Pexy13

Greetings I have a problem with my drills batteries because they are old and don't hold charge any more like they used to (no torque and speed). The drill itself is in good shape so i was thinking about buying a new LiPo battery and replacing the connectors and stuff to make it work with my drill. The drill is Bosch GSR 12-2 PRO. Is this a good idea and would it work normally or is it more beneficial to buy a new drill? Thanks