Payday: The Heist contains medic and ammo bags which replenish health and ammunition, respectively. After a while, these bags become depleted and vanish. I haven't been able to figure out if a bag disappears after it has been used a certain number of times, or if it disappears after replenishing a certain amount of health or ammo.
I ask because if the first case is true, then I should avoid using bags when I'm at 75% or higher on health / ammo, because I'll be effectively wasting a use. If the latter is true, then I can use bags whenever I want, because I won't be hurting any other members of my team.
Do medic and ammo bags run out after a certain number of uses, or after a certain amount of health / ammo has been dispensed?"