appealing. Assuming the car has enough range to cover a normal days traveling you wouldnt ever need to visit a charging station except on long trips!

        I’ll probably buy an electric car when they hit 100 motorway miles with heating on a single charge for less than £30k. Based on my current diesel spend I’d break even on a lease.

        1. If everyone in the neighborhood had electric cars, it would multiply the local electricity consumption. The problem is that everyone would try to charge their cars at the same time, which is usually 5 in the afternoon when everyone comes back from work. Doesn’t matter when exactly though, because they would still take 8-10 hours to do it, so there’s plenty of time for overlap.

          It’s like the problem in the UK where everyone turns their ~1 kW kettle on for tea after certain television programs – only much worse because it lasts for hours and needs 2-3 times more power.

          1. There’s two problems with adding loads to the grid — transmission/distribution and generation.

            WRT transmission, 5 in the afternoon might be a problem on a large scale, but anything later than that won’t be a problem at all. See, the grid is at maximum stress in summer afternoons (higher ambient temperature reduces the current handling ability at the same time A/C usage is maxed) — as the late afternoon/evening rolls around, the lines are cooling down, the A/Cs are running lower duty cycles, and industrial electric use is decreasing; the grid as a whole* has capacity to spare for some cars. By 8 or 10 at night, there’s no problem at all. It’s possible enough people will plug in later (after running errands and such) that it won’t be an issue — I wouldn’t bet on that, but we’ll see as EV use increases.

            *The final layer of distribution in residential areas may need beefed up, since charging an EV draws about twice the power of a central A/C unit, but this is a lot cheaper than the whole-grid upgrade many people assume EV uptake will require.

            If enough people do plug in straight after work to be a problem, the technical solution is simple: put timers in the chargers, such that they deliver a slower charge the first couple hours, then switch to full power (base it off an RTC, so if you’re out running errands for a couple hours after work and plug in at 7 or 8, it goes right to full power). The social solution, to persuade people to use the timing functionality instead of hitting the panic-charge button every time, is left as an exercise for the reader. Possibilities include new laws, appealing to their better nature to behave in the best way for everyone, or billing the same electric consumption at different rates depending on time-of-day — the last one is already done for industrial and some residential customers.

            WRT generation, OTOH, there definitely would be a problem if everyone switched to electric cars in the next year, because the peak demand (as mentioned, on summer afternoons) is handled by different, expensive to run, plants (typically natural gas turbines) vs. the far cheaper, but slow-responding, plants providing baseline generation — but since the peaking plants only run a small fraction of the time, electricity remains (relatively) cheap. (Actually, there’s several stages between base and peaking, with progressively faster response and higher cost.) If you suddenly add near-peak loads all night, the more expensive plants run more of the time, and the average cost of electricity goes way up. But this isn’t a problem if one considers realistic time scales of adoption — it will probably take 20 years before everyone in the neighborhood switches to EVs, which is time to expand the right sorts of generation to handle higher evening loads.

        1. About a year ago a number of (United) states were considering higher annual licensing fees for electrics and hybrids to compensate for this. I haven’t heard much since then, so I don’t know if it actually happened anywhere in the U.S.

      4. If I could power a vehicle at a tiny tiny fraction of the cost, it wouldn’t remotely bother me having to swap between two batteries.

        I also dont think everyone really needs cars for long journeys – most dont. Having a short range car (shopping kids) and an occasional long range one probably would make economic sense for a lot of people.

        As for the politicians – not much they can do if your charging off your own solar panels is it? And thats the direction Elon & Co are pushing. (of course, they want to sell us the batteries for the load balancing)

        1. Problem is that it would take “a while” to get the full charge of 85kWh from a single house with solar panels, you’d need a fairly sizable solar farm for it to be practical…

          A far more interesting idea is using the battery packs either in pure electrics or hybrids for the load balancing, that way more we could afford more nuclear (be it todays fission of far-future fusion) power generation, since there is a practical limit to how much energy production can come from nuke plants, because of the reaction time they have.

        2. I would consider swapping batteries to be an acceptable solution, provided it could be done safely, easily, and reasonably quickly.

          My difficulty with the current state of electric cars is, between distance, sitting in traffic, heating/cooling, etc., I estimate I would get _to_ work on a full charge but couldn’t guarantee making it home. My place of work does offer a limited number of charging stations but I’m not willing to count on one always being available, and if my home power went out for an extended period of time (a few hours overnight?) I’d be of luck. So until the technology improves, my best bet is gasoline or at best, a hybrid.

          1. You’ve not looked into Tesla it seems… I leave home every day with a full “tank.” I never ever stop for fuel on a regular basis. I take a 600 mile trip occasionally which requires a total of about 45 minutes of supercharging… enough for a quick dinner stop.

            Even if you lost power for a day or two at home, 265 miles is quite a bit… comparable to a tank of a lot of gas cars. Doubt you’d be stranded, and if the power was out at the gas pumps you’d be just as screwed anyway.

          2. @wizkid057, you’re right, I haven’t looked at a Tesla, mostly because from what I’ve seen (admittedly, not digging really deep) it’s way out of my affordability range. For example, from the Tesla Motors website (http://www.teslamotors.com/true-cost-of-ownership), even after taking all the savings into account you’re looking at $678/month at the lowest end. That’s on a 6 year loan with a 10% down payment and doesn’t even consider what it would do to my insurance rates.

            The performance you cite is impressive and comparable to what I get with my current vehicle. But until that price comes down to about $400/month on a 4 year loan, I’m afraid it’s just not going to happen.

        3. The two battery solution is not practical with Teslas, and probably anything else, the batteries are heavy and the Tesla battery pack is removed with a special jack beneath the supported auto. Granted, auto mfgrs could design a quick change pack into their EV’s but that would add to the already higher cost.

      5. > No, electric vehicles will only become viable to the general
        > population when you can get a 200+ mile charge in less than 5
        > minutes and the battery has a lifetime of over 10 years (or are
        > really cheap to replace).

        So you would prefer your mobile phone to be ethanol driven instead of lithium battery? It can be refilled within secs, instead of charged overnight.

        I hope you see your fallacy here.

        1. Ummm, except my mobile phone, and my car have very different uses, and thus very different needs.

          if my phone runs out of battery whilst I’m away from home, that is not a problem, whilst it is a huge problem if my car does.

          If i’m ever in a situation where I know that I will rely on my phone and would be stranded without it, I’d take a spare battery for an instant fresh charge…

      6. I’d drive electric if I could run for 200 miles, and charge for just 5 minutes. That would almost be like the America I knew. Back when you could just jump in your car and drive clear across the country, with hardly a care in the world. I guess if you’re really rich you can still do that today. There’s just something about knowing I’m going to get a $400+ gas bill at the end of the month that leaves me somewhat concerned today myself.

        Stops are what add to an ETA traveling though. So while 200 is nice I’d really like to see a 300 mile range myself. That is on par with a gas tank in an average car. Mercedes turbo diesel has a 600 mile range. You can really cruise in one of those!

        1. because your whole life revolves around something you have time and money to do MAYBE once a year…

          this is the stupidity of the “range” argument 99% of the time for 99% of people it wouldn’t matter if you had an electric car but you stuck on the one event where it would work as well but that’s all you can see. it’s almost as bad as your “the America I know” comment were you might we well be saying your too stupid to learn or enjoy new things.

      7. Yes, those greedy politicians, wanting people to pay for the public infrastructure they use. It’s just terrible isn’t it?

        As for your assessment of what will make electric cars viable for the general population: Lame. Most of the time, most US drivers would be served by 70-100 miles of range, or less, and overnight charging. Those who consistently need longer range and quicker turn around could use gas or LPG, and those who occasionally do could rent an internal combustion vehicle. Affordability is still an issue, but improving. Whether or not people make such adjustments as EV’s become more affordable remains to be seen, but its not unprecedented.

        Your analysis is like saying that automobiles will never be mainstream unless they can be steered with reigns, powered with hay and oats, and produce waste that can be used as fertilizer, because, after-all, thats what people expect of their personal transportation.

    2. great, keep on moving the goalposts to justify your inertia! 1 or 2 meters of seawater might also not be viable for you, but that will not happen, and if it did it bears no relation to your gas guzzling ways.
      In other words, the impetus for moving towards electric is not to be cheaper.

    3. LCOE of solar energy is 11 cents in 75% of the US (where each kW will yield around 1150 kWh/yr), which is about the average seasonally adjusted cost of utility electricity. This does not include the fees and taxes which, nationally are about 12%. Thus, solar energy is cheaper than utility energy at the retail level. The remaining barrier is essentially financing. Utilities get very cheap capital homeowners do not. So before bemoaning ITC, accelerated depreciation, or other state solar incentive programs, please inform yourself as to the regulated (subsidized) economics that have always worked to 1) subsidize bankers and middle men and 2) given consumers cheap energy.

      You can buy a complete equipment package for $1.20/WDC. Rack and wire it yourself, claim the tax credits and subsidies or leave them on the table. Either way you’ll still lower your energy cost just about everywhere in US.

    4. WTF are you smoking? Electrics are already cheaper to run than petrol cars; the only limiting factor is range and honestly that’s not a problem for people 99.9% of the time when they’re just commuting to work.

      If you were actually paying the true cost of carbon consumption instead of having politicians subsidise fossil fuel production through tax exemptions, petrol would cost more than it does in Europe, which is about 4x-8x what the USA pays depending on location. Wait until Musk gets to the scale of Halliburton and starts wielding a similar level of political influence; I suspect you’ll see the government-imposed market distortions start to move rapidly away from oil+coal and towards electrical infrastructure. Got nothing to do with environmentalism, just whoever has the most cash to buy politicians, but a cleaner environment is a nice side effect.

      Considering that it’s now cheaper to install new solar PV than it is to install a new coal plant (on the basis of lifetime-amortised capital plus running costs), electricity prices are only going to go down.

  4. I’m not so sure that Tesla would dislike people using their batteries for home storage. They’re building a battery factory that will produce far more than there is demand for at the moment. They want EVERYBODY to use their batteries.

    Now, I’m sure that they’re uncomfortable with people ripping their batteries apart. Idiots setting off a small bomb in their house is probably bad PR.

  5. One of the things I saw being pointless, was blurring the main battery pack serial number, and not also blurring the data matrix code to render it unreadable. The reason, is that the serial number of that pack also lives in the data matrix code.

  6. Ummm, except my mobile phone, and my car have very different uses, and thus very different needs.

    if my phone runs out of battery whilst I’m away from home, that is not a problem, whilst it is a huge problem if my car does.

    If i’m ever in a situation where I know that I will rely on my phone and would be stranded without it, I’d take a spare battery for an instant fresh charge…

  7. The ICs can be identified. I figured out the part numbers by just tweaking the contrast and brightness. Then I went to the thread and realized someone there had already done it. Yes, they are laser-etched, and yes laser-etch can be hard to read, especially with conformal coating, but if you do a little bit of work with a free image editor (paint.net is my choice) you can usually figure it out.

    http://www.teslamotorsclub.com/showthread.php/34934-Pics-Info-Inside-the-battery-pack/page27?p=755199#post755199

  8. I see a whole bunch of guys complaining about range etc etc. I vacationed in europe and actualy ended up buying a used diesel vehicle for the same price as renting one. The falacy here is that you need electric or hybrid vehicle. The diesel focus I bought got a consistant 5.2L/100km. which brings it inline with any prius/hybrid in the market. It has a range of about 900KM and produces about 113hp. Under my american heavy foot it got me a 47mpg with no range enxiety and low quality fuel. I put on over 1500miles in 3 weeks on that car. If that vehicle was available here I would snatch one up quick.

    You guys also seem to forge two things about people.
    1 – you can’t force people to automatically plug in every night, they will forget.
    2 – you cannot acount for emergencies while includiing an EV. I need to get the hell out of dodge quick, and guess what my battery is dead. Yay ev.

    Also the suggestion of having a non ev vehicle as a spare for long trips is idiotic for two simple reasons.
    1 – ice vehicles degrade faster when sitting than when driven
    2 – your negating all cost savings by insuring and maintaining a second vehicle that will be unreliable at best.

    Its cheaper to insure and maintain a single gas guzzler than it is to replace it with an ev and a secondary vehicle.

    Just get a fuel efficient non hybrid and drive that. It works out cheaper in the long term.

    1. ^THIS^

      Further, people seem to overlook the environmental impact of producing that fancy electric vehicle! Ever sit down and figure out how much energy is consumed, and how much industrial waste is generated when the electronics and the batteries for these things are produced? I think it would be an interesting research paper…LED and CFL bulbs versus Incandescent would also be an interesting study along these same lines.

      I get angry every time I see Nissan Leaf drive by with the ‘Zero emissions’ plastered on the back..Did you plug that in at home? You did! Where did that power come from? Unless you are living off grid, some of it came from a carbon emitting power plant somewhere on your power company’s grid! So much for the ‘Zero Emissions’. What a lie to sell them to consumers! I don’t fault the individual, as they want to do their part to help, but really?

      EV’s have a long way to go, but we are making steps in the right direction. I think the ultimate solution is going to be some kind of hybrid or fuel cell type vehicle, giving you the reliability of an independent energy source versus just a reserve or storage, and the ability to delver large amounts when needed, such as acceleration etc from a reserve.

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