Battery Cycle Life & Performance Optimization for Small and Medium-Sized Robotic Platforms

When batteries with different capacity, age, and state of health are combined in a single pack, the usable capacity, performance, and cycle life of the batteries are seriously degraded. The Army requires a solution that performs real-time balancing with the goal of improving performance and extending battery lifetime. ThermoAnalytics Inc. and Bloomy Controls Inc. propose a system that applies load-balancing, selective current control to regulate the charge and discharge of each battery based on lifetime estimation from a predictive battery degradation algorithm, running in real-time and integrated into a micro-controller in the battery management system. An optimal power profile will be applied to each battery to cycle the stronger batteries more and the weaker batteries less. Individual battery switching will be used to achieve the maximum possible capacity and to avoid circulating current at low- or no-load conditions. “Smart cradles” will be fabricated to hold each battery and provide the current control into and out of each battery. Each cradle will also monitor and communicate the battery’s current, voltage, state of charge, state of health, and other available internal measurements. Phase I will culminate in a proof-of-concept demonstration of the control system and balancing hardware using BB-2590 batteries.