cheaper price, but not that powerful

I bought the battery for my X200s. At first glance, everything looks good. The capacity takes about 2 hours by about 50%. This gives us hope that 4h operating with battery would be possible. In fact, it is so that the capacity from 50% is consumed about twice as fast. The possible battery life is thus just under 3 hours, which rather disappointed considering the size of the battery.
The original LENOVO battery will cost many times that part (which is identified by the X200s as a product of SANYO). Seen in the price / performance ratio is much better than the Lenovo battery.