Black & Decker battery and Charger (Stow Maries CM3)

I am asking for a battery and associated charger for a multi-purpose Quattro KC2000 tool. The battery that I have cannot now be charged by the charger but I cannot identify which of the two items needs replacing. If anyone has either one, or both of them, that is/are no longer needed (OR COULD BE BORROWED), I can then establish which of the items is faulty. The battery is a Black & Decker A9275 12V FIRE STORM and the charger is a Black & Decker model 486910-15 and both items were/?still-are used on other tools sold under the Black & Decker name. Thank you.