This cordless chain saw is designed for cutting off branches. It is powered by an environment-friendly lithium battery. Longer runtime can be provided by combining with the high capacity backpack battery, allowing the chain saw to be operated in environments where previously only engine-powered tools could go. It is equipped with a LED light to illuminate the blade tip and oil level window, greatly enhancing work efficiency. The chain saw also features a tool-less blade micro-adjustment mechanism and non-slip soft grip handle.