Push Mowers, Battery Vs. gas

[plowhog]

I recommend Electric . . . with Cord.

8 years, still going, left outside most of the time.

You "hand truck" a heavy transformer around to power an electric lawnmower? Sorry, that's over the line for me.

 

[Phil Timmons]

You "hand truck" a heavy transformer around to power an electric lawnmower? Sorry, that's over the line for me.

It is a Single Phase to 3 Phase converter. The motor on the old mower deck is a 3-Phase industrial motor. All Rather Olde Skool.

It is a Face-Mount motor, held on the deck with Unistrut, and the mower blade just mounts on the motor shaft.

Most of the time the converter just sits in the garage near the Electric Panel. I had just rolled it out for the picture.

But the whole rig is about 10 years old now . . . (had to add up the kids' ages to figure that out) . . . so I guess I am getting older, too.

With about 100 feet of cord, it reaches to the corners of the yard.

Now days we would do the whole thing with a Variable Frequency Drive, as they can convert from DC or Single Phase into Variable Speed AC.

 

[Diggin It]

I was about 10 minutes short of heading out to HD to pick one up. I gave my Husqy gasser one last chance and it started so I could mow what needed mowin'.

Still hoping to get through this season before biting the battery.

 

[Grumpycat]

I think the companies that have started with a basic battery platform and stuck with it even while improving their battery technology will come out on top. The companies that are changing battery styles every two years, obsoleting out the old batteries even in some cases while the product is under warranty, and no way to factory adapt the new battery into the old equipment are going to be the losers.

I have watched one company that builds battery powered mowers go from a 24 to a 36 to a 48 to a 56 to a 82 volt battery system in the past 10-12 years, and everything except the 82 no longer offers factory batteries or chargers for their products.

Yes. Planned obsolescence banking on consumer ignorance believing higher voltage is in all ways superior to lower voltage.

There is an advantage in the motor but it is small. Big advantage in solid state motor control. Voltage
drop across a transistor increases with current. High voltage lower current results in less loss. This doesn’t apply to mosfet controllers as a conducting mosfet closely resembles a resistor. The mosfet advantage is the ability to parallel many to reduce the forward conduction resistance. A hexfet has many in parallel inside one package.

Disavantage to higher voltage is the need for more cells. Rechargable lithium chemistry cells are about 3.8V each. For an 82V battery one needs 20-22 cells. A 56v battery only needs 14-15.

I am satisfied with my EGo equipment which has not changed battery format or voltage since they started over 5 years ago. Recently added a 10Ah that appears to be physically same size as the 7.5Ah. In recent years they added a “fuel gauge” to the battery to estimate SOC. Most of my batteries predate test feature and only have the 10% warning indicator. Must place battery in the fast charger to estimate partial SOC.

 

[RalphVa]

I'm confused.

This is $828: ( RYOBI 40V HP Brushless 21 in. Battery Walk Behind Dual-Blade Self-Propelled Mower &String Trimmer - (3) Batteries/(2) Chargers-RY401150US-4X - The Home Depot )

This: ( RYOBI 40V HP Brushless 21 in. Cordless Battery Walk Behind Dual-Blade Self-Propelled Mower with (2) 6.0 Ah Batteries & Charger-RY401150US - The Home Depot ) and this: ( RYOBI 40V Brushless Cordless Battery Attachment Capable String Trimmer with 4.0 Ah Battery and Charger-RY40270VNM - The Home Depot ) add up to $728

Am I missing something? Aren't they the same items? If so, why are the separate items $100 less than the package?

There are mark downs on the separate items amounting to $70. That accounts for most of it.

I bought them separate because I bought the carbon fiber shafted grass whip. Later, I bought a 2aH battery for the grass whip to lighten the load of handling it. 2aH is what I have for the Kobalt 40v which was no where near as powerful (not brushless). Sold it.

 

[Grumpycat]

When comparing battery mowers they all claim “equivalent to gasoline power!” without listing HP or kW.

They further obfuscate the comparison with everyone using different voltages wishing you to believe the higher the voltage the better.

Can’t say the manufacturer’s amp-hour claims are accurate but for now we have to take them at face value. Voltage is only half the story. Amp-hours is the other half. To unify for comparison multiply voltage by amp-hours to get Watt-hours.

Dewalt’s mere 20V mower comes with two 10 Ah 20V batteries to use simultaneously. For 400 Wh total. This is the effective size of the gas tank.

The Ryobi above simultaneously holds two 40V 6.0 Ah batteries for 480 Wh.

Ego has models which include 7.5 Ah and 10 Ah batteries, all 56V, for 420 Wh and 560 Wh. They have made SP mowers in the past which could hold 2 batteries at once but I haven’t looked that close of late. Thought what I saw at Lowes only held 1. Mine only holds 1 and I have 7.5 Ah. Dewalt and Ryobi require 2 simultaneously to reach claimed spec.

The EGo zero-turn holds 6 but “only” comes with (4) 10 Ah batteries. A bargain at only $5k!

You would be splitting hairs to argue one brushless motor is more efficient than another so if one says 480 Wh is good for an hour and another says 400 Wh is good for an hour then it us likely the 480 Wh is cutting heavier grass.

 

[check]

I think the companies that have started with a basic battery platform and stuck with it even while improving their battery technology will come out on top. The companies that are changing battery styles every two years, obsoleting out the old batteries even in some cases while the product is under warranty, and no way to factory adapt the new battery into the old equipment are going to be the losers.

I have watched one company that builds battery powered mowers go from a 24 to a 36 to a 48 to a 56 to a 82 volt battery system in the past 10-12 years, and everything except the 82 no longer offers factory batteries or chargers for their products.

I am indeed worrying about that with respect to my Ryobi tools. Ryobi has now started making higher voltage tools, and I am wondering how long it will be before they trash the 18 V stuff.

 

[lman]

I am indeed worrying about that with respect to my Ryobi tools. Ryobi has now started making higher voltage tools, and I am wondering how long it will be before they trash the 18 V stuff.

Hey it's a disposable society. The Chinese want you to buy a new improved product.

 

[Diggin It]

They are torturing me and twisting my arm.

The HD card has been sending out a bunch of free financing offers. As soon as one expires, they send another one with slightly different terms. Last week was 6 months no interest on purchases over $150 and I was able to resist going after a 40V line trimmer. The one I got today is 18 months no interest on purchases over $499 which is might tempting for the mower at $549.


I need to talk myself out of it. I need to make the gassers get me through this season and hope they do some season end sales.

 

[Oaktree]

The only BIG advantage with an eMower pusher is ... It can be left out in the RAIN.

Why would you leave something electrical out in the rain? Especially with the higher voltages that mowers use.

I only use a push mower to get around the edges into places the rider won't go, so I'd consider a battery mower if it came time to replace the gas one I have. I could also see it being fine for someone with a city lot-sized lawn. If I had a good-sized lawn to mow with it, I'd probably stick with gas.
As others have noted, my biggest concern is replacement batteries down the line.