Expert: What You Know About Lithium Batteries Is Wrong, Can Last Up To 20 Years

4 years ago by Jay Cole 11

A Good Thermal Active Management System, Like The One Found In The Chevrolet Volt, Should Extend Useful Life Past 8 Years Of Service

A Good Thermal Active Management System, Like The One Found In The Chevrolet Volt, Should Extend Useful Life Past 8 Years Of Service

Most end of life calculations for electric vehicles are based on an assumption of achieving 8 years of useful operation before falling below 80% of original capacity.  However, a battery expert has told the American Chemical Society in a speech last week that we can reasonably expect a much longer life.

How much longer?

French Battery Expert Expects Longer Than Expected Results From Today's Lithium-Ion Battery Technology (Focus Electric Shown)

French Battery Expert Expects Longer Than Expected Results From Today’s Lithium-Ion Battery Technology (Focus Electric Shown)

How does 15 or even 20 years sound?

That kind of longevity would certainly tip the cost of ownership scales in the favor of plug-in cars over their contemporary gas siblings.

And that extended longevity expectation is just what Mikael Cugnet, of the French Atomic Energy Commission, has said could be a reality.

He noted that current benchmarks are a product of accelerated tests that may not be providing an accurate preview of how long the batteries could actually last. Over time, Mr. Cugnet believes that if the battery packs inside EVs are maintained properly, plug-in vehicles could “reliably” last 15, maybe 20 years.

In a interview with Design News, Cugnet said:

”The accelerated testing that’s performed in labs is not exactly representative of what will happen during real road use.  Accelerated testing is usually performed at much higher temperatures and in a much shorter time period than you’d see in real-life use. That’s why people are getting such low values.”

Last Year In Asizona We Learned First Hand What Happens To Lithium Batteries Operating Well Outside The Norms (picture via MyNissanLeaf)

Last Year In Arizona We Learned First Hand What Happens To Lithium Batteries Operating Well Outside The Norms (picture via MyNissanLeaf)

The expert says that these accelerated battery tests take place at temperatures as high as 104F, and that is a much greater average temperature than can be expected in the real world, at least in the majority of situations.

“That’s the way we do it because there’s not enough time to do a real field test,” he said to Design News, “But it’s not accurate. It doesn’t represent what the battery will really see in the field. 

Up to now, researchers have also based their estimates for lithium batteries on prior experience with lead-acid and nickel-metal hydride…Lithium-ion batteries should perform better because they have fewer impurities, so the degradation will not be as fast.”

Factors that affect battery life according to Mr. Cugnet are:

  • temperature – the higher the average temperature a battery is subjected to, will translate into less life.   The expert explains, “If you’re living in Abu Dhabi, the battery life will be much shorter than if you’re in a place that has colder winters, and if you have your car parked under the sun in Atlanta or Louisiana three months of every year, the battery won’t last 20 years.”
  • charging techniques – too many “fast charges” can damage the ability of a lithium battery to hold a charge over time
  • state of charge – although wildly impractical for obvious reasons, lithium packs that are only charged to 50% will last the longest.  Ideally, a charge should stay between 20% and 80% of total pack capacity
  • management system – an on board active cooling system, whether that be air or liquid, is a big assist to battery life.

The researcher from the French Atomic Energy Commission concludes that by optimizing the above factors, electric vehicle owners should achieve a lot more than eight years of use before losing more than 20% of the battery’s original capacity.

Design News

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11 responses to "Expert: What You Know About Lithium Batteries Is Wrong, Can Last Up To 20 Years"

  1. Driverguy01 says:

    looks like im gonna love my Volt a long long time….

  2. SuperDave says:

    Same here with my 2013 Ford Focus Electric!

  3. Robster says:

    Hi Jay, please check your spelling once more. Bit too fast maybe:-)
    Anyway, good news, I hope he’s right!

    1. Jay Cole says:

      Sorry Robster my bad,

      Article was put out/composed entirely from Epcot in Florida with the family from the Norway pavilion, heeh…focus might have been a touch low, (=

      “…those who come to Norway face both peril and adventure” – Maelstorm

      1. Robster1979 says:

        You’re bloody well right then:-)

  4. Mark H says:

    Mr. Cole has secretly argued this for quite some time. So glad the American Chemical Society has backed it up. For the spelling, great technical minds always struggle with the laborious task of editing.
    Really GREAT article Jay!

  5. Brian says:

    Heck, maybe my Leaf will last me 20 years even without TMS. I also wonder what will happen after “EOL” 80% – will the capacity drop like a stone, or continue a gradual decline? For those of us who only need maybe 30% of the range on a regular basis, will the battery last for 21 years? Or 50 years?

  6. James says:

    It’s great news to here this information from battery chemisty experts!

    GM went the right way in placing such large buffers on their pack, and
    it explains how they can open that up a bit for 2013-and-beyond Volts
    and ELRs. Coddling the pack is expensive but well worth it in the end.

    It also makes me wonder if GM could use more of the pack after a few
    years with a software update – to lengthen the lifespan of the pack and
    make replacement unnecessary for 12-15 years!

    All in, makes purchasing, rather than leasing a Volt or Ford Energi or
    FocusEV a bit less of a risk.

  7. Battery Wary says:

    What about charge efficiency as capacity drops? Has any research been published on this topic? We have all experienced that Li laptop or phone battery that draws power for just as long as a new/healthy battery without the capacity to show for it.

    1. Mark H says:

      For those of us who love data it is a great question. But to make a quick comparison, the American Chemical Society is stating that a well managed battery could last 20 years.

      What kind of compression can you maintain on a 20 year old ICE? You either spend a lot of money on a major rebuild or you have a lot less mpg than you did in the first 100,000 miles.

      It looks like the EV is going to perform a lot better but even if it does not, you are looking at the equivalent of paying $1.20 per gallon equivalent opposed to $1.0. To make the same comparison, the ICE that used to get 27mpg is not getting anywhere near that after 15 years.

  8. Ocean Railroader says:

    I had a lithium battery powered Cell Phone that lasted over seven years on the same battery.

    To me the main thing that has killed a Ice Car engine for me that made get rid of it is when it starts having transmission problems or if the car has a flaw in it’s building that makes it’s prone to things going wrong with it. A Electric car might fair better if it has less moving parts in it and if you have a battery that came with the car with a 75 mile range but a few years down the line they start coming out with 200 mile range batteries for the same car. While with a Ice car the transmission goes and you can’t find a new one so you have to get rid of it.

    I sense there could be a huge market for electric car battery upgrades two to five years in the future.