Typically a lance is used once in a battle, you charge, the lance either becomes embedded in your target, breaks or misses, in either case you drop it and draw a sidearm for close quarters fighting. There have of course been cases where lancers or knights have wheeled around, gone back to their original starting point, rearmed and charged again but I would consider this an exception to the rule. Typically a charge was intended to be the deciding move in a battle, shattering all or a crucial part of the enemy formation and thus ending the battle.