Comment about Nickel Cadmium (NiCd) batteries being old(ish) technology is valid – they self discharge while a Lithium battery will stay charged (unused) for much longer.
I recently bought an 18v Bosch cordless with lithium batteries, cost me 80 something quid from Amazon but it was cheaper than replacing my old battery pack that got fried when my old charger expired
Been very good so far, but I think they are not the best nowadays as has been mentioned – Ok for light domestic use (I have a bench drill now for the more serious stuff…)
So I now have a Black and Decker cordless motor looking for a new use <g>
Chris