Just check my signature, for fuel gauge calibration and bq27200.sh download location. BTW, link to instruction is also on first post of this thread, close to very beginning of it, written in big bold letters

Anyway, I really think it is software issue. for GUI, fool-proof method, just use package (from extras repositories, not sure if -testing, -devel or basic one) batterygraph or batteryeye. Monitoring usage in standby or during certain activities may show what is eating battery life.