Abstract: An energy storage module (ESM) for spacecraft has at least one battery. The ESM has a first interface to at least one string of solar cells configured for charging of the battery, a second interface to a spacecraft for outputting power from the battery and a third interface for communicating to other spacecraft modules. The ESM has a charge controller coupled with the battery and the first, second and third interface. The charge controller has a microprocessor with firmware to autoconfigure a system configuration of the battery and, in an embodiment, connections of strings of solar cells to the charge controller, and to present determined configuration and state of charge to other components of the spacecraft. In embodiments, the microprocessor has firmware for contacting another parallel-connected ESM and to present total power available in both ESMs to other modules of the satellite, and charging of the batteries can be coordinated.