"Battery" is the opening track of Metallica's 1986 album Master of Puppets. As with the opening track from Ride the Lightning, Battery begins with a slow, clean guitar part. In this case, as many as four acoustic guitars are layered harmonically before the drums and bass come in with distorted guitars playing a more melodic version of the acoustic part. This lasts until 1:06, when the guitars cut into a very fast minimalist thrash metal riff that is the basis for the rest of the song. In live concerts, the beginning is not played by the band but instead the actual recording is used (recently dropped 1/2 step in key, since the band tunes 1/2 step down).

In keeping with the general "control" theme of Master of Puppets, the lyrics of "Battery" discuss the control that anger can have over one's behavior. The title refers to "battery" in the sense of "assault and battery", as shown by these lyrics: "Smashing through the boundaries / Lunacy has found me / Cannot stop the battery". The song is an indirect tribute to the Old Waldorf Club in San Francisco on Battery street.

"Battery" is still an almost constant part of the band's live set list, frequently as the opening or closing song. In some cases, it is also used as a song before the intermission. When played, the song may stop before the interlude, and James Hetfield asks the crowd "Are you alive?... How does it feel to be alive?" and followed by the solo played by Kirk Hammett. During the chorus of the original version, bassist Cliff Burton can be heard roaring the backing vocals each time Hetfield says the title.

In the live version of the song played on the Live Shit: Binge & Purge album, intros to the songs "No Remorse", "Ride the Lightning", and "So What?" are played in the song. When performed with the San Francisco Symphony in 1999, the intro up to the thrash riff was instead played by string players in the symphony, utilizing pizzicato in the beginning (the original acoustic) then with bows for the rest.