Watch Battery is a trinket in The Binding of Isaac, added in the Afterbirth DLC.

Increases the chance of a random battery pickup spawning after clearing a room by 6.67%.

Increases the chance of random pickups being replaced with batteries by 2%.

Has a 5% chance to add an extra charge to Isaac's active item upon clearing a room.

This page shows the latest information as of the new Repentance+ (Online Co-op) DLC.
To see information about this trinket for the previous Repentance version, check this page instead.

The following tags are applied to this trinket:

The following special synergies and interactions for Watch Battery have been documented.

* Note that not all possible synergies and interactions are listed here.

Below is the Internal Item Description as shown in-game.
Note that some stat changes are not displayed here. Please see the main description for the full effects.

Watch Battery

• 6.66% increased chance of lil' batteries spawning
• Chance to replace a room reward with a lil' battery
• 5% chance to gain an extra charge on room clear
• Golden Trinket (without Mom's Box): 5% chance to gain 2 extra charges on room clear
• Mom's Box: 5% chance to gain 2 extra charges on room clear
• Mom's Box + Golden Trinket: 5% chance to gain 3 extra charges on room clear
• Jacob's Ladder: Increases the range of sparks

• Check out the trinket description on the external Isaac Wiki.