Fresh off the boat - a truly new innovation in lawn mower design.
It arrived late yesterday and I noticed that the date code is 12/14/12, which means that it was built scarcely a month ago, and was fresh off the boat from China when I placed my order 5 days ago. It shipped from the west coast (Portland, OR), so it may have arrived by boat in a container ship.
It is supplied with two batteries that fit into two separate compartments on the mower. It only draws power from one battery at a time, starting with the battery in the left compartment, and then switching to the battery in the right compartment when it is depleted. One battery is a small 73 Wh unit, while the other is a large double sized 146 Wh unit. Since the two compartments will both accommodate the large size battery, it should be possible to increase the operating time by replacing the small battery with a second large battery. It will operate just fine with just one battery installed in either compartment.
A really unique innovation is the smart power sensing feature, which automatically varies the motor power and blade speed depending on conditions. When you first start the mower, the motors rev up to 5000 rpm full speed and then after a few seconds with no resistance they slow down and draw less battery power. Then as you begin to mow, they speed up again based on the resistance from the grass until reaching maximum rpms again under very heavy grass conditions.
The mower uses two separate motors with 10 in. cutting blades that counter-rotate and are offset. When the blades are both perpendicular to the cutting path, there is about 1 inch of overlap, such the the true effective cutting path is more like 19 inches than the 20 inches that is claimed by Greenworks. Also, the front wheels are 17 inch diameter, not 18 inches as claimed on their website. Fortunately, the claimed 3-3/8" (8.5 cm) maximum cutting height is spot on.
The rear wheels are located within the width of the deck, such that edging and cutting close to fences and walls is excellent. The handlebar is also narrow, permitting very good access to tight places. The large 10 inch rear wheels makes use in rough terrain a snap. The bag attaches and removes very easily, has a comfortable built-in handle on the rigid top section and a convenient bag-full indicator. It also has an inside liner on the right and rear sides to minimize dust blowing back at the operator when bagging in dry conditions. The rear stone guard is designed to rotate freely on the housing instead of flexing, so it's service life should be a lot better than guards that are bolted rigidly to the deck.
My only concern is availability of replacement blades, since they are totally non-standard and unique to this product. Also, the left and right blades are different parts. My past experience with Greenworks is that their support in this regard is very poor.
Right now there is no grass to cut, so I will have to wait at least a month before I can test it out and see how well it performs.