How Are Smart Battery Used in Your Portable Devices?

What are smart batteries and how do they work?

Smart batteries are designed to be integrated into portable devices as part of a broader "intelligent power management system." This typically includes smart batteries, smart chargers, and a system management bus (SMBus) for communication between different components.

In a traditional portable device setup, any battery is just a "dumb" chemical power battery. Battery gauging, remaining capacity assessment, and any decisions about power usage are entirely informed by readings "obtained" by the host device. Such readings are largely speculative, usually based on voltage measurements from the battery through the host device, or (less accurately) through a coulomb counter in the host.

However, in an intelligent power management system, the battery can highly accurately "tell" the host how much charge it has left and how it wishes to be charged.

Generally, the battery, smart charger, and host device communicate with each other to maximize the product's safety, efficiency, and performance. For instance, a smart battery only requests charging when needed, rather than placing a constant, steady "drain" on the host system. As a result, smart batteries are more energy-efficient when charging.

Smart batteries can also tell the host device when to shut down based on their own assessment of remaining capacity, thereby maximizing "runtime per discharge cycle." This approach is far superior to using a fixed voltage cutoff as found in "dumb" systems.

Thus, host portable systems using smart battery technology can provide users with accurate, meaningful runtime information. This is clearly crucial for critical mission devices that