If player A summons Batteryman 9-Volt and after that he activates Creature Swap, giving that 9-Volt to the opponent then 9-Volt will not be destroyed during the End Phase of this turn. This is because this End Phase is no longer "your End Phase" with "your" = "the current controller's".
Batteryman 9-Volt will be destroyed by its own effect during your opponent's next End Phase.
Batteryman 9-Volt will be destroyed by its own effect during your opponent's next End Phase.