[mech987987]

If you want it to last longer than 20 minutes it would weight about 250 pounds.

Chainsaws are at the very corner of tools that have to be both portable, handheld, and very powerful. This means that their energy source should very dense. Lithium does not come close for the big saws.

Urban tree climbing arborists (that need a small saw to chop limbs while up in a tree) now sometimes use battery powered saws that run off of an "umbilical"- a cable off of the saw runs to a separate (backpack or other container) battery. These saws are among the smaller chainsaws (maybe a 12" bar, sized for chopping limbs). The other extreme is a saw for bucking and felling medium and large trees, which uses a MUCH more powerful motor and a 30" bar or bigger.