7.3 Feature Description

Information is accessed through a series of commands called Standard Commands. The Extended Commands set provides additional capabilities. Both sets of commands, indicated by the general format Command(), are used to read and write information in the control and status registers, as well as its data locations. Commands are sent from the system to the gauge via the I²C serial communications engine, and can be executed during application development, system manufacture, or end-equipment operation.

The integrated End-of-Service (EOS) Determination function is specifically intended for applications where the battery is rarely discharged, such as in eCall systems, uninterruptible power supplies (UPS), enterprise server backup systems, and telecommunications backup modules. In such systems, the battery may remain in a fully (or near-fully) charged state for much of its lifetime, with it rarely or never undergoing a significant discharge. If the health of the battery in such a system is not monitored regularly, then it may degrade beyond the level required for a system backup/discharge event, and thus fail precisely at the time when it is needed most.

The EOS Determination function monitors the health of the battery through the use of infrequent learning phases, which involve a controlled discharge of ~1% capacity, and provides an alert to the system when the battery is approaching the end of its usable service. By coordinating battery charging with the learning phases, the battery capacity available to the system can be maintained above a preselected level, which helps to avoid compromising the battery's ability to support a system discharge event.