Medkit

Info
This upgrade increases the rate at which your tank regenerates hit points.

The delay between your last attack or the last time you took damage and when regeneration begins remains unchanged; Medkit only increases how quickly you recover health once you begin regenerating.

Common
+30% faster regeneration

Rare
+40% faster regeneration

Epic
+50% faster regeneration

Strategy
Regarded by some as the worst upgrade in the game, a Medkit will generally prove lackluster or not make any difference at all during a match.

Use a Medkit on tanks that don't mind holding back or that can get out of harm's way, such as long-range tanks (like Titan or Tower), tanks with evasive options (such as Ninja or Shift) or tanks with high health that will need to hold down the front line (Phoenix, Scorpion).

Note that Kong regenerates health while it off-screen during its special attack, and so can possibly benefit more easily from this upgrade than other tanks.