Picture of a disassembled Duracell 9v battery. Below the terminal assembly is a clear plastic case where you can see six sets of stacked rectangular terminals and fillings.
I saw one of these at Target the other day in the $5-and-below section. Except it wasn’t a full phone, it was a nostalgia grab designed to be a wired “headset” for a cell phone with a headphone jack.
This 9v battery contained six cells stacked like a layer cake (lemmy.sdf.org)
Picture of a disassembled Duracell 9v battery. Below the terminal assembly is a clear plastic case where you can see six sets of stacked rectangular terminals and fillings.