Analysis of an automatic energy recovery system for partially spent batteries

This paper analyzes the performance of a system for automatic recovery and consolidation of energy from partially spent batteries. The objective for this system is to minimize the stockpile of batteries needed to run a suite of portable electronic devices on a daily, mission-oriented, basis. This system adapts to various battery types and allows the user to conveniently choose between charging and discharging specific batteries without changing the battery positions. The control algorithm is able to automatically select which secondary batteries should preferentially be charged. The control algorithm also continuously adjusts the discharging current of each battery according to its estimated state-of-charge. This concept is then verified by numerical simulation in the Virtual Test Bed (VTB) environment, which shows that the system is able to recover most of the energy from several partially spent batteries simultaneously. The effects of the discharge rate of the batteries on the overall system efficiency and the total discharging time are discussed.