G-MAX 40V 20-Inch Twin Force Mower

G-MAX 40V 20-Inch Twin Force Mower
40V Battery Charge Time
40V Twin Force In-Use
40V Twin Force In-Use
G-MAX 40V 20-Inch Twin Force Mower
40V Battery Charge Time
40V Twin Force In-Use
40V Twin Force In-Use


Dual-Blade 20 Inch Cordless Electric Lawn Mower – 25302


Model Number: G-MAX 40V 20-Inch Twin Force Mower
Categories: ,

The 40V 20-Inch Twin Force Electric Lawn Mower Features At-A-Glance

40 Volt G-MAX    20inch Cutting Deck    2-in-1    5 Cutting Heights Automatic battery switchover

What Model Options do I have for this tool?

Model 25302 : G-MAX 40V 20-Inch TwinForce Mower
What’s in the Box? G-MAX 40V 20-Inch Twin Force Mower : Rear Discharge Bag : Mulch Plug : Isolator Key :  4Ah Battery  : 2Ah Battery : Charger : Owner’s Manual

Features & Benefits

  • Powerful G-MAX 40V Li-Ion Systems delivers greater efficiency with up to 70 minutes of run time  with included: 40V Li-Ion 2Ah and 40V Li-Ion 4Ah battery along with compatible charger.
  • 20-Inch cutting deck offers a great balance of maneuverability and cutting capacity making it ideal for mid-sized areas
  • Innovative SMART CUT technology adjust for power or runtime based on the thickness of your grass
  • Dual blades offer better cut quality, superior mulching and bagging capabilities
  • Automatic battery switchover pulls power from the second battery once the first is depleted to eliminate downtime
  • 5 position single lever height adjuster allows for a cutting height range of 1-3/8″ to 3-3/8″
  • 2-in-1 feature offer versatile use with mulching and rear bagging capabilities
  • Air flow tab on rear bag indicates when the bag is full and needs to be emptied
  • Easy Fold System for storage or compact transportation
  • 10″ rear wheels and 7″ front wheels make it easy to maneuver through any range of terrain
  • Includes two 40V batteries and a charger, 2ah and 4ah battery
  • Use with (2) G-MAX 40V 4 AH Li-Ion battery for up to 90 minutes of runtime
  • Compatible Only with GreenWorks G-MAX 40V Battery Models 29462, 29472 and Charger 29482
Product Includes
Twin Force Mower : G-MAX 40V 4Ah Battery : G-MAX 40V 2Ah Battery : Charger : Rear Discharge Bag : Mulch Plug : Owner's Manual
Safety Switch
Cutting Deck Width 
20 inches
Blade Length
Two(2)- 10 inch blades
Self Propelled Motor
Mulch Ready
Rear bag discharge
Wheels Sizes
10 inch rear : 7 inch front
Handle Material
Foam Padded
42.5 lbs
Weight with Battery
45.5 lbs
Compatible Battery
G-Max 40V 4Ah- Model: 29472 & G-Max 40V 2Ah - Model: 29462
Deck Material

User Manual (pdf)

Customer Support

To contact GreenWorks Customer Care, call our help line 1-888-90-WORKS (888.909.6757).

For 80V tool enquiries call our 80V PRO Customer Service Team 1-855-345-3934.

Our customer service teams will help you choose the right Greenworks product or help you with any issues you are having.

Rated 5 out of 5 by from Cuts great easy to use Took a shot on this mower and am very happy with it, makes a great cut and mulches nice. I had plenty of power to cut all my grass (about .25 of a acre), when it hit higher grass, it sensed that and sped up. It is not self propelled, but is pretty easy to push up a hill on my property. Plus it is pretty quiet. Am happy and surprised with the mower and would buy it again. Only used it twice so far, so can't speak of durability yet, but have seen it rated 4.3 out of 5 stars with 1500+ reviews elsewhere
Date published: 2016-06-15
Rated 4 out of 5 by from Actually works better than my old gas mower! I tried to do my homework before making the leap to a battery powered mower. I've only used this twice, but, the first time was tackling a lawn that was almost too high to mow. The batteries held out for my 1/3 acre with a little more to spare. I'll try posting another review at the end of the season. Very happy with the push button start. No more yanking on cords or flooded motors. Not sure yet about durability. Composite deck seems sturdy enough. Pretty quiet. Sounds like a noisy fan.
Date published: 2016-07-13
Rated 4 out of 5 by from Neighborhood Envy Despite conflicting reviews, I took a leap. I live in Northern Michigan and have a 1 acre lawn. I didn't want to deal with gasoline, oil, odor, and tedious maintenance that my neighbors (all of them) have to assume with their riding gas powered mowers. Sure, they cut down on time but I would bet anyone would trade an extra few hours of mowing for the hassle of gas powered outdoor equipment - plus, I'm not an individual who is customary with maintenance. I bought this mower three years ago to join the other members of the G-MAX family (I have the hedge trimmer, edge trimmer, chain saw, blower/vac, and snowblower [yeah, a battery powered snowblower in northern Michigan!]) Over those years, I have had several neighbors and strangers ask about the G-MAX family (mostly the mower) because they seem to be awed by it's lack of noise (comparatively) and odor relative to its performance! Because I have several of the other G-MAX family members, running out of battery power is not a concern - I simply swap the two depleted for two charged batteries and I'm good to go. I look at my lawn in terms how many AH it takes to mow. Depending on the pattern I use, I can finish mowing the lawn in 17-20 AH (about 4 hours). Ther is one particular area of my lawn where the grass blades are denser and thicker (where the drainage [septic] field is). The mower senses when I am in that area and boosts the power. It has no problem tackling the extra mulching. Only in that area might I see the mulched grass. Anywhere else, the grass is mulched so well, one would think the clippings were bagged. When I'm done, five minutes with a plastic putty knife to clean the underside and a wipe down (quick pass with the blower) of the deck and it's ready for the next week. I have bought and used hundreds of products online and have never once written a review - partially because I fell that reviews are typically not honest or written by those lacking a certain degree of common sense. Greenworks get my first review because I honestly look forward to using their products - even when it snows. With just some basic, logical maintenance and care, this family of products can last years (perhaps even decades) and will pay for itself several fold in just a couple of seasons. Even though I get some exercise pushing this lightweight mower, I am looking forward using the first ever battery powered riding mower!! Haha!!
Date published: 2016-06-29
Rated 3 out of 5 by from Beware... Bought this mower because the idea of not having to buy gas or oil again appealed to me. I read the few reviews posted on this site, most approved of the product. The mower is quiet, easy to push and store, starts every time but it has one problem. It does not have the power to lift (suction) grass so it can be cut in one pass. Repeated passes are needed to get an even cut. Also, if you want to "clean up" your lawn of few fallen leaves and small twigs, the lack of suction will not pick them up. Again, repeated passes are needed to achieve this. Only read one review that made reference to this. The extra time it takes to get the same results of a gas powered mower is the downside of this product. Figure on spending twice as long to cut your lawn.
Date published: 2016-07-09
Rated 3 out of 5 by from Ok I have had this mower for 2 years. I bought it because I did not want to store gasoline in my garage anymore and Greenworks seemed to have the most outdoor tools to work with one battery line. The mower definitely does not have the power to cut the grass evenly as other reviewers stated and requires multiple passes. This part stinks of course, but since I am not to picky about my lawn, I run one pass and don't mind it. I still think it is worth not having to deal with gas & oil. With the 2ah & 4ah batteries I get 45 min of mowing every time. The quietness is a great bonus too.
Date published: 2016-10-19
Rated 2 out of 5 by from Buyer Beware I've had one for over a year now, and the other reviews claiming that this mower does not cut grass evenly are correct. You'll see a lot of missed blades of grass with this thing. Also, while the warranty is nice, if anything goes wrong with it (like a wire going bad), you'll be waiting forever for a repair. GreenWorks' parts department is clueless. My mower went into the shop over a month ago, and he's still waiting on the right part to fix it.
Date published: 2016-09-03
Rated 5 out of 5 by from WOW I used a corded lawnmower for 15 yrs because the battery mowers were too heavy for this small female. This mower is a dream-come-true. Light-weight, effective on my longer grass (I don't mow too often for the health of my yard). The grass catcher is easy to put on and take off and collects leaves from my driveway, too. Good power and plenty of charge in the 2 batteries for my 110x110' lot with a small house not much garden. I've had the mower 3 months and all's well; I enjoy mowing again.
Date published: 2016-10-15
Rated 1 out of 5 by from Don't Waste Your Money!! Used twice. Leaves straggling long grass. After 20 minutes, batteries are DEAD!! Bought a gas powered mower to replace this thing!!
Date published: 2016-05-31
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G-MAX 40V 20-Inch Twin Force Mower, Two Batteries and Charger Included is rated 3.6 out of 5 by 10.
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I've had this mower for 3 1/2 years and still love it. The one thing I've recently noticed is that, on inspection, all wheels seem to have quite a lot of play in them between the wheels and the axles, although there is no wear anywhere to be found.

Asked by: Ward
Good afternoon Ward, The wheels on our twin force mowers are held on by simple cotter pins. Although unlikely it is possible that over time these pins have degraded allowing the wheel to shift a small amount on the axle. If you want to inspect the cotter pins each of the wheels has a small, removable, plastic hub which can be gently levered off using a small flatblade screwdriver. Once this has been removed the cotter pins should be exposed. The wheel sits on the axle and the cotter pin is slid through a hole in the axle and bent at one end to keep the wheel in place. If you find these pins are degraded simply slide the screwdriver into the looped end of the pin and slide it out (these pins are easily available at most hardware stores). Insert a replacement, remembering to bend it off to keep it secure and replace the wheel hub. This should prevent excess play between the wheels and the axles. For further help please feel free to contact our help desk (toll free) at 1-888-909-6757 and one of our agents will be happy to assist you. Hope this helps.
Answered by: Sam K
Date published: 2016-11-08

hi would like to know if you will ship to Australia

Asked by: macca 52
Hello macca 52, GreenWorkstools.com offers free shipping within the USA , UPS ground service Free shipping excludes Hawaii and Alaska.
Answered by: GreenWorks Team
Date published: 2016-11-07

Has anyone had this issue. Mower was working fine, charged the batteries and when I went to put them in the mower started by itself. The only way to turn it off was to pull the red key. Can't figure out what is going on.

Asked by: susanmly
Hi Susanmly I am sory to hear that you are experiencing issues with our unit. Please feel free to call our help desk (toll free) at 1-888-909-6757 and one of our agents will gladly help you out. All the best.
Answered by: Sam K
Date published: 2016-10-31

The red lights that indicate which battery is being used have stopped working and it now appears that the mower is using both batteries simultaneously. Fully charged 4ah and 2ah batteries both had two green lights when I stopped.

Asked by: pbensick
Hello pbensick, This is unusual. Please contact us at 1-888-909-6757 for further assistance.
Answered by: GreenWorks Team
Date published: 2016-10-12

What does the lock or unlock symbol on the mower blade mean? There appears to be arrows in both directions.

Asked by: Ronald
Hello Ronald, This is the direction to undo the nut/bolt to either loosen or tighten, as some are left handed thread.
Answered by: GreenWorks Team
Date published: 2016-10-07

I have the full line of G-max lawn products. Recently, one of the blades on the mower seems to hesitate or turns very slowly. What can I do to fix this? Thank you.

Asked by: ChristineL from NY
Hello ChristineL, If the mower has come into contact with hard surface this may have caused the shaft to jam, or there may be other issues. We do advise clearing your lawn of any debris. roots or rocks before mowing. Please contact us at 1-888-909-6757, we would like to look into this issue in further detail with you.
Answered by: GreenWorks Team
Date published: 2016-10-06

When I don't use the grass catcher, what do I do to get the grass to disperss out from underneath? If it's wet it binds the blades.

Asked by: Edwardeee3
Hello Edwardeee3, Ensure that the mulch plug is being used,when you are not using the bag, this will help with the excess clumping. After each use, we recommended wiping off the underside of the mower, this maintenance will help reduce the build up of grass mulch underneath your lawn and ensure a more efficient cut , as well as reducing the chances of the blade binding up in mulch residue. I hope this tips help. If you require more information please feel free to contact customer support at 1-888-909-6757.
Answered by: GreenWorks Team
Date published: 2016-10-06

Can I use two 4Ah Li-Ion batteries on this rather than the one 4Ah and one 2Ah?

Asked by: Derrick
Hello Derrick, This mower comes with a 4ah and 2ah. Yes, you can use two 4ah for this mower.
Answered by: GreenWorks Team
Date published: 2016-09-30
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