Techniques for battery management of a device having multiple batteries are described herein. In one or more implementations, management for increased battery reliability involves assessing a combination of factors that influence a control policy for multiple batteries in a battery system. Based on the assessment, values of control parameters for power management of the battery system are set to reflect a tradeoff between performance and reliability. Then, at least one of battery utilization or charge current distribution is controlled in dependence upon the values that are set. Control of the battery system can be based in part upon differences in cycle counts for multiple batteries of a battery system for a device, such that cycle counts of the multiple batteries are managed for improved reliability.