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Either you're exaggerating, or your battery should be replaced. And take all the other things that influence the battery life into account, as mentioned a few posts up.

Not exaggerating at all. Now I havent actually timed battery life, I just stated what the calculation says. If it doesnt even read 8-9-10 hours, then most likely it wont last that long.

The only time I tried it was the second day I got it for calibration, it read 11 hours, but as soon as I moved the mouse to click on something it jumps down to about 6, it then got very low within 3-4 hours of use without backlit keyboard, 1 notch brightness, bt off, wifi on. I'm gonna give it another go very soon and see if I can get 10 hours. I never really expected to get 10, I know how advertising works but I atleast expected to get 6-7 good hours.
 
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