BM boasts a very large array of older and newer refurbished laptops on their website ibm.com. Look for “Notebooks: IBM Certified Used Equipment.” There you can buy any of dozens of models and variations, for hundreds of dollars less than new models. IBM inspects all of their returned laptops (including the batteries, as with most factory-refurbished laptops), makes sure they up and running at top speed, and repackages them for resale.
Most IBM refurbished laptops are ThinkPad A-series or T-series. A-series are heavier, but much more powerful, since they are designed to replace desktop computers. They can handle everything your desktop computer used to handle, plus they fit in your laptop carrying case. A-series models are generally more expensive than those in the T-series.
IBM T-series notebooks are made to be a little more powerful and a lot lighter and smaller than the A-series models. They were introduced to satiate those who were demanding a more portable model, so they could take all of their work with them wherever they went. Since they are a newer series, and because they are starting to replace the A-series, the T-series models are a bit more expensive.
As with most laptops refurbishing factories, IBM offers a three-month warranty and guarantee on all of their refurbished laptops – including for the battery. Third-party refurbishers also offer a ninety-day warranty, but with no warranty on the battery.