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.
Your Best Digs also recommends the Sun Joe mower but the reviewer also added a number of caveats. He found it will get the job done if you prefer to only bag and just have $100 to spend. However the clippings compartment filled up quickly for him. And the height adjuster felt flimsy and required adjustments on each wheel.
Top 5 Lawn Mowers recommends the Sun Joe MJ401E to people with a small yard who dont want to spend a lot on a mower. The reviewer liked it overall for many of the same reason one might like any electric mower (no fossil fuels lightweight etc.) but he also noted that there were only three height positions with the lowest scraping the ground. And due to its 14-inch blade it takes longer to mow a lawn.