I purchased a 56V 20" Ego brand push mower an trimmer with 2 batteries in 2014 (at Home Depot then, now sold at Lowes), and a EGO chainsaw 2-3 years later, so I have 3 56V batteries. All still running fine. Despite good reviews, I think the trimmer is terrible, the line feed just doesn't work for me. The mower and chainsaw are quite good. Full disclosure, also have a gas powered self propelled push mower also. I had two houses for about 1.5 years in 2015/16, had a self propelled gas mower at a house with a sloped yard and the ego mower at the house with the flat yard, both ~ 3/4 acre. Was finally able to sell one house after I moved, but kept both mowers.
90% of the time, I use the self propelled gas mower in sloped part of the yard, the electric in the flat part w/ trees, bushes, flower beds. The EGO mower is easier to push around trees, flower beds, though I could get by with onein either area. The EGO is quieter, lighter, easier to maneuver, the only one my wife will use. If I've waited too long to mow, or I'm not patient enough to let the grass dry completely, the batteries discharge relatively quickly, and I'm better off using the gas mower, but not to the point its a significant issue. If I am hauling my mower, its the lighter, easier to pick up EGO mower every time. The EGO mower can fold up the handle and stand upright in my garage. Easy blade sharpen/replacement. If my gas can is low, I just use the electric. Don't have to worry about draining gas in winter, changing oil.
Small combustion engines lack emission controls, NOx, CO, etc a relatively more important health risk, not immediately hazardous, so easy to ignore. Drive towards GHG reductions will continue to be a global trend. Both will drive customer perception and regulations. Little doubt, market share of electric lawn equipment will keep growing.
To me, the selection of gas mowers is still greater, there are many more inexpensive gas models, they are more widely available, will be that way for a couple more years, but not much more. The market for electric mowers has also become well served by Home Depot, Lowes, Walmart, Amazon, etc over the last 5 years or so. But, I'd think any seller would want to cover the growth area of the market, ie electric.
Batteries don't seem to be coming down much, I hope that changes as the supply chain gets built out, seems a few years away. Given the share of the overall mower cost, I expect if you need to replace a battery every 5-10 years, shoppers will be comparing that option to buying a new mower with new batteries each time.
