Ultracapacitor Applications and FAQ

What is an ULTRACAPACITOR?

LiCAP Ultracapacitor

Ultracapacitors and super capacitors are high power capacitors that store much more energy than a traditional capacitor and have incredible power attributes.  The scientific term for the technology is Electric Double Layer Capacitor (EDLC).  Instead of a chemical reaction like a battery to produce energy, the EDLC is a physical process shuttling ions from one side of the electrode to the other.  The physical process is very efficient and allows for a storage cell with 1000 times the life of the best lithium ion battery in cycles and 20 times the power output of the best lithium ion battery.  Because EDLCs or ultracapacitors do not rely on a chemical process to make energy, they have a wider operating temperature range spanning from -40℃ to 65℃.  The limiting factors of the ultracapacitor is low voltage and limited energy storage.

Where Ultracapacitors Shine

Ultracaps have many applications in rail as motive power.

Ultracapacitors work best where they can use their immense power.  Here are some good examples:

  1. THE TUGBOAT CONUNDRUM.  Tugboats have huge engines for their size as they have to push heavy loads such as large ships or barges.  Once the load is moving, the tugboat engine uses comparatively little effort for more than 90% of its operational time.  It is imperative that the tugboat has the power to move huge loads but that power is expensive to feed for more than 90% of its operational time.  What if there was a way to have the power AND be more efficient?  Ultracapacitors are the answer.  If the tugboat were electric, a string of ultracapacitors in parallel to the batteries would supply the brute power to move ships and the batteries or generator would supply the constant energy to keep the tugboat moving from point A to point B.  
  2. PRESERVING BATTERIES and extending the operating time of battery operated vehicles and equipment is what ultracapacitors are uniquely suited.  Ultracapacitors in parallel with battery strings will take on the high power spikes and preserve the battery from heavy loads allowing the battery to work just at its perfect rated output.  High power requirements such as starting and accelerating cause the battery to work hard and create heat which reduces run time and battery life.  Ultracapaitors have been proven to double the battery life regardless of the chemical makeup of the battery and extend the run time as much as 25%.  
  3. ENGINE STARTING POWER comes from the ultracapacitor's high power.  Twenty times the power of a lithium ion battery and nearly 150 times the power of a lead acid battery allows ultracapacitor batteries to start small and large engines with ease.  This is a popular application of late as ultracapacitors work well at extreme temperatures from -40℃ to 65℃.  Ultracapacitors can also improve engine performance by giving components such as electronic fuel injectors and ignition coils unrestricted flow of current.  In addition, the alternator charges the capacitors immediately therefore limiting the alternator drag on the engine.  
  4. POWER CONDITIONING is a byproduct of the ultra capacitor's ability to take abuse and heavy loads over 1 million times during its life.  In Wind Energy and Solar power systems, the energy generated is in DC and intermittent.  Ultracapacitors can work between the energy source and the power grid to condition the power before it is put into the grid.
  5. MICRO GRID SUPPORT is a perfect application for ultracapacitors as local power networks spring up to support new energy plans.  Ultracapacitors can mitigate the expense of delivering additional power to a building or complex where peak usage has caused excessive voltage drops.  Voltage drops can cause breakers to trip and unplanned system shutdowns.  Installing banks of ultracapacitors will provide necessary power during peak moments ameliorating the need for expensive additional power to be brought in by the utility.
  6. EXTREME POWER is needed for wind turbine pitch control.  Over 80,000 wind turbines worldwide use ultracapacitors to operate the pitch control for each turbine blade.  Pitch control is essential to optimize power generation and to keep the wind turbine safe during high winds or storms.
  7. CRITICAL POWER applications have a major weak link and that is the battery that backs up the system or provides a short time bridge to generator power.  Battery failure is still the number one cause of critical power system unscheduled downtime.  Ultracapacitors can be used exclusively as a bridging power conditioner in a UPS system that will last the lifetime of the UPS and give 100% uptime due to its ability to work in a wider temperature range and be cycled 1 million times.  In systems where there is no generator and the batteries provide the backup power, the ultracapacitors can be used in parallel to double the life of the batteries and extend the run time.

Frequently Asked Questions (FAQ)

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Question:   Can I get an ultracapacitor in higher voltages than 2.7V?  


Answer:  Electric Double Layer Capacitors (EDLC), ultra capacitors, or super capacitors are limited in voltage by physics to a theoretical voltage of 3.3V.  Common voltages are 2.7 to 3.0V.


Question:   How do you compare ultracapacitors with the same Farad (F) rating?


Answer:   The two main specifications after physical size of the ultracapacitor are Capacitance which is represented as Farads (F) and Equivalent Series Resistance (ESR) represented as milliohms (mΩ).  Because of the low voltage of each cell, ultracapacitors are utilized as multiple cells forming a module in series to attain the working voltage necessary to perform the work desired.  Low ESR ratings allow the cells in series to perform best and utilize the power of the ultracapacitor.  Low ESR is the performance goal in ultracapacitor manufacturing while still achieving long life.  LiCAP makes cells with very low ESR.


Question:  What is the difference between a welded seal ultracapacitor and a mechanical seal ultracapacitor?


Answer:   The biggest no-no in manufacturing ultracapacitors is allowing moisture in the process at any time.  Mechanical sealing comprises crimping of the ultracapacitor can onto the rubberized top of the lid that houses the terminals.  This is a fast production process that serves the industry well.  The drawback to a mechanical seal is that the connections are not as complete and the surface material will break down over time and exposure to heat.  


A welded seal process includes an aluminum lid which matches the can material that is interference fitted into the top of the can and then welded in place.  The fill hole is welded as is the  internal electrical connections .  This results in a premium product that has much lower Equivalent Series Resistance (ESR) and is more durable over time and with heat cycles.  LiCAP offers a full line of welded capacitors made with our industry leading Activated Dry Electrode.


Question:  How is the lifespan of an ultracapacitor or supercapacitor determined?


Answer:   When an ultracapacitor's measured capacitance is at 80% of original specification or when the Equivalent Series Resistance (ESR) measured in milliohms (mΩ) increases by 100% or more above  the specified rating, the capacitor has reached its useful life.  Cells are tested both by cycle testing and by operating them for 2,000 hours in an oven set at 65℃ to determine their lifespan.   LiCAP ultracapacitors use our patented Activated Dry Electrode to achieve industry leading durability as well as Low ESR.




 

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LICAP WIND TURBINE SOLUTIONS (pdf)

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LIC Application Information (pdf)

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ULTRACAP Application Information (pdf)

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