Title: Battery Charging System and Circuit Fundamentals for Portable and IoT Devices
Ayman Fayed, The Ohio State University, USA
This tutorial will introduce the basic operation and characteristics of various battery cells commonly used in portable and IoT devices, including their charging/discharging profiles, self-discharging, internal impedance, charging cycles, and the effect of ambient and operating conditions on all these aspects. This will be followed by presenting the most common charging schemes used to charge single- and multi-cell battery stacks, including the constant-current constant-voltage charging scheme and the pulse charging scheme and the specific safety hazards and consideration for Li-Ion batteries. The tutorial will then present the circuit implementation of linear and switching battery charger topologies, fuel gauging circuits, and cell-monitoring and cell-balancing techniques. The tutorial will be concluded by presenting various implementation and performance examples of commercial battery charging integrated circuits and a discussion of practical considerations for portable devices.