B&d Chargers Schematic Can I Leave Black & Decker Versapak Batteries In The Charger For Extended Periods Of Time?

Can I leave Black & Decker Versapak batteries in the charger for extended periods of time? - b&d chargers schematic

I bought a Dustbuster VersaPak conclusive and left the batteries in the empty and load, even during the months of disuse. The batteries are toast and you can not hold a load of more than 2-3 minutes. I bought new batteries, but can not find the original manual Dustbuster. Should I vacuum after the Dustbuster costs? How long does it take? VP7240 Dustbuster but my B & D does not have this online manual.