The Accelerate Charge System (瞬間突撃システム Shunkan Totsugeki Shisutemu, lit. "Instant Charge/Assault System"), commonly shortened as A.C.S (Ａ.Ｃ.Ｓ Ē Shī Esu), is a Device upgrade that increases its capacity for high-speed charge attacks.
The A.C.S is generally available under the Full Drive of a Device, e.g. Raising Heart Exelion in Exelion/Exceed Mode and Mach Caliber in Gear Exelion. However, it is revealed in Magical Girl Lyrical Nanoha Strikers Official Fan Book that the Buster Mode of Raising Heart Exelion also bears such system.
The activation of Raising Heart's A.C.S causes her head to sprout a number of energy wings and generates the semi-materialised Strike Flame at her tip. The butt of Raising Heart manifests a rocket booster which allows Nanoha to travel at great speed. In StrikerS, this system is improved as part of the reinforcements to Raising Heart's frame, displaying a larger heatsink along with greater speed and power. It now possesses an attack called A.C.S Driver, allowing Nanoha to travel at such speed that a swarm of Type III Gadget Drones are destroyed by her shockwave.
Following Devices implement the Accelerate Charge System:
|Device||Magic system||Device type|
|Mach Caliber||Modern Belka||Intelligent Device|
|Raising Heart||Midchilda||Intelligent Device|