Double Damage is a supply in Tanki Online. It can be triggered by pressing "3" in the keyboard, and will instantly double the player's damage, for 45 seconds. It can be bought in the garage for 50 crystals each, starting at the rank of Sergeant, and is also available in the form of a drop box in-battle.
In addition to cut the self-healing time of Isida in half, due to the fact that the self-healing is affected by the damage-per-second, it also heals teammates twice as fast.
The appearance of the Double Damage looks like a green and red car battery.
It's good for turrets like shaft which can one or two shot other hulls.