Without supercaps, cell phone and tablet batteries typically act like a shrinking tank of water. When these tanks are drained rapidly, they typically have less energy storage capacity. Over time, this diminishes the run time of the device.
Using a supercap in conjunction with a Lithium Ion battery in a mobile applications provides better regulation of the peak current. In doing so, peak current drain is better controlled and the energy capacity of the battery is preserved over a longer period of time.
There basically three configurations for using supercaps in a mobile application:
- Parallel (similar to vehicle)
Connected in-line with the battery, the parallel setup features low-cost and simplicity. By separating the supercap from the battery, devices will have the longer battery life but it depends upon the application types. Each of the configurations deliver:
- Longer device run-time on one charge
- Smaller/thinner devices
- Lower cost energy storage
- Longer battery life
- Reduction of high repeated charge/discharge currents
Testing of typical use case on a mobile device-- consumed 6W 40 seconds 40W 10 second-cycle—reveals the advantage of combining supercaps with a battery. The battery was drained of its energy in 0.4 hours but when a supercap was added, the system run time was improved to 2.12 hours, marking a 400 percent increase by limiting the battery discharge to a 1C rate.
The bottom line is that supercapacitors provide improved battery performance in mobile devices in compelling ways:
- Effectiveness of adding supercapacitors to a Li-Ion battery has been shown for multiple power profiles.
- Duty cycle and peak-to-baseline power profile are critical to the value of adding supercapacitors.
- Supercapacitors offer a cost effective and volume effective way to significantly extend run time.
- Supercapacitors are a long life,