9 Volt

9 Volt is a passive item.

Effects

 * Fully charges the current activated item upon first pickup.
 * If the current activated item has a recharge time of more than 1 bar, then it will grant 1 bar of charge whenever the item is activated.
 * If the current activated item has a recharge time of 1 bar, then it will change the item to have a timed recharge of 15 seconds. The recharging of the item only triggers so long as there are enemies present in the room in any fashion. Empty rooms do not cause recharging to start.
 * A fly or spider spawned in a cleared room will also cause recharging to start (including friendly ones, making it very effective when used with Guppy's head)
 * Taking damage from entering/leaving a Curse Room causes recharging to start as well.
 * If the current activated item has a real-world unit-based recharge time, the effect of the 9 Volt may vary.

Interactions

 * Sharp Plug - Renders the Sharp Plug unusable. Sharp Plug can only be used if the item is at 0 charge, but 9 Volt instantly gives +1 charge to the item upon activation.

Synergies

 * AAA Battery - Even faster item charging (9 Volt gives 1 extra bar after any item use, while AAA Battery reduces the number of bars required for using the activated item).
 * AAA Battery + The Book Of Belial or other 3-room charge items - Fills the entire gauge in a single room, effectively granting the opportunity for the item to be used every room (e.g.: in practice, a constant damage bonus from the Book of Belial).
 * The Battery - Charges faster and stores an extra level of charge.
 * The Candle - The Candle starts at half charge after use.
 * Red Candle - Red Candle recharges quicker than normal.
 * Wooden Nickel - Infinite coins (if you have the time).
 * Brown Nugget - Brown Nugget starts at half charge after use.

Trivia

 * This item is used in When Life Gives You Lemons (challenge #12), Beans! (challenge #13), and It's in the Cards (challenge #14).

9 Volt