We’ve been experimenting with electric propulsion for a while here at Curbside (see Jim Klein’s Tesla Model Y for instance). While I’m not ready to replace any of my vehicles with an EV just yet, when my old 21” mower broke an axle, I decided it was time to take the plunge into the world of battery-powered lawnmowers. Gasoline-powered lawn mowers spew out copious amounts of both noise and air pollution when going about their business – surely there must be a better way.
I had a surprising number of options to choose from: Battery-powered mowers have exploded in popularity in the past several years. Roughly a third of the mowers available at Home Depot are now battery-powered, at price points that largely match their gasoline-powered counterparts.
I chose a Ryobi based on my previous experience with their excellent power tools and on positive reviews on Home Depot’s website. I chose my specific model because it offered a 21” cut, variable-speed rear-wheel drive, dual blades (for a neater cut and better mulching), and a second battery, all for about $549 (on sale), which is about what you would expect to pay for a similarly specced Honda or Toro ICE mower.
The Ryobi is lighter than my old ICE mower, but not as much as I was expecting. Still, the lighter weight was appreciated, however, making the mower easier to handle and leaving fewer ruts in the damp sections of my yard. It is also significantly quieter, sounding very much like a large electric fan (which it essentially is).
The deck is made of plastic, and several reviewers observed the blade gouging into the deck as a result of the deck flexing. I haven’t observed that yet, and in any case, the deck is covered by a lifetime warranty, so I figured if the deck wasn’t up to the task, Ryobi would replace it.
Each of the massive 40V Lithium-Ion batteries stores 6 Amp-Hours of charge, good for a run time of about 30 minutes. While my back of the envelope math said I should be well in the clear (I can usually mow my entire yard in less than 45 minutes), I still experienced some “range anxiety” on my first mow.
While the marketing copy said that my mower was suitable for lots up to 3/4 acre, I’ve dealt with marketing types many times in my career and had my doubts. The copy was even caveated with disclaimers that indicated using the propulsion and dual-blade (both of which I planned on using) could shorten the run time of the batteries.
My lot is only a quarter acre (probably ~7000 square feet by the time you remove the footprint of the house and driveway) and is somewhat hilly, but still it should easily be within the stated capabilities of the mower. To make things easier, the grass was fairly short (having just been cut several days earlier) and dry. To save on battery life, I did not use the self-propulsion when going downhill, letting gravity do the work instead. As a last resort, I made contingency plans just in case I exhausted both batteries.
As it turns out, I needn’t have worried. After completing the job, both batteries were showing two bars (out of four) of charge, roughly a 50% charge.
The second cut would be more challenging. The grass was taller after going almost a week since the last mow. This was an early morning mow, so the grass was also a little damp from the morning dew. I was also going to mow a portion of the yard that I didn’t before, and that I cut maybe once a month, where the grass (and weeds) had grown particularly tall. And no glad-handling this time – I was going to treat it just like an ICE mower, using the self-propulsion 100% of the time. I was going to “drive it like I stole it!”
I ran the first battery in until it was exhausted – just over thirty minutes of run-time, with probably about 3/4 of the yard cut. I flipped over to the second battery, and after finishing up and mowing No Man’s Land, I was left with two bars on the second battery, which translated into maybe another 10 or 15 minutes of runtime remaining.
Being able to cut a 1/2 acre lot on a single charge of both batteries seems dubious (maybe by “hypermiling” using a single blade and a generous amount of pushing). The claim of being able to mow a yard up to 3/4 seems outright fantastical. Or is it? The included rapid charger will fully charge a dead battery in about 30 minutes, which just so happens to be the run time of a single battery. One could theoretically mow indefinitely by continuously swapping batteries between the charger and mower every thirty minutes or so.
While this may not be the beginning of the end of small engine-powered equipment (which I suspect will still be around for decades to come), it is definitely the end of the beginning as far as battery-powered equipment goes. Much like modern BEV’s, battery-electric mowers are essentially no-compromise devices, giving up nothing on their gasoline counterparts in terms of cost and capability.
The linchpin for widespread battery-powered equipment adoption has been battery life and cost (much like EV’s). We’re pretty much on parity now. Further cost reductions will inevitably make battery-powered mowers cheaper than their gasoline counterparts as the economic benefits of fewer parts (coupled with an associated reduction in assembly, warranty, and replacement part costs) are too compelling to ignore. The environmental benefits are simply icing on the cake.
The savings in my particular case are small but definite. Over a typical eight-month mowing season I’ll go through about a gallon of gas a month, which at $3.00 a gallon is $24 a year. Every spring, I dutifully spent $30 for a tune-up kit (air filter, spark plug, and oil change), none of which I need anymore. I also have no exposure to any repairs that I’ve had to make on previous mowers, such as replacing pull starters and drive belts. Assuming that I don’t have to replace a battery (a big if), I could potentially recoup my purchase cost in a decade.
But ultimately, the Ryobi isn’t about relatively minuscule cost savings so much as it is reducing my environmental impact and carbon footprint, and not coming into the house smelling like gasoline after mowing.