Blaster power packs, also known as energy packs, functioned as energy reservoirs that provided the necessary power for a blaster to operate. As a sign of respect, the 61st Mobile Infantry of the Rebel Alliance would empty power packs during the funerals of their deceased comrades. In 3 ABY, during the Battle of Hoth, Private Emon Kref utilized an A295 blaster rifle that was powered by a blaster power pack prone to ejection, a flaw Kref tried to remedy by using tape.
The concept of blaster power packs was initially introduced in the 2015 book Battlefront: Twilight Company, authored by Alexander Freed. Later, the Rogue One: A Star Wars Story novelization, also penned by Alexander Freed, referred to these devices as energy packs.