EGO has two 21-inch deck 56-volt lithium-ion cordless battery mowers that are quite popular and share a number of similarities: the LM2101 and the LM2102SP. The major differences between the two are that the LM2102SP is self-propelled has a larger-capacity 7.5Ah battery and it costs $100 more. For the purposes of this review we are going to focus on the features they share in common.
After sharpening both sides of the blade place it on the kits cone-shaped balancer. If one side dips below the other continue sharpening it until the blade rests level. Return the sharpened blades to the mower and reattach. If you have a torque wrench its a good idea to use it here. Often you need to tighten the blade mounting bolt/bolts to a specific tightness level. Typically measured in pound-feet your instruction manual should list these specs. For example my personal machine the Honda HRR216VKA between 36 to 43 lb-ft of torque is required.
Your Best Digs rated the Greenworks 22502 as the best electric lawn mower. The reviewer found this push mower easy to maneuver thanks to its lightweight design. He also liked that it was much quieter than the gas mowers he tested. However he noted that dumping the clipping was awkward since there was a crossbar in the way and he would have preferred it if the mower came with an extension cord. Greenworks offers the option of buying the mower with an extension cord for $30 extra.