I have large amount (>50) of old disposable vapes with lipo cells. How do I check which cells are still good?

Hi, because I have heavy smokers in my family, I have gotten quite some disposable vapes from them, mostly around a year ago.

I wonder, what is best way to check, if their lipo cells are still usefull. Will just checking if voltage is in safe range enough?

Other than multimeter i also have microcontroller based lipo charger, that has internal reistance checking option.

Then, can I just parraler connect cells to make bigger one if I need or is there something more to it?

thank you in advance for advice