Integrated microbatteries are currently being developed to provide reliable low-noise voltage sources for system-on-a-chip applications by Jet Propulsion Laboratory (JPL). These microbatteries help provide localized current capacities or embedded power supplies at the chip level for space exploration. This paper presents a design approach for charging and discharging microbatteries. Maximum flexibility in terms of voltages and currents are also obtained through the use of a switching matrix. The microbatteries used for the design are rated at 50 nAh capacity and are solid-state lithium electrolyte based. The designs are built using Microwave Silicon-on-Insulator process. (C) 2004 Elsevier B.V. All rights reserved.