PORTER-CABLE 20V MAX Angle Grinder Tool, 4-1/2-Inch, Tool Only (PCC761B) $33.17@Amazon

Pretty good grinder, usually around $49.99. Lowest ever on Amazon apparently. Tool only. Yes, Black and Decker 20V batteries will fit it with a minor modification. You might need a grinder to modify, although that does have a potential for Catch 22 situation…
https://www.amazon.com/PORTER-PCC…B00FQ8OHBE