Supercapacitors Batteries
2.7V
5.5V
Example 4 Farad (4F) 5.5V 16ohm under £1
Supercapacitors have many advantages. For instance, they maintain a long cycle lifetime—they can be cycled hundreds of thousands times with minimal change in performance. A supercapacitor’s lifetime spans 10 to 20 years, and the capacity might reduce from 100% to 80% after 10 or so years. Thanks to their low equivalent series resistance (ESR), supercapacitors provide high power density and high load currents to achieve almost instant charge in seconds. Temperature performance is also strong, delivering energy in temperatures as low as –40°C.
On the other hand, supercapacitors are offset by their low energy density. Thus, they can’t be used as a continuous power source. One cell has a typical voltage of 2.7 V; if higher voltage is needed, the cells must be connected in series.
Ultracapacitors
Ultracapacitors vs. batteries
Ultracapacitors store energy in an electric field, rather than in a chemical reaction like batteries. This allows them to charge and discharge much faster than batteries. They can also survive up to a million charge and discharge cycles, offering much longer lifecycles. Ultracapacitors have little or no internal resistance (down to 0,12 mΩ), allowing them to work at close to 100% efficiency. They are also significantly lighter than batteries and generally don’t contain harmful chemicals or toxic metals.
Graphene SkelCap industrial cells are available at 2,85 V from 500 to 3200 Farad cells, with a very low ESR.