Ultracapacitors are well suited to replace batteries in many applications. Voler Systems developed such a replacement for a company that makes RFID and wireless technology products. The battery replacement was cheaper with a longer life than a standard battery.
Ultracapacitors, also referred to as supercapacitors or double-layer capacitors, are electrochemical capacitors that have an unusually high energy density when compared to common capacitors. Conventional capacitors store only tiny amounts of energy. Ultracapacitors offer orders of magnitude higher energy storage. Larger ultracapacitors have capacities up to 5,000 Farads as of 2010, and 10 Farad capacitors cost only a few dollars.
Ultracapacitors offer some advantages:
The biggest advantage of the ultracapacitor over the battery is the simple charging circuit. A capacitor can be charged by just applying a voltage to it. A battery is easily damaged by overcharging, so it must be charged in stages, which is complex. The charging is usually controlled by a battery charging IC.
Ultracapacitors will not totally replace traditional batteries. When compared to traditional electrochemical battery, ultracapacitors shows these disadvantages:
Ultracapacitors are well suited to replace batteries in some applications but tradeoffs must be evaluated. For our RFID and wireless design, the ultracapacitor was a good alternative to a battery. It cost less than a battery and had a higher temperature range than a battery.