Bests & Worsts Reviews from Amazon

This is kinda a comparison of the 40v 21" push mower and the 80v 21" push mower. First, neither of these voltage ratings are correct. The "40v" model is 36v (10x 3.6v cells, or 20, half being in parallel with the other half in series) and the "80v" model is 72v. The marketers are able to lie about the voltage by using the word MAX, which looks cool since it has the letter X in it. Yes, it really is that stupid. 80 volts maximum is what the battery will read fully charged under no load, it is 72 volts since it's 20x 3.6v 18650 cells (or 40, since the two series sets are in parallel). On the sticker on the back of the battery it even says 288Wh (watt hours). Divide the watts (288) by the amps (4) and you get the actual volts (72). OK, so how does this 72 volt mower compare to the 36 volt mower? Favorably! Previously I had the "40v" model since It was available for a good deal and it seemed like the appropriate size/power rating for my small yard. That mower came with a 6.0 ah battery(!!) which means they packed in 3,000 mAh cells. I have only seen them use 2,500 mAh cells and 2,000 mAh cells so far in the "80v" batteries. Must be a cost thing. It is a lot of cells, we're talking about FORTY 18650s packed into the battery pack for this product. It's very unlikely that they're all tested and matched cells, so I am anticipating a battery failure in the near future. I have not had the pack apart but unlike Makita batteries, these have only four contacts, so it's unlikely that the charger has the brains or control to level out each of the cells... maybe the battery itself has some brains to perform this, but I'm not betting on it. OK so back to the mower. The "40v" would kinda bog down on wet or negligently tall grass. They both prefer to run at the slower speed and kick into "fast" when they encounter extra load on the motor. This is a handy power saving feature, but it would be great if it could be defeated so it runs at full speed all the time, it might help to reduce grass clumping due to slower blade speed. The "40v" mower had TWO safety features; there was an interlock key in the battery compartment that could be removed to make the mower not function, and there is a switch near one of the handle hinges so that when it's being stored upright, or with the handle folded, the mower cannot function. The "Pro" "80v" model does not have either safeguard. My guess is since it has "pro" in the name they're exempt from providing safety features. The $0.80 - 3.00 switch and wiring that prevents the mower from engaging while being transported with the battery seems like a cheapskate omission, especially since the "80v" model DOES NOT have a "dummy slot" to carry a battery that is inactive; this whole thing seems odd. If you've got numbskulls or children around, the "40v" model is intrinsically less prone to a lethal or nearly lethal accident. This 72v model could be potentially disastrous if transported with the battery installed. The "40v" batteries were equipped with a USB slot to act as a JUMBO power bank, and for some reason also had bluetooth. I never used that feature but I understand it's to let you see the power level from your phone... Thankfully the "80v" batteries do not have these questionably useful features. What I'm getting at is Greenworks has loaded in MORE functionality to their lower priced system. Hopefully the cost savings of not having these nonsense gimmicks has lended to them putting better quality cells in the batteries, but again I'm not about to bet on it. OK so back to the mower again. They (the 36v and 72v model) both use the exact same bagger, chute, mulch plug, blade. They have, like most other cordless mowers, the same stamped steel chassis with the easy to use height adjuster. I'd like it if they'd reduced the range of the height and instead provided greater granularity within a smaller range... I'll have to get out the file and make my own notches to have that. I don't know who would ever use the very lowest setting or the two (or even three) highest settings. Why do I have the "40v" and "80v" mower? I don't. I had the 36v mower but it was stolen, unfortunately. I decided to upgrade while re-buying my stolen equipment, and consolidate everything to a single battery system in the process. I think the ~ $100 premium for the 72v model is worth the price if for no other reason than it includes 50% more runtime on a single battery of the highest available capacity, saving us the cost of needing to purchase a second battery. Also the 2x voltage provides the mower with the torque necessary to not bog down. There were instances with the "40v" model where it would simply stall on very tall grass, even with a mostly charged battery. The "80v" has the extra bit of torque to behave like a real lawn mower in just about every realistic situation I've encountered so far. An annoyance: The thing is rickety. Between the lugs that hold the handle into one of three positions on the hinge, the control arm that bind the front and rear wheels for height adjustment, and the bearings in the wheels, this thing handles like a lumber wagon over all but the most perfectly smooth lawns. Old mowers from days gone by, with their independently adjusted and much more stout wheel height positioning mechanism and fixed-in-position handles, feel solid and are a much greater joy to use. For what it lacks in motor noise of a gas mower, it makes up for it in clanky boingity noises as it's moved across the lawn. Just grasping the handle and moving it slightly in each axis you will feel this this does not have a positive, solid feel, and I think that sucks. I was able to take some wiggle out of the hips by overdrilling the hole in a 1" fender washer so that it would fit onto the wheel axle, slightly pressing each of the rear wheels more inward so that the wave washer behind the wheel is actually engaged. The bearings in the wheels are very wobbly. People who are particular about things feeling sturdy might be turned off by this mower. In fact while I was at it I noticed that there was not a single screw/bolt on the mower that didn't benefit from at least a good 1/4 turn. Frustrating, especially for a "professional" lawn mower. The name really means absolutely nothing. And it's worth mentioning again that I would really prefer to have it run at full speed the whole time, or at least give me the option to chose the blade speed. This mower does NOT cut the lawn as nicely as even the cheapest, most basic fixed-height $150 lawn mower since it's not got the air movement necessary to lift and snip ALL the blades of grass in one go, even with a very finely sharpened blade.