Tiny, Accurate Battery Gas Gauges with Easy-to-Use I2C
Interface and Optional Integrated Precision Sense Resistors
Christoph Schwoerer, Axel Klein and Bernhard Engl Imagine your daughter is catching her first wave on a
surfboard and your video camera shuts down because the
battery—reading half full when you started filming a few
minutes ago—is suddenly empty. The problem is inaccurate
battery gas gauging. Inaccurate fuel gauging is a common
nuisance as many portable devices derive remaining
battery capacity directly from battery voltage. This method
is cheap but inaccurate since the relationship between
battery voltage and capacity has a complex dependency
on temperature, load conditions and usage history.
More accurate battery gauging can be
achieved by monitoring not only the
battery voltage but also by tracking the
charge that goes in and out of the battery. For applications requiring accurate
battery gas gauging, the LTC2941 and
LTC2942 coulomb counters are tiny and
easy-to-use solutions. These feature-rich
devices are small and integrated enough to
fit easily into the latest handheld gadgets.
The LTC2941 is a battery gas gauge device
designed for use with single Li-Ion cells …