Why is the battery level incorrectly detected in a Linux laptop?

Question

linux

It costs ElementaryOS Luna (a derivative of Ubuntu 12.04).
Everything in the work suits except for one bug - the charge level on the panel is displayed incorrectly. For example, a widget can show a little less than half the charge, but the laptop can instantly cut off.
I wanted to clarify how this thing can be configured and calibrated? What utilities can be used to monitor battery status and charge level?

Answer 1

A common bug in ubuntu: http://forum.ubuntu.ru/index.php?topic=222228.0

Answer 2

What's a laptop? Laptop mode tools cost?

Answer 3

It probably shows the "real" battery charge, and not the one that everyone is used to. That is, taking into account the wear and tear of the battery, its actual capacity, relative to the maximum capacity.
I could be wrong, but I've experienced this on Linux.