In Combat Simulation or Area Patrol, in addition to consuming Battery Charge to fight and earn rewards, you can also use the Ether Battery auto-battle feature to obtain mission rewards instantly.

On the Combat Simulation or Area Patrol screen, press the Auto-Battle button, then press Auto-Battle again to instantly receive the rewards for a single 60 Battery Charge Combat Simulation or Area Patrol mission.

Ether Batteries can be acquired via the New Eridu City Fund or through item crafting and other methods.