Enhancing cellphone battery performance during GSM pulses

Patrick D. German, field applications engineer, AVX. Enhancing Cellphone Battery Performance during GSM pulses Through the Use of a Parallel Supercapacitor "With the constant addition of features and functionality, battery life and reliability are becoming increasingly vital to those who rely on their smartphones. The transmission signal requires quick pulses of current from the battery, potentially causing the instantaneous voltage of the battery to drop below the phone's minimum voltage of operation "The lifespan of rechargeable batteries can be a source of frustration for heavy users. Most rechargeable batteries require daily charging, which ultimately reduces the total life of the battery, since rechargeable batteries only have a limited number of charge/discharge cycles, and some, depending on battery chemistry, may form a memory, ultimately reducing charge. In this paper, we show that through the addition of a parallel supercapacitor that overall smartphone talk time and overall battery life can be extended. Tests were developed to simulate smartphone battery conditions during a transmitted conversation. The battery voltage was watched with both supercapacitor present and removed and run through the test until the battery had completely discharged. The data from these tests were gathered using a software control and data logger. The data from these tests showed that for all battery types, a parallel supercapacitor could extend overall battery life by supplying the majority of the current during power pulses. This benefit primarily manifested as a reduced delta-V between the loaded and unloaded battery, since the voltage of a battery will drop when high current is demanded. By keeping this voltage above the minimum operating voltage of the smartphone, the battery discharge time can be extended, charge cycles per year reduced, and overall battery life lengthened."