Daisy-chain communication bus and protocol

In some embodiments, an apparatus is provided that includes a bi-directional communication bus, a set of battery sections connected to the bi-directional communication bus, and a battery manager circuit bi-directional communication bus. Each of the battery sections of the set has a clock circuit. The battery manager circuit is configured to communicate with the set of battery sections via the bi-directional communication bus using a synchronous master-slave communication protocol, in which symbols transmitted by the battery manager circuit include respective timing trigger segments and respective data segments. Each battery section of the set of battery sections is configured and arranged to adjust a frequency or a phase of the respective clock circuit of the battery section, relative to timing of the timing trigger segments.