Do disposable e-cigarettes have to be used up in one go?

No, disposable e-cigarettes can generally be used for one or two days before being thrown away. It doesn't matter if you take a few puffs a day. If you can't draw anything out at the end, it's gone. There are fewer disposable e-cigarettes now, probably because there are fewer users, so manufacturers produce fewer. Most people now use removable cartridge e-cigarettes. After smoking, you can just change a cartridge and continue smoking. You can see that most of the popular Yueke, Yuzu, Remo, and Xue+ are removable cartridges. You can choose any flavor, take a few puffs, and put them in your bag or pocket when you don't want to smoke. This is quite convenient.