Half Life was released by Valve in 1998 and follows scientist Gordon Freeman in the powered Hazardous Environment suit, better known as the HEV suit. Its chargers and suit stations became familiar to players because keeping suit power topped up was vital in combat. Short suit system sounds like SuitChargeOk were later ripped from the game files and shared on soundboards and in video edits. Its continued use comes from nostalgia for the original game and from how clearly this one brief confirmation still signals sci fi armour coming back online.