Wirebook › Glossary › Battery gauge
What is a battery gauge?
In one sentence: The little chip that works out a device's battery percentage by counting charge in and out and watching the voltage.
A little more
The battery percentage on a screen is an estimate made by a small chip called a fuel gauge. It counts the charge going in and out, and corrects that count using the battery's voltage, temperature and how worn it is.
Cold fools it: the voltage sags under load, so it can think the battery is emptier than it is, and the number may drop suddenly then climb back when the device warms up. Using the battery from full to nearly empty now and then helps some gauges recalibrate, but that isn't needed often.
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