I got it with the 5ah battery , batteries on their own are very expensive . I’m waiting to see what Christmas deals are going to be out there to see if there is a good combo package for trimmer and weed whacker. That would give me an additional backup battery. I don’t think there is anything special about chain , standard Oregon should fit , same with bars .
One safety warning with electric chainsaws, protective chaps don’t work the same on them . They are very high torque and won’t stall like a gas unit.