The Energy Tank is the best recovery item in the game, surpassing by a huge margin the previous holder of that title, the Heart Container. This is because it is able to reduce the character's damage meter all the way down to 0%, no matter how high it is. When this item is grabbed, the character will hold it over its head, akin to using an Assist Trophy, until fully healed; naturally, the player is extremely vulnerable while healing, and one hit of any strength will cause the Energy Tank to be dropped and disappear. This means the more damage the character has to recover, the more time he/she will be vulnerable while healing. The design of Energy Tank in SSF2 comes from Mega Man 2, its debut game.
The Energy Tank was the first kind of tank to ever appear in the Mega Man games. It first appeared in Mega Man 2, and since then has been present in almost all games from the original Mega Man series. It fully recovers the health of the user, doing exactly the same in SSF2. Because of that, Energy Tanks are the second rarest and hardest item to be get, just after the more useful 1-Up. Energy Tanks can be stocked in the Mega Man games, the maximum number of Energy Tanks that could be carried was initially four and was increased to nine for Mega Man 3 to Mega Man 6, but was reduced back to four for the Game Boy games and Mega Man 7. It returned to nine for Mega Man 9 and 10. The Energy Tank also appears in the Mega Man ZX series, where only one can be carried at a time.