If you read the press release, they are claiming they are the first to warranty capacity. Tesla, like everyone else, does not warranty capacity loss.
Note that the bars are not linear. This had us all puzzled, but according to the 2011 shop manual, the first bar is worth 15% and the subsequent ones are 6.25%. Tony summed it up thusly earlier today:
Tony Williams said:
But it's more nuanced then that. If all the bricks/sheets have lost capacity then yes, there is no warranty claim. But if a brick has significantly less capacity than the others (which drops your range as you can only drive as far as your weakest brick) then Tesla has replaced packs under warranty as the irregular drop implies a manufacturing problem whereas if they all go down together then the system is working correctly and you have simply used up the pack.
Actually, we don't want the state of charge expressed as a percent, at least not the way the LEAF does it. In the LEAF, the SOC percent is relative to the battery's current capacity, which changes on a daily basis with temperature, on a monthly basis with the seasons, and on a longer timeframe as the pack capacity degrades. It's hard to tell for sure, but I think the Roadster's charge gauge (and corresponding numerical values on the CAN bus) are relative to the capacity of a nominal new pack. Even better is the Tesla's display of the state of charge in absolute energy units: "ideal miles" on the Roadster and "rated miles" on the Model S.
Tom, thanks for your comment. There are two sets of bars on the battery gauge in the LEAF. Many owners are surprised when they learn about this. Please have a look at the photo below, which I took at the Phoenix range test. It shows a LEAF with a full charge, but with three capacity bars missing. If I'm not mistaken, this car came in with 80.1% of original capacity remaining during the test, although it should be between 66.25% to 72.49% battery health per the gauge. This is likely the type of error Andy Palmer was referring to earlier this year. The capacity gauge is supposedly non-linear to reflect a large drop early in life of the vehicle, which should then level off and be almost linear later.
Agreed. I would love to see a kWh estimate somewhere as well, if possible, much like what GM does in the Volt. Nissan has already confirmed that the 2013 model year LEAF will contain an SOC gauge in percent. Kadota-san directly attributed this change to a meeting held at Google last December.
The problem is if the capacity warranty is too low (if I'm understanding correctly, it's even worse than I mentioned in the previous comment, it only applies if you hit 66.24% or lower in 5 years/60k miles), it might make matters worse. People will assume that's how the battery will perform, even though the warranty only covers for the worse case (basically overlapping with the defect warranty which every company has).
Stopcrazypp hinted at it. It's just too complicated to spell out all the terms in our litigious society. Battery capacity depends on how the battery is used. Yes, Tesla does way more than anyone else to protect their batteries but there are still things a user can do to prematurely wear the batteries and Tesla would have to spell all of these things out in the warranty. How many times can you range mode charge per month? How long can it sit at a full range mode charge? How many times can you run it to zero or below? Spelling all of these things out would make people WAY more scared of buying an EV than what we have today where the warranty says the battery is covered for manufacturer's defects but not loss of capacity. ICE's aren't warrantied to have the same 0-60 or mpg 8 years after purchase, this is the same thing.
Yes, much will depend on implementation and interpretation of the warranty. Nissan gives every owner an annual battery report, which is supposed to be educational, and is based on detailed usage logs stored in the battery ECU.
I think the intent is to warranty 70% of capacity, much like GM does with the Volt. Typically, industry EOL criteria for a battery is either 70% or 75%, and this number is not too low in that context. Owners are asking Nissan to see if the threshold could be higher, we will know soon enough. I'm not a fan of the bars, and would prefer to see a numeric value in the center console. That said, Andy Palmer hinted at an upcoming software update, which should make the bars work well enough for the purposes of this warranty. It's an abstraction and a convenience, but presumably, once a LEAF has lost a certain number of bars, Nissan will bring it back up to spec. This will likely translate to a new battery in most cases.
You can't only look at threshold, you also have to look at years and miles. The Volt's warranty is 8 years / 100k miles (10 year /150k miles in California). Tesla estimates 70% in 7 years /100k miles. Of course those represent average case (Volt gives a vague capacity warranty that doesn't not set a hard threshold for replacement, it's up to the technician to determine; Tesla doesn't cover capacity at all).
Do you know if this will be a percent relative to the pack's current capacity (like the SOC bars) or relative to a nominal new pack's capacity (like the capacity bars)? If it's just a numerical representation of the the SOC bars, then it tells owners nothing about how their battery capacity is changing. Knowing your charge percent relative to a constantly changing estimate of current pack capacity is only marginally more useful than the SOC bars. I hope the Bay LEAFs meeting conveyed our need for state-of-charge in absolute energy units.
But to be in a warranty they will need to spell out EXACTLY what it takes to be in compliance. If they're going to deny anyone for capacity they will have to be able to point to what the person did "wrong" to cause them not to replace the pack. You didn't address my point that ICE's aren't warrantied to maintain performance (speed or efficiency) over time so how is this different? The only difference is that there is 100+ years of "common knowledge" related to ICE's but not EV's. So just like in the early days of ICE's people had to haul their own gas and sometimes get towed into a gas stations by a horse it was those pioneers that eventually made the ICE ubiquitous. EV's must follow the same adoption curve. People don't like change and short of a shooting war breaking out in the Middle East and gas shooting to $7+/gallon it's just going to take time.
If you lose charge in only one set of cells (and it's not a simple balance issue that can be fixed by balancing the pack charging it full), then that's a cell defect issue and is covered under the warranty (Tesla has replaced cells/slices for the Roadster because of this). If you lose charge evenly in all cells, then that's natural capacity loss and not covered (unless you have a capacity warranty).
Hi Tom, happy New Year, my apologies for the belated reply. I'm reasonably certain that the new SOC gauge will display just a percentage of current capacity, and not provide a measure of total usable capacity. While I agree with your POV, and several of us asked for a kWh estimate instead of another set of goofy numbers, it was difficult enough to convince the visitors from Japan that we did not find GOM estimates useful. What you see on the photo I referenced upthread is an informal survey, which was conducted to see if an SOC indicator was better than the current guessometer. We provided Nissan with a very detailed list of suggestions, and many items were compiled into a slide deck, which was translated into Japanese as well. There is a new section on the MNL wiki for product improvements and driver feedback: Lists of driver feedback - MyNissanLeaf
Of course. The call for a capacity warranty was driven by two factors. The battery lease schemes, which are prevalent in Europe, set very clear limits for remaining usable capacity, which in turn guarantees certain range. The Volt sets another precedent, which I believe is driven by emission standards regulation, with minimum requirements for drivetrain warranty, and I'm familiar with the limits there too. I only mentioned this because you raised the problem of this new warranty threshold being too low. As already said, the implementation details are still being discussed, but Nissan has made it clear earlier, that five years warranty coverage is a target they were committed to in other markets, and the eight-year limited warranty is something they did specifically for the US, presumably to match GM on Volt coverage.
Right, you are correct in pointing out that any free warranty will be set up in a way, which will result in the lowest number of claims. Given the 70% threshold on the new capacity warranty Nissan just announced, there will likely be few consumers who would need it, even in Phoenix. That all makes sense so far. What I fail to see is the connection between more comprehensive warranty and more coverage as being somehow bad or detrimental. Most prospective buyers don't parse the numbers in such detail. All they hear today is "8 year warranty", and automatically assume that this covers capacity in the event that they lost significant amount of range, and cannot make their daily commute anymore.
Oh, I'm sorry, I must have overlooked that. We had this discussion in another context last year. The point raised was that automakers don't guarantee certain performance metrics, such as compression or the mpg rating, and the buying public should have the right expectations as to what might be warrantied because of that. The counter-argument was that the buying public also expects the vehicle to have the same range and the ability to go where it has gone before nearly in perpetuity. Yes, if you suffer a mechanical breakdown, and the car won't move or is not safe to drive, that would constitute a drive-train failure covered by warranty. This might happen in the event of a cell failure, and power output is already covered today. That's separate from the range issue however.
Anyone who knows anything about EVs, is familiar with the important role Tesla and the early EV adopters and advocates have played. That does not mean that you cannot try to deploy this technology on a larger scale now. From my experience in the LEAF community, I can attest that a number of folks would not be driving an EV today, if Nissan didn't make the LEAF. Yes, the LEAF is highly range-constrained, and one of the primary use cases is commutes to and from work. It's definitely not as capable as the Roadster or the Model S, but is it bad to have these cars out there? They will soon have sold 50,000 of them worldwide. Many LEAF owners have purchased a Volt or another LEAF as their second car, and replaced an older vehicle with combustion engine. Quite a few have ordered a Model S.
Yes, they hear "8 year warranty" as in the 8 year battery defect warranty all EVs have and assume it covers capacity (when it clearly doesn't if you look into the details).
