No, you can't. Yeah, this one's a common thought, but it's a definite no-go. Use power tools only with the specifically designated DeWalt battery packs.
Using any other battery packs may create a risk of injury and fire. The charger rule is the same: charge only with the charger specified by the manufacturer. A charger suitable for one type of battery pack may create a risk of fire when used with another.
HEADS UP: Also, when the battery pack is not in use, keep it away from other metal objects like paper clips, coins, keys, or nails. Shorting the battery terminals together can cause burns or a fire.