The battalion and its detachments engaged in many skirmishes while serving with the Department of Western Virginia before becoming engaged at the Battle of Cloyd's Mountain where the battalion's strength was reported as 183 officers and men, suffering four killed and eleven wounded. With the rest of Colonel John McCausland's forces the Forty-Fifth was engaged along the New River before turning east to fight at the Battle of Piedmont with 175 men and the rest of the Valley Campaigns of 1864. Like most other units of Early's army, the 45th Battalion surrendered after the defeat at Waynesboro.