This Article 
 Bibliographic References 
 Add to: 
Discharge Current Steering for Battery Lifetime Optimization
August 2003 (vol. 52 no. 8)
pp. 985-995

Abstract—Portable and wearable computers can be powered by different combinations of two or more battery packs to give the user the possibility of choosing an optimal compromise between lifetime and weight/size. Recent work on battery-driven power management has demonstrated that sequential discharge is suboptimal in multibattery systems and lifetime can be maximized by distributing (steering) the current load on the available batteries, thereby discharging them in a partially concurrent fashion. Based on these observations, we formulate multibattery lifetime maximization as a continuous, constrained optimization problem, which can be efficiently solved by nonlinear optimizers. We show that significant lifetime extensions can be obtained with respect to standard sequential discharge (up to 160 percent), as well to previously proposed battery scheduling algorithms (up to 12 percent).

[1] Compaq IPAQ PDA Overview and Characteristics, index.html, 2002.
[2] HP OmniBook 500, professional/ultra_portableindex.htm . 2000.
[3] L. Benini et al., "Discrete-Time Battery Models for System-Level Low-Power Design," IEEE Trans. VLSI Systems, vol. 9, no. 5, 2001, pp. 630-640.
[4] T. Martin and D. Sewiorek, Non-Ideal Battery and Main Memory Effects on CPU Speed-Setting for Low Power IEEE Trans. VLSI Systems, vol. 9, no. 1, pp. 29-34, Feb. 2001.
[5] C.F. Chiasserini and R.R. Rao, "Energy Efficient Battery Management," IEEE J. Selected Areas in Comm., vol. 19, no. 7, 2001, pp. 1235-1245.
[6] D.N. Rakhmatov and S.B.K. Vrudhula,"An Analytical High-Level Battery Model for Use in Energy Management of Portable Electronic Systems," Proc. 2001 IEEE/ACM Int'l Conf. Computer-Aided Design, IEEE Press, 2001, pp. 488-493.
[7] Q. Wu, Q. Qiu, and M. Pedram, "An Interleaved Dual-Battery Power Supply for Battery-Operated Electronics," Proc. 2000 Conf. Asia and South Pacific Design Automation, IEEE Press, 2000, pp. 387-390.
[8] L. Benini et al., "Battery-Driven Dynamic Power Management," IEEE Design and Test of Computers, vol. 18, no. 2, 2001, pp. 53-60.
[9] L. Benini et al., "Extending Lifetime of Portable Systems by Battery Scheduling," Proc. 2001 Conf. Design, Automation and Test in Europe, IEEE Press, 2001, pp. 197-203.
[10] D. Linden, Handbook of Batteries, second. ed. Hightstown, N.J.: McGraw-Hill, 1995.
[11] M. Glass, Battery Electro-Chemical Nonlinear/Dynamic Spice Model Proc. Energy Conversion Eng. Conf., pp. 292-297, Aug. 1996.
[12] A. Smailagic and D.P. Siewiorek, "System Level Design as Applied to CMU Wearable Computers," J. VLSI Signal Processing Systems, vol. 21, no. 3, 1999, pp. 251-263.
[13] D. Rakhmatov, S. Vrudhula, and C. Chakrabarti, "Battery-Conscious Task Sequencing for Portable Devices Including Voltage/Clock Scaling," Proc. 39th Design Automation Conf., ACM Press, 2002, pp. 189-194.
[14] K. Billings, Switchmode Power Supply Handbook. McGraw-Hill, 1999.
[15] RFP15N05L Medium Power NMOS Transistor Datasheet, , 2002.
[16] TSI-3, 3S3R0 DC/DC Step-Down Converter Datasheet, , 2000.
[17] 1HR-AAAU Sanyo Battery Datasheet,, 2000.
[18] M. Pedram and Q. Wu, Battery-Powered Digital CMOS Design Proc. Design Automation and Test in Europe, pp. 72-76, Mar. 1999.
[19] K. Schittowski, NLQPL: A FORTRAN-Subroutine Solving Constrained Nonlinear Programming Problems Annals of Operations Research, vol. 5, pp. 485-500, 1985.
[20] Lithium-Ion Rechargeable Battery Catalog,, June 2001.

Index Terms:
Battery-operated electronics, dynamic power management, low-power design.
Luca Benini, Davide Bruni, Alberto Macii, Enrico Macii, Massimo Poncino, "Discharge Current Steering for Battery Lifetime Optimization," IEEE Transactions on Computers, vol. 52, no. 8, pp. 985-995, Aug. 2003, doi:10.1109/TC.2003.1223633
Usage of this product signifies your acceptance of the Terms of Use.