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