Over a period of 12 months my Lenovo T500 laptop battery life has deteriorated from about 2.5 hours to 1 hour.
Today the battery just suddenly died and the battery indicator keeps on flashing orange.
"A battery error has occurred. The battery cannot be charged. Replace the battery."
12.5 months battery lifetime.(Sanyo 42T4619)
In the Lenovo Power manager 3 softtware there is a link to buy a new battery.
For my model the Thinkpad T500 they list 40Y6799, 40Y6797 and not my 42T4619 as the replacement battery.