Shell Bell VS. Leftovers.

Question

Which one? Which is better? Refills more HP?

Answer 1

Shell bell refills HP based on 1/8 ( One eighth ) of the damage you deal.
Leftovers restores 1/16 of your maximum HP every turn.

If you can guarantee that you're going to be doing a lot of damage, Shell Bell can be useful. But most of the time the healing is needed for bulk, and most bulky pokemon won't be doing as much attacking. Leftovers is more common, because is reliable to last every turn.

Answer 2

Leftovers. Shell Bell restores up to 1/8 of the damage dealt to a Pokemon.Leftovers provide constant and reliable healing.

Answer 3

generally:
shell bell for a tank
leftovers for staller

but if your pokemon has higher hp than average, go for leftovers
Also, if you're gonna make lots of switching, or use stat raising moves, use leftovers also

Answer 4

This Site gives good explanations of when which is better.