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How to Kill an Ultracapacitor, if You Really Want To

When working within their specified operating parameters, ultracapacitors will provide a stubbornly long and trouble-free existence. Ultracapacitors will outlast most other electronic components in any given application, which is why they are the perfect power delivery device in the most demanding environments.

However, an ultracapacitor can meet an early demise if you really want it to — though the list of things you can do to kill it is pretty limited. Paying attention to the following circumstances will ensure the maximum lifetime of your system’s ultracapacitors.

Operating temperature: An ultracapacitor doesn’t rely on electrochemical reactions to generate or deliver power or energy. It operates (simplistically speaking) electrostatically. So it stands to reason that electrochemical reactions in an ultracapacitor are not only absent by design, but also unwanted. Increasing temperature catalyzes chemical reaction rates. This generally applies to ultracapacitors, as they are chemical systems. Therefore, if you want to kill an ultracapacitor, operate it outside of its specified operating temperature, and you will be sure to degrade its capacitance excessively, increase its resistance at unacceptable rates, and decrease its efficiency dramatically. The magnitude of the effects is proportionate to the temperature beyond specification and the time spent at that temperature.

Operating voltage: Electrochemical systems generally exhibit a stable operating voltage range beyond which the system becomes unstable, electrochemically speaking. Similar to over-temperature, the effects of overvoltage include increasing decay rate in capacitance and increasing rate of resistance rise. Overvoltage will also increase the gas generation rate inside the cell. If the overvoltage is severe enough, the gas will increase to a level that will result in over-pressuring the cell from the inside out and venting, followed by cessation of function. Ultracapacitors, unlike some other electrochemical storage technologies, do not have an under-voltage limit. In fact, reverse voltage, while not desirable, will generally not kill an ultracapacitor or create a dangerous situation, as long as the reverse voltage is not over the absolute value of the voltage specification when normally operated. As with temperature, the impacts of overvoltage are dependent on the overvoltage magnitude and the time spent at that condition.

High voltage and high temperature: The worst of all worlds is an overvoltage condition coupled with an over-temperature condition. In this case, electrochemical reactions and gas generation are both accelerated, resulting in high rates of capacitance and resistance decay, rapid gas pressure buildup in the cell, and irreversible degradation of the active materials in the cell, including the electrode active materials matrix and the electrolyte. Exposing the cell to this lethal combination is the easiest way to kill an ultracapacitor.

Mechanical abuse: Exceeding mechanical specifications for ultracapacitors, such as vibration specifications or shock events, will kill all but the heartiest of devices. Sometimes death will be instantaneous. Maxwell ultracapacitors have a distinct advantage over competitors in this area due to a robust and unique dry electrode and specially engineered cell construction. However, all manufacturers have their limits, and exceeding any manufacturer’s specifications can result in the rapid demise of the device.

Ultracapacitors are not susceptible to dying young unless they are exposed to out-of-specifications conditions. It is important to understand why manufacturers specify their devices as they do and what evidence and data is available to substantiate that the particular device is up to the task. Specifications are defined by the manufacturer and, as such, are sometimes subject to interpretation. My advice is to ask questions, demand data, and operate the device inside the specifications. This way you won’t be disappointed by your decision to use ultracapacitors in your most demanding applications.

65 comments on “How to Kill an Ultracapacitor, if You Really Want To

  1. geek
    August 22, 2014

    @Mike: Interesting post. Is there are a life span for ultracpacitors? I mean is there a time period after which they should be replaced even if there's no malfunction?

  2. MAEverett
    August 23, 2014

    I have never seen an Ultracapacitor die of natural causes. In other words operated inside specification they don't have a failure mode where the just quit working. The natural decay in capacitance and rise in resistance is the service life determiner. When the device no longer has sufficient energy (runtime) or power to meet the need of the application the it's time to replace them. Otherwise use them inside spec until they are incapable of supplying the needed power or energy. They really will outlast the application they are in if they are sized correctly for it and the operating conditions are well understood. Often however this is not the case however. Many applications are new and not fully characterized over lifetime so there is many times some learning involved in how to make them last throughout.

  3. samicksha
    August 23, 2014

    I am taking an examle of Laptop which we use on daily basis and fluctuating supply can damage the device but yes ultracapacitor can help here to stabilize the supply.

  4. samicksha
    August 23, 2014

    These high end capacitor keep promise to last for long, can we see them replacing our cell phone batteries some day ??

  5. Netcrawl
    August 24, 2014

    @samicksha I like that idea, using ultracapacitor in laptop that would beb great. they're much safer than Lithium Ion batteries, Lithium Ion batteries have circuitry inside to prevent overcharging and even shorts. But if the circuitry damaged or fail, then the battery could be overheated, this could result to what we called “thermal runaway”, a chemical process where the battery generates more heat causing additional reaction like explosion or erupting battery. 

     

  6. Netcrawl
    August 24, 2014

    @samicksha I believe its possible but it going to take some time, adoption is key, lithium ion is still the top choice for most manufacturers.

  7. Netcrawl
    August 24, 2014

    @tzubair ultracapcitors have a much longer lifespan, they can also charged and recharged indefinitely. The best things about ultracapacitors is that they can act as a power supply to your gadget, not only charge your device faster but also gives those devices a charge that could lasts for a longer period of time. In addition, they dont waste much energy, making them much more efficient than traditional batteries.

  8. samicksha
    August 24, 2014

    I agree to your point @Netcrawl, batteries can explode violently and specially when we talk lithium ion batteries. But yes i also admit the truth as well replacing these batteries with such capacitor can eat lot of time.

  9. MAEverett
    August 24, 2014

    Thanks for all the good discussion folks. Everything you all have said is largely true with one caveat. Today's Ultracapacitors are relatively low energy density compared to batteries. Therefore while its true they charge very fast for many many cycles and deliver their energy very quickly the Ultracapacitors don't have the energy to run a cell phone for very long. The Ultracapacitors are good for power delivery in the timeframe of seconds to minutes. Over that and batteries are still required. Look at my older blog about batteries and capacitors together. You will see that these two technologies work well together but only In short term burst power applications can Ultracapacitors replace batteries. Someday maybe but for now the Ultracapacitors just don't hold enough energy per unit volume. Thanks for reading. Mike

  10. vasanjk
    August 24, 2014

    MAEverett,

     

    It is important to discuss the merits of each (Ultracaps and Batteries) with respect to their specific application focus. Each has specific utility though there are overlaps. Replacing one with another without care may have an impact on performance and/or cost.

  11. dassa.an
    August 25, 2014

    @samicksha: Well they explode if they are not been maintained properly. Power maintenance is a key factor here 

  12. samicksha
    August 25, 2014

    I agree you @dassa.an, i guess its all about power management but in today's busy schedule we can hardly concentrate on charging battery to full, infact a person like me tend to use phone even if it is half charged.

  13. eafpres
    August 25, 2014

    @Mike–thanks for the informative post.  I think that ultra-caps in combination with batteries as a system have merits in many cases.  So I suggest to our readers instead of thinking Ultra-caps OR Batteries, consider Ultra-caps AND Batteries.

  14. eafpres
    August 25, 2014

    Hi Mike–another thought you might shed some wisdom on.  Over at ALL LED Lighting we talk about LED power supplies (aka drivers) all the time.  Invariably the discussion includes the fact that the electrolytic caps are one of the highest failure modes.  Are you seeing interest in small ultra-caps as a more reliable solution in solid-state lighting power designs?

  15. eafpres
    August 25, 2014

    Hi Mike–last question.  Can you comment on the behavior of ultra-capcitors in very cold environments?  Such cases are challenges even for batteries at times.

  16. MAEverett
    August 26, 2014

    Hi EAFPres1 and all others, I will respond to all three of the last posts in one post of my own. The combination of UCAPs and batteries are a match made in heaven so to speak. Each has its strengths as one of our colleagues noted in an earlier post and you are correct, they are complimentary. An energy optimized battery coupled with UCAps is the optimum technical solution for life of the application service in applications that have a power and an energy component. And you will have to think a bit to come up with ones in the transporation industry that dont have both. Regarding solid state lighting, we did have some interface a while back (some years ago now)  with the leaders (at the time)  in the LED space but did not result in a design-in. There is not much pull from the industry for replacement of electrolytics probably because the power of the UCAP is still below that of the electrolytics and the UCAPs are more expensive. You get more energy from a UCAP than an electrolytic but in the application there is likely no need for that energy. So we are not feeling the pull from the industry you inquired about. Finally at low temperture nothing beats an ultracapcitor. They are fully functional down to -40C with less than a doubling of the resistance of the device. Long before that batteries have given up and have no power at all. So one of the major benefits of the ultracapacitors by Maxwell is their extraordinary low temperature performance. And as the blog started, the lower the temperature the better for lifetime of the devices, so they love it cold. Thanks again for the good questions and discussions. Talk with you later, Mike

     

  17. PCR
    August 26, 2014

    Mike Many thanks for the insightful article

    True dassa.an I do agree with you that power maintenance is a key hear. 

  18. PCR
    August 26, 2014

    Samicksha, I believe that we have stabilized supply but the real problem is life of the battery isn't it? 

  19. PCR
    August 26, 2014

    Netcrawl  it is a good news, if it can answer the problem of having a long battery life in mobile devices it will be in the top in the list with no time for sure. 

  20. PCR
    August 26, 2014

    Netcrawl , what will be the cost factor of these ultra capacitors compared with  traditional batteries

  21. samicksha
    August 26, 2014

    I guess a normal phone provides 06 of talk-time if fully charged but problem is application and e-mails configured in phone which consumes hell lot of power..

  22. chirshadblog
    August 27, 2014

    @Ranasinghe: Well cost would definitely be high but I feel its still worth. 

  23. chirshadblog
    August 27, 2014

    @Ranasinghe: Yes indeed because that is what is required right now. Cost will be highlighted a bit but with stability it will get blocked. 

  24. chirshadblog
    August 27, 2014

    @Ranasinghe: Battery life can be improved but it will cost a bit. Only question is whether the market will accept it or not

  25. chirshadblog
    August 27, 2014

    Ranasinghe: Yes by doing that only you can ensure that its in good shape. If not we will not realize it until its been utilized  

  26. Netcrawl
    August 27, 2014

    @chris you're right adoption is key, and the there's the enonomic issue- the cost of producing these products.

    The two technologies- battery and ultracapacitors, remind us of the famous fable “the turtle and the hare”. In which the battery represents the turtle as a slow ( which also right) and steady energy supplier for most of today's energy demands, while the ultracapacitor represents the hare that have these unique capabilities, able to charge and discharge for low energy demands.

    I think its wrong to view them as competing technologies, its may be useful and great to view them as complementing technologies ( I do believe thats the right things to do now). By combining the two technologies we could unlock something new, combining their strengths to reach a common goal: a battery-ultracapacitor hybrid.

     

  27. Netcrawl
    August 27, 2014

    @Chris Ulatracapcitors have many uses and advantages but it still can't compete with batteries when it comes to storing lot of energy, today's commercially-built ultracapacitors could store around 25 times less energy than a similarly sized Lithium-ion batteries, as a result they need to be much larger than the batteries to hold the same energy charge.     

  28. Netcrawl
    August 27, 2014

    @samicksha would you believe if I tell you that I'm still using the Nokia's old models- 1100 and etc. in some work especially during travel. They're highly reliable and provides a much longer talk time, they can lasts longer. The new models- the touch screens, they're consumes lot of power, email and apps those things are eating my power supply. They can only go for about 2-4 hours.  

  29. Netcrawl
    August 27, 2014

    @Ranasinghe its true it could be the answer to today's battery problem, the best things about ultracapacitor is it's storage mechanism. It safe because it does not involve any chemical reaction, energy is stored electrostatically. And they can charged quickly and can lasts for millions of charges/discharges without losing energy storage capability.

    The problem with ultracapacitor is the cost, the cost of ultracapactor materials often exceeds the cost of battery materials due to the increased difficulty and complexity in creating high-performing ultracapacitor materials.      

  30. samicksha
    August 27, 2014

    Exactly my point @ Netcrawl, applications on smartphone consume lot of battery but with same i even realize that smartphones are becoming need with increasing demand of BYOD adopted at different levels in almost all the companies.

  31. dassa.an
    August 27, 2014

    @samicksha: Well in any smart phone the battery life is an issue when it comes for apps. But smart phones are built for apps so without apps there are no smart phones. 

  32. Victor Lorenzo
    August 28, 2014

    The number of installed applications could some how influence the overall system's power consumption as the larger the files count in the file system the larger the number of flash read operations required for locating any specific file in the flash file system, but this influence could be neglected in most cases.

    The number of running applications and the number of context switch operations produced by the running processes does negatively impact the power consumption as idle (low power) time reduces. The underlaying operating system is also responsible for power consumption.

    The other source of power consumption is the number of open data connections. The longer the RF interface and the baseband processor can stand in low power mode the longer the battery will last. This is one major reason why the old phones (non smart ones) can provide a much longer batery life time.

    Of course, the CPU technology will also have a big impact on power consumption. A dual core 1.0GHz processor with a quad core graphics processor/accelerator will consume much more power than a single core processor that generates no graphics at all for a classic LCD screen. TFT screens consume more power than AMOLED and much more than monochrome LCD screens.

    Having a powerful, smart and fancy phone full of gadgets has that inconvenient.

  33. Victor Lorenzo
    August 28, 2014

    @dassa.an, that's generaly true but we can find very large differences between several manufacturers and models.

    I have two smartphones in use, both are mid-to-low end devices, one from Samsung (ACE) and one from Huawey (Vodaphone smart). I must recharge the ACE every two/three days. The V.Smart used to last 1.5 week. I use the V.Smart at this time only for its camera and as a music player and I only need to recharge it once a month. But it has no SIM so the RF and baseband processors are disabled.

    Some colleagues are using models from Oppo, Samsung, HTC and Nokia, they must charge the phone every day and in some cases more than once a day (continupusly connected to the dock station).

  34. Victor Lorenzo
    August 28, 2014

    @Mike, I'm working on a project where I need to harvest energy from a fast current pulse signal. The whole pulse lasts for less than 100us, is not repetitive and, of course, I need to harvest the highest possible amount of energy from any single pulse. Do you think these capacitors could serve for this purpose? Is there any app note covering this application?

    For solar cell powered applications, how does this capacitors compare in price to other energy storage technologies?

    Thanks a lot, Victor

  35. samicksha
    August 28, 2014

    I was reading breif on research report by standford university wherein they have devoloped new battery design and technology which seems to be a pure lithium anode that could boost power capacity and extend battery life.

  36. dassa.an
    August 29, 2014

    @samickshaWell that seems good news for the battery itself but what about the consumption? I guess it's a bit higher than the usual. Any idea ? 

  37. chirshadblog
    August 29, 2014

    @Dassa.an: According to my knowledge power consumption is not bad. 

  38. samicksha
    August 29, 2014

    Yes it is , but i only have very limited information on this subject. I guess this product or project is still at very initial stage.

  39. geek
    August 30, 2014

    @Netcrawl: I understand that ulltracapacitors have a considerably longer life but they surely can't last forever. Like all other circuit components, they also must be having a life span after which they'd need to be replaced. That should be indepenedent of the application.

  40. PCR
    August 31, 2014

    chirshadblog these days cost factor come within the top five, so this will be a great situation for the extreme situations.  

  41. PCR
    August 31, 2014

    chirshadblog then it will be a big issue when marketing, I feels it will be rejected initially. 

  42. PCR
    August 31, 2014

    If it is true Netcrawll, this won't be a option for phone batteries. Cause that day by day designers will go for smaller batteries in order to give more spaces for other option. 

  43. PCR
    August 31, 2014

    Victor, that is because most of the smart phone users are addicted to the device. Sometimes it is worth giving a call than chatting over the time. 

  44. yalanand
    August 31, 2014

    @Mike, thanks for the post. Some really useful tips regarding how to protect an Ultracapacitor. I am curious to know for how long Ultracapacitors lasts and till what max temperature Ultracapacitors work normally?

  45. yalanand
    August 31, 2014

    ultracapcitors have a much longer lifespan, they can also charged and recharged indefinitely. 

    @Netcrawl, does that mean they can supply charge for indefinite amount of time or are you trying to say that even if we overcharge them they dont get damaged ?

  46. yalanand
    August 31, 2014

    These high end capacitor keep promise to last for long, can we see them replacing our cell phone batteries some day ??

    @samicksha, I dont see any reason why we cant use such capacitors in cell phone batteries. We can charge such batteries pretty faster compared to conventional batteries and hence it will help the end users to charge such batteries quickly.

  47. yalanand
    August 31, 2014

    lithium ion is still the top choice for most manufacturers

    @Netcrawl, true but there are many disadvantage of Lithium Ion batteries also like it requires protection circuit and its subject to aging, even if not in use.

  48. yalanand
    August 31, 2014

     i guess its all about power management but in today's busy schedule we can hardly concentrate on charging battery to full, infact a person like me tend to use phone even if it is half charged.

    @Samicksha, I totally agree with you. I can never charge my battery to full because I am heavily dependent on my  mobile and cant stop using it for even an hour. We need better batteries to charge them quicker.

  49. yalanand
    August 31, 2014

    Someday maybe but for now the Ultracapacitors just don't hold enough energy per unit volume. 

    @Mike, recently read an articles which suggests that in future Ultracapacitors can be converted to Batteries. Here is the link : 

    web.mit.edu/erc/spotlights/ultracapacitor.html

  50. yalanand
    August 31, 2014

    what will be the cost factor of these ultra capacitors compared with traditional batteries

    @Ranasinghe, apart from cost factor other things also play crucial role when we compare ultra cpactiors with traditional batteries. For example in electric vehicles charge time is important cost factor.

  51. yalanand
    August 31, 2014

    applications on smartphone consume lot of battery but with same i even realize that smartphones are becoming need with increasing demand of BYOD adopted at different levels in almost all the companies.

    @samicksha, no doubt smartphone consumes lot of energy but sometimes the apps which run on smartphones are not optimal and they consume lot of energy. So all the app developers should make sure that they follow the guidelines to make sure that apps dont consume so much of energy.

  52. Netcrawl
    August 31, 2014

    Ultracapacitors are different and its considered as the best device in delivering a quick power of surge. Because they store energy in electric field rather than in a chemical reaction, this is a very important distinction because storing energy without chemical reaction allows ultracapacitors to discharge and charge much faster than battery. This  also makes them highly reliable, it can survive hundreds of thousands of discharge and charge than a battery can. They dont get damage even we overcharge them, they dont suffer the wear and tear of the chemical reaction.

    Hang around the energy storage crowd, you will hear some chat and talks  about ultracapacitors, its great and still the top choice for mots applications like electric cars and power grid. 

  53. Netcrawl
    August 31, 2014

    @yalanand thanks for the link, ultracapacitors are like a small bucket with big spout, it can flow in and out very quick but there's not very much of it while battery is like a big bucket with tiny spout where it can hold much water but takes a long time (which is really true) to fill and drain them.

    Ultracapacitors are very promising and effective, they are good in accepting a sudden surge of energy, I think this make them a top choice in electric cars because it can provide the power needed for acceleration.    

  54. Netcrawl
    August 31, 2014

    @Yalanand ultracapacitors can be make a good partners for lithium-ion batteries because they're good in accepting or delivering a sudden burst of energy. For me the they could makes a good partner, why? in electric cars for example ultracapacitors can provide the sudden burst of power needed for acceleration while the battery (Lithium-ion) provides a range and recharges the ulracapacitors between surge. 

  55. yalanand
    August 31, 2014

    Ultracapacitors are very promising and effective, they are good in accepting a sudden surge of energy, I think this make them a top choice in electric cars because it can provide the power needed for acceleration.    

    @Netcrawl, I agree with you. I think they are also widely used in military related applications like backup power modules, GPS guides etc.

  56. yalanand
    August 31, 2014

    ultracapacitors are like a small bucket with big spout, it can flow in and out very quick but there's not very much of it while battery is like a big bucket with tiny spout where it can hold much water but takes a long ti

    @Netcrawl, thanks for sharing the analgoy example. It really helps us toknow the exact difference between Ultracapacitors and batteries.

  57. SunitaT
    August 31, 2014

    I totally agree with you @ samicksha. It is barely unworkable to wait for the battery to be left till fully charfed prior to usage with the busy schedule in place. Even if that were to happen, you will get to realize that it is only possible overnight which will again result to overcharging, pending explosion.Tricky situation whichever way!!!

  58. SunitaT
    August 31, 2014

    Thanks Mike for this informative piece of writing. However, just as eafpres1,can you please shed more light on what to expect with batteries on relatively cold environments as it turn out to be a challenge most of the times.

  59. SunitaT
    August 31, 2014

    @ Mike, Are  there be other possible ways in which one can unknowingly shorten the life of his device's battery? 

  60. SunitaT
    August 31, 2014

    To be frank, you nailed it@ eafpres1. A combination of both the ultra-caps and battery as a system would be the best option worth going for as this will turn out to have more benefits. It's more or less a matter of playing safe and being on the safer side always.

  61. SunitaT
    August 31, 2014

    I totally agree with Netcrawl. It would require sime time for the replcaement of lithum iron. For now that's the best the companies can offer.

  62. MAEverett
    September 2, 2014

    Hello Yalanand

     

    Not sure what you mean by how long will they last, but i will assume you mean lifetime not runtime since we had that discussion already. Lifetime of the UCAP is far longer than the lifetime of a cell phone, so it will outlast the device for sure. In fact the UCAP will outlast most applications and are designed generally to last lifetimes of automobiles, 10 years. But the topic of the blog is how to shorten that life, so operated it inside spec and you can get seriously long lifetimes. Most other things will fail before the UCAP does. The upper spec limit of temperature is generally 65C, but that does not mean you can operate it there for its entire lifetime. it will degrade faster there than at room temperature or around there. If you need to know the lifetime of the device in a particular application, Maxwell applications engineering can help with simulation modeling of performance over life, assuming the operating conditions are known, this is not always the case, but the modeling is pretty solid so if known, prediction can be made about how long the devices will last.

    Mike

  63. samicksha
    September 11, 2014

    I agree to your point but a study by wired.com says that the iPhone battery has improved by 15% since the first iPhone hit the market, but it is obvious that the capability of the hardware and demands of software have grown .

  64. yalanand
    November 27, 2014

    wired.com says that the iPhone battery has improved by 15% since the first iPhone hit the market, but it is obvious that the capability of the hardware and demands of software have grown .

    @samicsha, I think this trend will contibue. Demand for bigger capacity battery will grow because new mobiles have new features added which increases the power consumption.

  65. yalanand
    November 27, 2014

    Not sure what you mean by how long will they last, but i will assume you mean lifetime not runtime since we had that discussion already.

    @MAEverett, Mike yes I was referring to lifetime. Thanks for the clarification.

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