Tuesday, May 4, 2021

New cordless electric lawn mower

My original solar lawn mower built in 2005

Back in 2005 I converted my neighbor's dead 22 inch Craftsman gas lawnmower to run on a 12 V electric motor using a deep cycle lead acid battery.  It has lasted 11 years and was crazy powerful.  I have had to replace the battery three times in the intervening years at a cost of about $80 per battery plus a $5 fee or recycling the old battery. Back then there were no cordless electric lawnmowers available and due to my commitment to reducing my carbon footprint, this was the only option I could come up with for mowing my lawn.  That mower was charged from solar panels on my shed roof.  You can read more about the construction of it on my blog here.  At 95 pounds, it is kind of a beast and in the peak of summer summer becomes tiring to push around for 20 minutes - fortunately the battery only lasts 20 minutes or so.

old vs new lawn mowers
Over the last several years, almost a dozen companies have introduced cordless electric lawnmowers and last year I started to review them.  The technology has come a long way!  What I find interesting is that there are two newcomers building cordless yard tools, Greenworks and EGO that are both very highly rated.  Cordless lawnmowers are also made by many of the established tool makers like Makita, Black & Decker, etc.  So this spring I did more research and winnowed my choices down to one of those two makes and settled on the Greenworks based on price ($400), size (20" cut width), performance and versatility.

There are several things that are unique about this cordless lawnmower:

  • It has slots for 2 batteries and switches from one to the other when one runs down. (It comes with a 4AH and 2AH batteries).
  • There are inexpensive secondary market batteries available for it with higher capacity than the manufacturer's batteries.
  • Run time with both batteries installed is estimated at about an hour.
  • It has 2 smaller sized blades rather than a single 20" blade.  
  • It weighs about 40 pounds which is much lighter than most gas mowers or my previous one which weighed about 95 pounds.  It is so light that it almost feels like a toy until it cuts through the heavy grass like a champ.
  • It increases its power/speed automatically when it hits heavy grass.
  • Cutting height is set with a single lever.
  • It can be configured either for mulching or a grass catcher on the back.
  • It is almost as quiet as my previous mower, and much quieter than a gas mower.  It has a very high-pitched whine from the dual motors that my neighbor thought sounded like a drone flying overhead until he came by to see it.

old vs new

I have already stripped the old mower for parts.  It turns out that the 3/4HP motor if purchased new today would cost more than the new mower.  So I've listed it on eBay in the hopes that I can sell it for at least half the current retail price.  That big honking gray motor weighs in at 31 pounds so it will be expensive to ship!

The new mower is still solar powered because all of my power comes from solar energy either from my solar panels or the solar farm that I subscribe to.  As Kermit the frog stays: "It's good to be green!"