New 80 volt push mowers

[Warren]

The first "flight" of our 80 volt electric push mower is on hold. The fog has lifted, but skies are completely overcast, and the grass is still very wet. There appear to be two small windows in the ten day forecast. Stand by for live updates.

[Warren]

Sun came out, wind picked up. Put battery on charger, run through Kill-A-Watt meter. I had put it on the charger when it arrived, for a few minutes, so it was at 72.4 volts at the start today. Charger started at 80-90 watt readings, climbing to 343 watts in 45 seconds. Sat at that wattage for 29+ minutes, then started slowly tapering down. At 30 minutes it was at 170 Wh from the wall. At 58 minutes, pulling 20-30 watts (probably .25 amps at 84 volts out), it was at 230 Wh from the wall, and the charger went to idle, with no fan, at 0.0-0.9 watts. It did not restart after 12 minutes like that, so I pulled the pack off the charger. Voltage sat at 83.25 volts, 4.1625 volts/cell. When the wife gets back from the grocery store, grass should be just barely dry enough to mow.

[Warren]

Grass was tall and damp, ground still wet. Wife took about an hour, total run time, to cut it all. It really does have some sort of clever controller. The mower sounds to be running about half throttle most of the time. When it hits heavy stuff, it goes to full throttle. Makes perfect sense, if load is as veloman says, mostly beating air. Better to run at half speed until needed. Ended with two green LEDs, and 72.9 volts, 3.645 v/cell. The grass was taller, and wet this time. It took about 15 minutes longer, and .5 volts more than the cut we did with my neighbor's identical mower.

We put in 230 Wh from the wall. Figure 80-85% charger efficiency, that means it averaged less that 200 watts. I am guessing it pulls about 150 watts at cruise, and perhaps 450-500 watts at high load. I'd love to put a CA on it, at least temporarily.

[veloman]

That's pretty low, and good if it still cuts well at that wattage.
Sounds like there is some thought and engineering going into these mowers now.

What type of motor is it? brushed?

[Metallover]

Most (all?) of the new Greenworks mowers are brushless. There are a few other brands that have them too

Up to 60 minutes of run time with fully charged 4AH battery - battery not included
DigiPro brushless motors are more reliable and delivers gas equivalent performance
Smart-Cut Technology improves performance and extends run-time
21-inch steel deck with 3-in-1 design for mulch, side discharge or rear bag capability
Battery and charger sold separately, compatible battery and charger models GBA80200, GBA80400 and GCH8040

[Warren]

Yes. I was very skeptical, when my neighbor bought his. But it is really a well designed product. I wish they had had these when I bought my corded electric chainsaw. They have a nice 80 volt cordless now, and it would be great to make more use of the battery. My main concern now is that the company stays in business. Long term, that is important for getting proprietary parts. But at least it is only a lawnmower. I feel for those who bought a Think City, Vectrix, Brammo, CODA, etc., thinking they would have factory support.

[wineboyrider]

The vast majority of the watts goes into the blades spinning wind turbulence. I have an older 48v Craftsman which pulls 450w on a 13s battery. When I push it into moderate grass, the wattage only goes up to 550-600w.
It's still a lot quieter than a gas mower.
But If I run it on 33v, it is super super quiet, like barely audible from 20 ft away. The funny thing is that is still cuts fairly okay on the lower voltage if the grass isn't too tall.

I got a free gas mower today. 6.5hp Toro. Fixed it up and cut my back yard. Maybe the blades could be sharper, but it didn't cut as well. The stink and polluted air sucks to be breathing that in when you are working up a sweat. Tomorrow I will test it on some tall grass to see if it can handle the big stuff better than my electric.

The Greenworks mowers have a controller that amps up the wattage when it is in thicker grass. This allows them to be more efficient and the 40v and 80v lines are brushless.

[Warren]

The wife did her third electric mowing, the second with our mower, on Saturday. Charging it up for this mowing took 200 Wh, from the wall, per the Kill-A-watt meter, so this thing averaged about 170 watts while cutting. Amazing!

[veloman]

That's really low, wow. How tall was the grass?

[Warren]

It was 12 days since the last cutting. We had plenty of rain in between, so pretty tall.

[wineboyrider]

FWIW EGO has just introduce a self propelled cordless lawn mower.

[Warren]

The wife mowed again a week ago. Her new string trimmer arrived yesterday. Figured it would help get some use out of the battery and charger. The long range forecast calls for hot and dry, so we may not be doing much more cutting this year.

[veloman]

I bought a new 40v black & Decker string trimmer, without battery. My plan was to use my own 36v battery. But there appears to be two additional small wires that connect to the battery pack. Does anyone know what they are for? They must be critical for the unit to work because applying just 36v to the main contacts doesn't work. I thought maybe a temp sensor.... but I need to figure out how to bypass them. These batteries are expensive and I can't find any dead ones either.

[wineboyrider]

@Veloman they sense current as far as I know the greenworks batteries have the same two middle tabs.

[Warren]

Wife's mower, and weed whip still working great!

My neighbor has replaced his bicycle exercise program with his lawn mowing exercise program. He recently used the Greenworks, as a bush hog, to cut down the weeds around their pond, so doubled his mowing. He cuts for an hour, then electric weed wacks for an hour, while the mower battery recharges, four times a day, once a week. He says it is a better workout than his bike, and he doesn't have to deal with SUVs, and dogs.

[Warren]

The wife was feeling poorly the other day, and asked me to mow the lawn for her. It had gotten pretty long with light rain showers many afternoons preventing mowing. So this was a good test. We started with a cleared acre of lawn years ago. Wife converted about two thirds of that to wild flower field, so only one hilly, third acre left. I cut that long, damp grass, no problem, with one bar remaining. Makes cutting grass almost fun.

[spinningmagnets]

The thing I like the most about my cordless string trimmer is that...I have to trim and mow frequently in the summer, when the grass grows so fast. However...it gets brutally hot past 9:00 AM, so I have a conflict where I don't want to wake the neighbors who sleep late on the weekend, but...I want to do the yard work before it gets hot (for about four months a year). The electric works so quiet that I am not embarrassed to do yard work at 7:00 AM (after I have had my coffee).

I currently have the EGO 56V string trimmer (very happy with it), and plan to buy the 56V lawn mower next spring. I was disappointed at the earlier 18V products, and even the 28V / 36V products, but the higher volts are a clear winner.

[Metallover]

Looks like a new mower is out with a 5Ah battery and is self-propelled! $566 on Amazon.



https://www.amazon.com/GreenWorks-MO80L ... =80+vmower

[veloman]

Warren, would you be able to get the part number of the motor on your new mower? I want to see if I can buy just the motor from ordertree. I bought a couple 120v brushed motors but would prefer the 80v brushless. It's probably a long shot but worth a try. I just need the part number. Thanks!

After reading the reviews from the link posted on the first page, I have switched my interest from the 56v Ego to the 80v Greenworks. I'm thinking about buying the bare mower on amazon for 209. Do you think I could get my 80v ebike battery to work on it without any serious electronic trickery?

[Metallover]

Warren, would you be able to get the part number of the motor on your new mower? I want to see if I can buy just the motor from ordertree. I bought a couple 120v brushed motors but would prefer the 80v brushless. It's probably a long shot but worth a try. I just need the part number. Thanks!

After reading the reviews from the link posted on the first page, I have switched my interest from the 56v Ego to the 80v Greenworks. I'm thinking about buying the bare mower on amazon for 209. Do you think I could get my 80v ebike battery to work on it without any serious electronic trickery?

I can't figure if anyone's done that. If you could make a $300 GreenWorks battery with $100 of LiPo, you would have a killer system that's reasonably priced!

$209 is an awesome price! Someone here should scoop that up. Here is the amazon price tracker for the mower: http://camelcamelcamel.com/GreenWorks-G ... ext=browse

[Warren]

http://www.ordertree.com/greenworks/par ... =361011179

Here is the board that the battery plugs into. I think it is also the controller for the motor, as none is listed

http://www.ordertree.com/greenworks/par ... =362011179

You can see the mating portion on the BMS here.

viewtopic.php?f=2&t=82461

The only other electrical component listed, or shown on the exploded view, is the switch assembly up on the handlebars.

http://www.ordertree.com/greenworks/par ... =311071179

Here is the manual.

http://192.168.1.1:8181/http://www.gree ... _final.pdf

[Warren]

Kind of interesting that some folks want the mower, and plan to use their bike batteries, while others are buying the batteries to use on their bikes. Maybe Greenworks needs to start making e-bikes.

[veloman]

Good info, thanks.

it looks like someone bought the $209 Amazon deal for the bare tool. I just checked again and now it's 189, though back ordered a couple days supposedly. So i pulled the trigger and bought it at that price. I really want the automatic speed adjustment to maximize efficiency, but with a motor capable of decent power. I was just playing in my yard with a 120v greenworks motor running on 52v. It pulls 63watts just spinning and about 150w in easy grass. At 4amps it starts to stall, so clearly that won't work. But it just goes to show how efficient a mower can be in non-tall grass.

Hopefully I can get my ebike batteries to work. Otherwise I'll be looking for some used Greenworks ones.

[veloman]

How do you get the plastic casing off the mower motor/battery compartment? I found some screws on top but the bottom is firmly held.

[Warren]

veloman,

Did you check out the exploded view in the manual? Zooming in on it may give some clues. I haven't attempted to take mine apart. This guy is completely clueless about brushless motors, but he did manage to get his apart, at least twice.

https://www.youtube.com/watch?v=VzLYxOkILAk