A Data Transmission Control to Maximize Discharge Capacity of Battery

Abstract

In machine-to-machine communications, battery life is so critical that many researchers make efforts in the areas of system configurations, network topology, protocols and so forth. This paper proposes a data transmission control method that focuses on well-known electrochemical characteristics of batteries. An objective of the proposed method is to increase the discharge capacity as the total amount of available current from a fully charged battery. From Peukert's law, it is known that increasing the average level of current extracted from the battery decreases the discharge capacity. Pulse discharge by insertion of rest time periods, however, has an effect equivalent to that the average level of current decreases. Furthermore, since such pulse discharge needs to be managed in consideration of the status of data transmission and network congestion, we suggest a novel data transmission control method aiming at an effective pulse discharge to maximize the discharge capacity with sufficient quality of data transmission. The proposed method can be implemented as a function to manage the size of data and the timing of data transmissions. A prototype terminal that employs the proposed method was developed with a small-capacity lithium-ion secondary battery. Experimental results show the effectiveness of pulse discharge in the application of the proposed method to the prototype terminal. Furthermore, an analytical investigation provides appropriate operational parameters to enhance the effectiveness.