Do I need a different charger for different battery types?

If you currently have a rapid charger (1 to 3 hour) you can use that charger with all three battery chemistries: NiCD, NiMH & Li-Ion.

If you have a slow/overnight charger you can only use it with NiCD & NiMH batteries. If you want to use Li-Ion batteries instead you will have to purchase a rapid charger.