The Energy Balancer is a technology that allows the player character to reload the weapon with less energy by collecting a Weapon Energy pickup with a weapon that requires no energy or that has the full energy bar. This device allows to reload a wasted weapon without having to equip it first, although to fill a specific weapon, it needs to be equipped.
In the official games, this object was introduced in Mega Man 6 as an object given by Proto Man in a secret area (located in Tomahawk Man's stage). It reappears in Mega Man 7, being obtainable by using Rush Search (located in Shade Man's stage) or buying it from Auto. Further games would include this item either by default or in a shop.