http://www-307.ibm.com/pc/support/site.wss/document.do?sitestyle=lenovo&lndocid=BATT-LENOVO via www.lenovo.com/batteryprogram

IBM and Lenovo sold these Sony batteries in systems listed below between February 2005 and September 2006. Customers who bought one of the following systems may have a battery subject to this recall:

ThinkPad R Series (R51e, R52, R60, R60e)
ThinkPad T Series (T43, T43p, T60)
ThinkPad X Series (X60, X60s)

Additionally, since these batteries can also be used with ThinkPad T4x Series or ThinkPad R5x Series systems, customers who ordered an extra battery or received a replacement battery for any ThinkPad T4x or ThinkPad R5x Series notebook PC between February 2005 and September 2006 may also have a battery subject to recall.

If your battery has been recalled, to continue using your ThinkPad notebook PC safely:

Turn off the system
Remove the battery
Power your system using an AC adapter
Lenovo apologizes for the inconvenience caused by this issue. Shipment of quality products always has been and continues to be the foremost concern.