When a mage uses their ability, they lose all of their charges as soon as they begin evaluating their ability's effect(s).
Example: Mist (WE) uses her ability Exalted Brand to cast Feedback Aura (Cast: Deal 3 damage. If you have 4 or more charges, deal 3 additional damage). Because Mist cast the spell using her ability, she discards all of her charges, so Feedback Aura only deals 3 damage.
