Supercapacitors Frequently Asked Questions


SUPERCAPACITORS also known as Electric Double Layer Capacitor or Ultra Capacitors is just like a Capacitor made up of two metal plates, but they’re usually coated with a sponge like, porous material known as activated carbon. The porous material makes the surface area a lot larger and boosts the energy density. They are immersed in an electrolyte made of positive and negative ions dissolved in a solvent. Finally, each of the Supercapacitor’s carbon electrodes ends up having two layers of charge coating on its surface, basically it is a double-layer capacitor with very high storage capacity. Typical Values range from few Farads to thousand Farads Capable of Charging within few seconds Light weight Very High Power Density (W/Kg).

SUPERCAPACITORS in it's present form bridges the gap between electrolytic capacitors and rechargeable batteries. Supercapacitors can accept and deliver charge much faster than batteries, and tolerate many more charge and discharge cycles than rechargeable batteries.

SUPERCAPACITOR consist of two electrodes separated by an ion-permeable membrane (separator), and an electrolyte ionically connecting both electrodes. When the electrodes are polarized by an applied voltage, ions in the electrolyte form electric double layers of opposite polarity to the electrode's polarity. The positively polarized electrodes will have a layer of negative ions at the electrode/electrolyte interface along with a charge-balancing layer of positive ions adsorbing onto the negative layer. The opposite is true for the negatively polarized electrode. Each of the Supercapacitor’s carbon electrodes ends up having two layers of charge coating on its surface, basically it is a double-layer capacitor with very high storage capacity.


Basically Supercapacitors are energy storage device like batteries, but they store energy in an electric field, instead of through a chemical reaction the way a battery does. The beauty of this Electrochemical component “Supercapacitor” is that it can be charged in seconds rather than hours and can be used for more than 1 million recharge cycles. Unlike batteries, it is environment friendly, maintenance free, efficiency level 98%, can operate at wide temperature range of -40 deg. C to + 70 deg. C , it covers life span of 15 years and does not show ageing effect. Supercapacitors typically have 10-20 times more Power Density than normal Batteries. Supercapacitors can store and can also discharge energy very quickly and can used in thousands of different applications. Supercapacitors can complement a primary energy source like an internal combustion engine, fuel cell or a battery which cannot repeatedly provide quick bursts of power. The future horizon looks immense for Supercapacitors as a green alternative energy resource.

Technology is developing with fast pace, but Power packs (Batteries) which powers these devices are not able to cope up with the power requirements. For example smart phones are struggling for power, Automobiles’ power demand increases by 100 Watts every year. Electric drive vehicles popularity is hampered due to limitation of Batteries. The dramatic rise of smartphones, tablets, laptops and thrust on Green Energy, Solar, Wind power, Recycling of Energy, Electric Mobility, etc has brought battery technology to the forefront of electronics research. Even as devices have improved by leaps and bounds, the slow pace of battery development has held back technological progress.

Green Energy, Mobility and Huge Data Centers are the key area to be focused for modelling sustainable Future cities.Energy may be of different variants/forms at point of Source, but in most cases point of use is in Electric form, either direct On-line or in stored mode. Electro-chemical Batteries are most popular device for Energy storage media. Environmental Hazards and human safety issues are commonly associated with use of Electro-chemical batteries, but these have been ignored on grounds of non-availability of alternative source in place of Batteries. Recent developments and Research break throughs have placed Supercapacitor in domain of Battery area.

SUPERCAPACITOR is like the wonder child of a capacitor and a battery. It can hold a charge and dispense electricity over a long period of time like a battery, and can also take in and store energy to be released in sudden bursts like a capacitor. This makes it an excellent power source for applications where Batteries are not able to deliver, like in cold weather, Regenerative Braking, Power burst, etc. Supercapacitors are also best suited for Solar, Wind mill by improving its Run time, Supercapacitors are also capable of improving equipment uptime and power reliability. A Supercapacitor-based engine start module enables any vehicle light-duty or heavy-duty industrial vehicles and buses with diesel or petrol engines to start and operate reliably in temperatures down to -40°C. Able to start an engine when batteries can’t, Supercapacitors can completely take over the engine cranking and starting function by remaining fully charged, even if the battery voltage drops significantly. Supercapacitors in present stage of development can boost electric mobility applications ranging from 2-wheelers, 3-wheelers, cars, buses, trains, metro, trams, etc.

Beyond Automobiles and Electric vehicles, Supercapacitors could play an interesting role in powering electronic gadgets and cell phones to squeeze out extra energy and help a cell phone last longer, and charge in seconds and also for power grid during a peak demand., and host of many other applications. Supercapacitors can complement a primary energy source like an internal combustion engine, fuel cell or battery, which cannot repeatedly provide quick bursts of power. Supercapacitor is considered in a host of future energy related applications. The future horizon looks immense for Supercapacitors as a green, alternative energy resource.

If a supercapacitor is exposed to excessive voltage or temperature for extended periods of time it will gradually degrade to essentially an open circuit condition. The time taken for this to occur depends on how much over-voltage or over-temperature is applied. Other than physically puncturing the supercapacitor, there are no short circuit failure modes. There are no catastrophic failure modes.

Even though Supercapacitors (Symmetrical EDLC) have polarity, inherently they are a non-polarized device. However, once they have been charged the ions in the electrolyte migrate to the positive and negative electrodes. Reversing polarity causes these ions to migrate across the device and will result in an increase in ESR. There are no safety issues if a supercapacitor is reverse biased, there will be no explosion, fire, smoke, or swelling. All of our supercapacitors go though extensive testing and burn-in at voltage and as part of this process they are polarized in the manner indicated on the part.

: Please Note Polarity of "Assymterical Supercapacitor / Psuedo-Supercapacitors" cannot be reversed. If done it will damange the cell

SPEL offers wide selection range of Supercapacitors ranging from single cells to modules of voltage upto 700VDC for various applications. In order to size the appropriate Supercapacitor capacity for any application, we need to be clear on following parameters
  • Maximum Charged Voltage (Vmax), if different from Working Voltage then also (Vw)
  • Minimum permisble load Voltage (Vmin)
  • Required Current (I)
  • Desired Backup time (t)
  • Duty Cycle
  • Average Operating Temperature
  • The last two parameters are used to determine the life degradation factor which is not discussed here but it's consideration is desired. Below provided calculator is an attempt and guide to assist user to determine exact capacity/value of Supercapacitor for his desired application.

    Enter Rated working Voltage (VDCmax):  
    Enter Required Current (AMPERE):  
    Enter Minimum Voltage (VDCmin):  
    Enter Required Back-up time (SECONDS):  

    Required Supercapacitor in FARADS

    Resultant Impedance in OHMS

    Assymetrical Supercapacitor also reffered to as Pseudocapacitor, is a hybrid between a battery and an electric double layer capacitor. Unlike EDLC Supercapacitor which haves symetrical electrodes, assymetrical supercapacitor consist of seperate predefined anode, and cathode. Charge storage occurs by chemical and electrostatic means.

    The pseudocapacitor combines best of both the worlds of BATTERY and SUPERCAPACITOR. quick release of energy via an electrostatic mechanism (like an ultracapacitor) and higher storage capacity via an electrochemical mechanism (like a battery).

    SPEL pseudocapacitor have approximately 2 to 3 times more energy density as compared to convectional Supercapacitors of similar physical dimensions.


    Enviornment Friendly

    Unlike Batteries, it is clean storage system with zero Enviormental threat..

    Highest Power density

    Supercapacitors have a low ESR reulting in more efficiency & less heating.

    Amost infinite Charge Discharge cycle

    Typically from 65 degrees Celsius to

    Wide Temperature Range

    Wide Temperature range. Typical -40 degC to +70 degC

    Quick Charging

    Fast Charging.

    No ageing effect

    No aging effect

    High on efficiency

    Almost 99% efficiency

    No Thermal Runaway

    Unlike Lithium Ion Batteries, No thermal Runaway



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    SPEL is a customer-focused, Research-oriented manufacturer of Power-Saving, Power-Delivery, Power-Conditioning and Advance Power-Storage products for the global market. SPEL is committed towards continuous innovation and improvements through research and product development for utmost customer satisfaction without compromising on "Environment" obligations and performance value of product at competitive cost.


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