Some lenovo laptops may have defective batteries:

http://www.reghardware.co.uk/2009/08...battery_issue/

The issue affects ThinkPar R60, R61, T60, T61, X60 and X61 machines sold worldwide. It manifests itself as a sudden drop in the battery charge displayed by Windows or by a very short battery life.
You can download a testing tool here:

http://download.lenovo.com/lenovo/co...ndingPage.html

They will replace the defective ones free of charge.


N.B. This is NOT a safety issue, it just affects performance.