Lawnmowing: manual and electric powered

[Tommy]

Caution: New Member with limited typing skills.

For my DIY electric lawn tractor project my first idea was to use friction drive reel mowers, but after testing
I found them to be unreliable except in ideal conditions(no trees). I'm now testing standard rotary electric
mowers(so far, so good).

http://www.youtube.com/watch?v=-9qfBXX8_Rg

Tommy

 

[dogman dan]

Cool. Just keep it away from your girlfreind. ( reference to the horror comedy, Frankenhooker)

 

[Tommy]

Just keep it away from your girlfreind. ( reference to the horror comedy, Frankenhooker)

for pure entertainment value the reel mowers wins, they do look cool slicing tall grass.

plowing snow can have an ominous look to it also.
http://www.youtube.com/watch?v=ylph_YJkCoc

Tommy

 

[swbluto]

Does anyone know if there's a diference in the motor between the lawn hog MM875 ($219) and MM1800 ($175)?

http://www.amazon.com/Black-Decker-MM875-Electric-Mulching/dp/B00005AKZI

http://www.amazon.com/Black-Decker-MM1800-18-Inch-Electric/dp/B002YK4V0E/ref=dp_ob_title_garden

I was mowing a customers overgrown lawn with the MM1800 (It was growing for 3 weeks and it was thick) and I had to do double passes with the MM1800 I owned, whereas I was able to cut it in a single pass with the gas lawn mower I own. So, I'm wondering if the MM875 is any powerful. I have my doubts since the motor has the same amp rating, but I'm hoping it might be wound differently in a more powerful way.

I'm really looking for a powerful electric lawn mower that can tackle "Almost All situations" (Except for the ridiculously long types), not just weekly maintenance types of lawns.

 

[veloman]

I've been using a Homelite corded 12amp mower. Homelite is a good name for it, it is not very powerful. It has trouble at 3mph through just 6 inches width of thick 8" tall Bermuda grass. It was embarrassing it took just as much time or longer than the reel mower I used last time on the same grass.

I started researching gas mowers. I wonder if the new models coming out are as polluting as I keep reading when I read about gas mower pollution. I know the old mowers are bad, but new standards have been in since '07. Does a new gas mower pollute the same as a modern car, time for time? I read that the old mowers 1 hour = 55 miles in a car.

I think reel mowers are great, for individual homeowners with small, clean lawns that they like to keep cut on a regular basis. They are just fun.

The lady I am cutting grass for still wants me to come, doesn't mind me plugging in..... surprisingly.

I too would like to know the most powerful electric mower out there, something to cut that thick tall stuff.

 

[dogman dan]

Here's the verdict on using the 24v cordless B&D trimmer for commercial use.

Here's what the innards look like on a killed one.

What failed was the bearing on the gear end of the little motor. I killed it by using it for about 3 hours more or less non stop, using 10s10 ah lipo to run all morning. Edit Oops, meant to say 5s lipo.

Cooked the cheap bearing in the motor, but the bearings on the head itself, on either side of the big gear are fine. So best to use this one for 30 min, then rest it awhile.

 

[auraslip]

Well... given that the stock battery should only last half an hour, it's easy to see the problem.

The blower is holding up good, but I never use it more than 5 minutes at a time.

Clearly, for a weed eater a conversion is required.

 

[dogman dan]

I kinda expected to smoke the brushes. Usually that's what you do to tools with a brushed motor. But now I know, drain two nicad batteries and put it away for the day.

It's still so much nicer to use than a heavy Sthil gas trimmer, that buying one each season is still worth it. But no more putting the lipo on it.

 

[Pure]

I don't think putting it away for the day is entirely necessary. Just after 30 or so minutes, put it down long enough for everything to cool down. I'd say no more than an 30 mins to an hour then pick it back up and go to work.

I've used my worx weed eater for commercial applications and it is still running today. I had 4 batteries for it. It got to rest between jobs wile in transit to the next lawn to be done.

 

[swbluto]

Here's the verdict on using the 24v cordless B&D trimmer for commercial use.

Here's what the innards look like on a killed one.

What failed was the bearing on the gear end of the little motor. I killed it by using it for about 3 hours more or less non stop, using 10s 10 ah lipo to run all morning.

Cooked the cheap bearing in the motor, but the bearings on the head itself, on either side of the big gear are fine. So best to use this one for 30 min, then rest it awhile.

Running at 40 volts on a 24-volt weed-eater might have also been a possible issue. :wink:

 

[dogman dan]

Not sure what I was thinking. I was running on 5s, But the thing has been run on 6s. Voltage was ok, but duration was not.

Yeah, you could just cool it off. But in summer, it could take quite a while to do that. Using the nicads that come with it, 30 min and you are done for the day.

 

[reagle]

It took a few years, but I finally got around to documenting my own mower project. It started as a bunch of separate posts here, and now has a home on my own blog: http://kuzyatech.com/upgrading-an-electric-lawn-mower-to-lithium-batteries

 

[reagle]

Not sure what I was thinking. I was running on 5s, But the thing has been run on 6s. Voltage was ok, but duration was not.

Yeah, you could just cool it off. But in summer, it could take quite a while to do that. Using the nicads that come with it, 30 min and you are done for the day.

Mine is still running original niCads it came with, but I do tend to let the pack run down completely in a few uses, and then charge it back up.

 

[veloman]

Lately I've been using a 36v lifepo4 pack on my lawn mower which is designed for 48v sla. The power consumption at 48v is about 500w just to spin. And 750w in thick grass. Guess what it is at 36v?

200w.

That's a HUGE difference, especially considering how it still cuts pretty well on 36v. It uses up to 450w through thick grass (doesn't cut well above that rate).

I cut my backyard tonight on about 120watt hours. Thick, lush grass, cutting about 4-5" off. About 500sq ft.

That is so efficient! This makes me think a human powered rotary mower is realistic. Reel mowers are more efficient but not good with weeds, debris, or tall grass.

This makes me wonder, how wasteful is a gas push mower? How much gasoline is burned per hour? My electric mower consumes about 350wh per hour.That's about 3% of the energy in a gallon of gas, right? (11kwh)

I watched a youtube recently of an electric ride on mower conversion. He was using about 5kw with the blades running. Holy crap!

I love efficiency!!!

 

[dogman dan]

3% of a gallon of gas, but a gallon will run a typical 3 hp gas mower for days, not an hour. An hours use is more like a cup of gas, or maybe even less.

But nevertheless, it's still a lot more efficient to do the job electric. And in an urban place, one hell of a lot less emissions. One hour mowing is like driving a modern car all day for dirty emissions. Not carbon, but the gunk. They need to ban the damn gas mowers, blowers, trimmers, unless they have a catalytic converter.

 

[veloman]

Oh yeah, I'm not sure why I forgot that part of the calculation. I think they use a bit more than 8oz per hour though.

But you are right, it's more about emissions. Also, maintance and never dealing with a mower that won't start. Price? Not much difference when buying new.

 

[dogman dan]

for the small, homeowner size mowers with 3.5 hp engines, about a quart and a half of gas will run it an entire 8 hour shift. Two fills of the tank. Bigger mowers will of course use more, to mow more, plus carry the operator around. Three blade mowers like yazoos or husky's.

I'm definitely not going back to gas, yanking that cord, pushing around that heavy engine. Worst summer of my life I spent pushing around the heaviest non self propelled mower made in 110F heat, a 5hp snapper. My electric mower feels like I'm pushing around an empty baby buggy, it's so light. Ahhh, that's better. 8)

But in the early spring, when the grass is thin, I still use an old school reel push mower. I don't do the whole yard at once though, just 5 min or so a day, as part of the dog shit pickup chore. No charging for the push mower. Can't use it once we get rain and the grass goes nuts though. Gets too hard to push then.

 

[Evoforce]

My lady likes to mow the yard. But she didn't like the gas and oil fill-ups and the pull starting. Got a deal on a refurbished ($100) 24v Black and Decker with one year warranty. She has been enjoying it much more in the year an a half since getting it. Couldn't beat the price or the added ease of this mower. When the lead dies, this sled will be getting lithium! It has worked great for the quarter acre lot.

 

[dogman dan]

Lithium it this season! So much nicer to push with a 2 pound battery vs a 20 pounder. 7s 10 ah lipo is perfect for that mower.

 

[wineboyrider]

I have a greenworks 40v mower with a 40v 4ah battery and now the girlfriend bought a 40v trimmer with the same battery! I can now mow and trim my entire huge 1/2 acre yard anytime I want, because once one battery is empty I charge it and I have not run out of juice yet. No pulling of starters, smoke, no carburetors it's awesome

 

[dogman dan]

I got particularly sick of gas trimmers. Always shaking the carbs to pieces as you worked.

 

[wineboyrider]

Echo has a 48v lithium system of mowers and trimmers now and Greenworks has 72v versions! The days of gas powered lawn tools is coming to an end actually. Gas engines work great when they start, but they are finicky mothers. :?

 

[Evoforce]

It is good that more, and more, reliable lithium equipment is becoming available and that the public at large is getting exposed to it. This will lead to widespread use and acceptance.

 

[Joseph C.]

Echo has a 48v lithium system of mowers and trimmers now and Greenworks has 72v versions! The days of gas powered lawn tools is coming to an end actually. Gas engines work great when they start, but they are finicky mothers. :?

A lawnmower with a steel chassis is never a good idea. Get one with a plastic body and it will last forever (assuming it's not left exposed to sunlight when its not in use) and you'll also get more done per charge due to the lighter weight.

 

[wineboyrider]

For the record I have the smaller 19" greeenworks and it's a great mower. The 80v version is steel , but I bet it could cut as good or better than most huge gas powered versions.