hey does anyone know what battery i need fro teh 2001 es300 key.

 

just open the key fob and take the battery to radio shack or something like that. sales person should help u find the right one.

 

Opened my non-functioning key fob (just remove screw and pry open) and sure enough, battery tested as dead. The battery was marked "BR 1216" and my local parts store has CR1216 (the same, I suppose).

Piece of cake.

Some later model Lexus' have CR1632 (possibly rare) which is a fair amount bigger and stronger.