Recall for Greenworks and Kobalt twin-blade cordless mowers

[1 Lucky Texan]

1 Lucky Texan - Another possibility is this new G-MAX 40 volt model from Greenworks that would allow you to use your existing G-MAX 40 volt batteries:

https://www.amazon.com/GreenWorks-M...eywords=greenworks+g-max+40v+lawn+mower&psc=1

It is basically the same design as my 21" 60 volt model, except that it is instead 20" and has a dual battery port setup similar to the Twin Force. Amazon is currently selling the bare tool version for only $180.77 for a total of $195.68 including Texas sales tax. From what I can tell this new model replaces the 19" Digipro model that is no longer shown on the Greenworks website and is now being scalped by independent sellers for crazy high prices. It also appears that the 16" G-MAX model is being replaced with a new 17" model.

whoa - thanx for the link/info! - I have never seen that model.

 

[1 Lucky Texan]

that MO40L00 mower you linked also has ball-bearing wheels.

 

[MowerMike]

that MO40L00 mower you linked also has ball-bearing wheels.

On the negative side, I just found out that it only has one live battery port, and the second compartment is just storage for a spare battery. So, when the battery in the live port is discharged, you have to manually swap the batteries before continuing to mow. Kind of like my Twin Force is now. :laughing:

 

[1 Lucky Texan]

If only you had patented it! ha!

 

[MowerMike]

Amazon is selling the Twin Force today for just $259 in its Deals of the Day.

 

[MowerMike]

interesting - given any thought to some disassembly - if even to look for a broken wire or other obvious problem?

Well, guess what ? I opened it up and could not see anything obvious, so I ordered a new PCB under a cross-reference to the Craftsman version of this mower for $17.85 including shipping, which saved me about $10 over the Greenworks part. They are all made by Sun anyways, so there is no physical difference. The board is really complicated with no less than six separate unlabelled connectors. Two go to the battery compartments, two go to the motors, one goes to the start switch and one goes to the battery compartment status LEDs. I swapped them out one at a time to make sure that they were hooked up correctly, but really didn't know until I cut some grass that the motors weren't running backwards.

When I first tested the mower I got the same behavior as before, namely it would only start up with a battery in the right compartment. So, the problem was not the PCB ! I then opened it up again and poked around with the wires and connectors in the left battery compartment, but still no luck. I then jiggled the four connectors to the start switch, and this time the mower started normally with a battery in the left compartment ! So apparently the start switch has separate circuits for each battery compartment, and there was a bad connection for the left compartment, which triggered a fault signal with flashing LEDs and the PCB would not start the mower.

It is interesting how this thing works. There is a SPDT relay on the PCB which is de-energized when power is drawn from the battery in the left compartment, and energized when transferred to the right compartment. I could hear the relay click when starting the mower with a battery in the right compartment.

 

[1 Lucky Texan]

Well, guess what ? I opened it up and could not see anything obvious, so I ordered a new PCB under a cross-reference to the Craftsman version of this mower for $17.85 including shipping, which saved me about $10 over the Greenworks part. They are all made by Sun anyways, so there is no physical difference. The board is really complicated with no less than six separate unlabelled connectors. Two go to the battery compartments, two go to the motors, one goes to the start switch and one goes to the battery compartment status LEDs. I swapped them out one at a time to make sure that they were hooked up correctly, but really didn't know until I cut some grass that the motors weren't running backwards.

When I first tested the mower I got the same behavior as before, namely it would only start up with a battery in the right compartment. So, the problem was not the PCB ! I then opened it up again and poked around with the wires and connectors in the left battery compartment, but still no luck. I then jiggled the four connectors to the start switch, and this time the mower started normally with a battery in the left compartment ! So apparently the start switch has separate circuits for each battery compartment, and there was a bad connection for the left compartment, which triggered a fault signal with flashing LEDs and the PCB would not start the mower.

It is interesting how this thing works. There is a SPDT relay on the PCB which is de-energized when power is drawn from the battery in the left compartment, and energized when transferred to the right compartment. I could hear the relay click when starting the mower with a battery in the right compartment.

that is interesting - kinda old-school

was the switch issue related to the cable not pulling enough? I think some early failures were due to there being too much slack or a bent mount??? (I've' never opened mine up)

not buying another twin force, with all the plastic teeth missing, it leaves too many uncut stragglers at the high setting I use. It still runs fine. Indeed, if I get the single blade one you linked, I may cannibalize the twin force for a motor and battery mount and try to make a batt powered shop vac.

 

[MowerMike]

was the switch issue related to the cable not pulling enough? I think some early failures were due to there being too much slack or a bent mount??? (I've' never opened mine up).

I don't think it's a cable problem, but perhaps one of the internal switches not closing properly. When I jiggled the connectors, the switch terminals were very loose and moved a lot. It might be nothing more than burned or corroded contacts due to arcing. Anyway, if the problem reoccurs, I'll just replace the switch assembly.

 

[1 Lucky Texan]

ah - got it

 

[MowerMike]

Well, the problem with the mower not starting with a charged battery in the left compartment has come back, so I’ve ordered a new switch from Greenworks for $10 plus $8.99 standard shipping. No amount of connector jiggling will fix it, and it seems that one of the contacts is stuck in the closed position, such that it does not open when the bail lever is released. As soon as I receive and install the replacement switch, I’ll report back as to the result. I don’t use this mower very much anymore, since getting my new 56 and 60 volt mowers, so I’m pretty much done with sinking any more money into it.