Instax Mini 11 (and typical Mini AA models)
Fujifilm Instax Mini 11 takes two AA alkaline batteries (LR6). Fujifilm’s specs disallow manganese cells. Open the Mini 11 device page for compartment and caveats.
Other Mini variants (8 / 9 / 12 and similar) often use AA as well — confirm each model on Fujifilm’s specs before assuming the same count or chemistry rule.
Film pack is separate from the AA cells
Instax Mini film packs are the consumable for photos. The AA cells power the camera electronics and eject mechanism. Do not confuse the battery door with the film door.
Not Polaroid Type E packfilm
Classic Polaroid 600 / SX-70 style packs often carried an integrated battery in the film pack (Type E architecture). That is not the Instax AA pattern. Do not shop “camera battery” generics and expect them to replace a Polaroid pack.