From: Albuquerque, NM
Replacement chits are used to restore units that have received 'hits' to their original strength. Units can take hits for a variety of reasons, movement during harsh weather, being out of supply and combat.
The number of hits that a single chit can recover is somewhat non-deterministic, but a good rule of thumb is that a single chit can replace 10 hits.
You and the rest, you forgot the first rule of the fanatic:
When you become obsessed with the enemy, you become the enemy.
Jeffrey Sinclair, "Infection", Babylon 5