I gotta chime in here. You sound like you need to seriously open your mind and welcome yourself to the 21st Century. It's not 1945-75 anymore. Electric battery powered mowers are for now and they are real.
A few of my neighbors have battery powered electrics, and one has had his for almost a decade. One has replaced the battery. One has a rider that's electric (which I don't really like). The only maintenance I've seen is blade sharpening. No fuel, no draining gas, no oil adding or changing oil, no tune ups, no gas spoilage, no mechanic. Maybe that last one is the real problem here.
No, these things are not green cool aid. They work and they work well. No I wouldn't buy a electric yard tractor or zero turn, but mainly due to cost and lack of run time / battery capacity. If all you have is a 1/3 acre or less or a moderate sized suburbanite/urban yard, all you need is a 21 or 22 inch electric self propelled mower.
The manufacturers know it, even gas engine makers know it. Why do you think gas engine mowers ads talk about one pull starting, no oil changes and electric start options? Because they are trying to compete with electrics. The fact is that gas powered mowers are losing market share. Even Honda, who made some of the best small engine mowers has pulled the plug. Pun intended.
Did you really just suggest to an electrical engineer to join the 21st Century? I'd venture that I know more about the technology surrounding battery equipment than most here. I've had gas equipment, battery equipment (admittedly older equipment), riders, pushers, and even a reel mower. I've even considered robotic mowers. Spoiler alert... they're not ready yet either unless you have a yard with very specific limitations. Size, slope, number of obstacles, etc. I use whatever tool is best for the job. I think battery equipment is good for certain applications. Drills, sawzalls, impact wrenches, chainsaw maybe if you're usage is low. Batteries might be ok for trimmers & mowers too if you have a small yard. When I moved to my current property, the 48" ZTR that came with the property was taking me almost 2 hrs to do the mowing I needed. I upgraded to a commercial 54" ZTR. I'm down to a little over an hour for each mow now. I have an Echo PAS attachment system. Every mow, I also edge, trim, and blow. I use about a full tank every time. That full tank of gas is about equal to two of the large batteries on most battery trimmers, which cost more than my power head. There's NO way battery equipment would work for me. For the OP... he wanted a "forever mower". Battery mowers have not proven themselves to be worthy of the "forever" title yet. Yes, I believe they will get there, and in some cases, they can be very good solutions. If you never discharge the battery more than 50%, the battery will likely last a long time. If you never have a breakdown, you will also have a good experience. Right now, much of the battery equipment is proprietary. If you break something on that battery mower you bought at HD or Lowes... good luck getting it repaired. Most small engine shops don't work on battery equipment. An EGO battery will not work with any other mower. And an EGO battery for a riding mower will not work in an EGO trimmer. It's too big. Gasoline scales well. Fuel tanks can be various sizes, and they still use the same fuel. Gas mowers all use the same power source. A power source, by the way, that doesn't lock you into that company's battery ecosystem. The proprietary nature of battery equipment doesn't end at batteries, either. Often, the blade(s), blade adapters, spindles, etc are also proprietary. Reason being, battery packs don't have enough energy to run a blade used on a gas mower for as long as a gas mower will. They do tricks to make batteries last longer. Like drop the blade speed based on the load. Thin grass... slower blade speed. Mfrs might also decide not to support a poor selling model very long. I've heard of Kobalt mowers that were 2 yrs old that couldn't get parts. Lack of product support is not limited to battery equipment, but mfrs like Toro, Exmark, Gravely, Echo, Stihl, Husqvarna, etc tend to do better at this than, say, Kobalt. EGO, Greenworks, etc, I'm not quite sure where they fall on this spectrum. I think EGO is better than Greenworks, which is better than Kobalt.
I love technology. I have a drone. It's way cool. It levels itself, flies the direction I want it to, even in cross winds, by using an array of sensors. It feeds me a video image that is also leveled regardless of how fast or which way it's going. It can detect obstacles, and stop itself if it's going to hit something. It has some impressive technology. And it runs off batteries, which makes sense for that application.
Bottom line... use what works, but don't blow smoke up people's you-know-what to push an agenda.
