I’ve been cleaning up my home office and found 2 pretty old smartphones in a box, around 10 years old I’d say. I don’t have any old chargers to check if they still work so I’m unsure what sort of data is on there, if any, or if they still charge up even.

What are the chances I can safely dispose of them at a recycling center, without risk of anyone trying to check into the phone? None of them can have the battery removed so I don’t want to just smash them with a hammer.