I have an HP Elitebook 8440p and the battery is well past it's best before date.
The info on the battery says it's an UB-85 but when I search ebay/etc they list ones that say 8440p compatible but have a different model number. Is it because HP change specs slightly and therefore a revised battery will get a new model code?

The info on the battery says it's an UB-85 but when I search ebay/etc they list ones that say 8440p compatible but have a different model number. Is it because HP change specs slightly and therefore a revised battery will get a new model code?