Is Replenishing Ammo for Vehicles & Turrets Free?

At the end of a mission there are charges (tech/materials) for replenishing ammo for the units. However, I have never seen a charge showing for replacing ammo for vehicles and turrets. Are they freebies? Or is the tech/materials taken out of the bank secretly and without our knowledge?

I checked and it is free, Just waiting ammo replenished