Design of a smart battery system for laptop computer

Abstract

The performance and lifespan of Li-ion batteries are closely related to the quality of their charger. To enhance the charger's performance, the Smart Battery System (SBS) Specification presents one element of a complete system solution for rechargeable batteries used in portable electronic equipment. The SBS features charging characteristics that are controlled by the battery itself, in contrast to a charger with fixed charging characteristics that will work with only one cell type. Therefore, the smart battery/smart battery charger combination provides distinct advantages in system safety, performance, and cost. In this chapter, a level 2 SBS is developed and implemented. The power stage is implemented using a level 2 SBC IC ISL88731 from Intersil Corp., and the host controller is realized by using the dsPIC microcontroller from Microchip Corp. The five-step constant-current charging pattern is implemented in the host controller. Comparing to conventional constant-current-constant- voltage (CC-CV) charging pattern, five-step constant-current charging algorithm has the advantages such as higher charging efficiency and shorter charging time. © 2013 Springer Science+Business Media New York.