Um, @erkanostatic - the 12 watt/hour is more likely accurate. That is 1000mah at 11.1v. You can't cheat physics, sorry.
A little math to prove it - 1.1 hours at 5v and 2.3 amps = 1.1 hours at 10.6 watts = 11.66 watt hours of charge.
The 2.5 amps/hour reading is at 5V, BTW, not 11.1V.