Literally anything. Even the things I still have that use AA and AAA batteries (of which the newest things are my VR controllers which is so stupid…), I have rechargeable lithium ion AAs and AAAs for so I don’t have to constantly buy batteries.
As a kid, tho, I loved 9volts because they had the best connectors. I could take a little battery powered motor apart, glue it to some legos and use it to make machines that moved or did stuff. I almost killed myself once wondering what would happen if I took the cord from a busted fan, wired it to the 9volt battery motor and the plugged the cord into the wall outlet.
Literally anything. Even the things I still have that use AA and AAA batteries (of which the newest things are my VR controllers which is so stupid…), I have rechargeable lithium ion AAs and AAAs for so I don’t have to constantly buy batteries.
As a kid, tho, I loved 9volts because they had the best connectors. I could take a little battery powered motor apart, glue it to some legos and use it to make machines that moved or did stuff. I almost killed myself once wondering what would happen if I took the cord from a busted fan, wired it to the 9volt battery motor and the plugged the cord into the wall outlet.
It blew up the motor and started a fire. 🤣
It’s the best connector because you can lick it