Milwaukee Tool has shared new details about their upcoming M18 Fuel cordless mower.
News of the new Milwaukee cordless mower hit social media earlier this month, thanks to savvy shoppers spotting it in promotional signage, prompting Milwaukee to officially announce that they were indeed launching a new cordless mower. Here’s the original Milwaukee cordless mower teaser post.
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This is only a minor update, as the new Milwaukee cordless mower is still months away from launching. Still, an official image and details are definitely appreciated.
Milwaukee M18 Fuel Cordless Mower Features & Specs
We still have plenty of questions about the M18 Fuel mower, but here is what we do know so far:
- Part of the M18 cordless system
- 21″ steel deck
- Rear wheel self-propelled
- 3-in-1 grass management (mulch, bag, side discharge)
- Single point height adjustment
- Folding handles
- Upright storage
- LED lights
Milwaukee Cordless Mower Availability
Milwaukee Tool says that their new mower will be available for the 2022 season. In other words, it will probably start shipping in late Q1 or early Q2, 2022.
Questions?
Like you, we have plenty of questions about Milwaukee’s first cordless mower.
Is it powered by (1) M18 battery, or (2)? What’s the runtime like? Power? Will there be other models? I am sure that all this and more will be answered in a couple of months.
What questions do you have?
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Predictions?
Other brands have been launching larger and higher capacity 18V-class battery packs. Right now, Milwaukee’s highest capacity M18 cordless power tool battery pack has a 12Ah charge capacity rating.
Milwaukee could have launched a new mower much earlier than 2022, but perhaps they were waiting on the development of a higher capacity and longer runtime battery pack to power it with? Do you think that we’ll see a new battery launched alongside the M18 Fuel mower? Perhaps a new 15Ah HD or High Output battery?
Chris S
I could see this running off of two batteries doing separate tasks. (1) battery would run the blades and another battery could run the self propelled function (this could be useful for people who don’t really need the self propelled function all the time).
Just seems like to much of a load at 18V to run two different motors at the same time from (1) battery (let alone the weight and power draw required to push a steel 21″ deck).
There doesn’t appear to be any mowers at ~18V with a self propelled function or more than a 16″ cut.
Either Milwaukee is going to put the beefiest 18V motor ever on a lawn mower to drive this 21″ blade and drive motor, they are going to split the workload somehow (maybe like I mentioned), or they will double the voltage (I highly doubt this option mainly because Milwaukee has avoided it at all costs so far).
Jake
It’s a 36v platform. You’re going to see a bunch of 2 slot m18 things come out. Backpack blower (or higher output hand held), Chainsaw, a real lawn edger, etc… 2 m18s in series. It Shouldn’t be surprising to anyone since everyone else has a 36v platform.
Kingsley
I’d like to see 4x18V to make it less likely to stop on tall grass like my DeWalt does.
Brian A
My Makita too, and I hate the automatic high low power adjustments it makes. I don’t care about runtime, I want to be able to put it in full power all the time at my discretion. Also battery mowers are lighter and I have never cared about self propelled. Power, power power, all that matters.
Charles
exactly!
The self propelled bit worries me. I’ve never found a self propelled gas mower useful, I certainly don’t need an electric one.
That said I’ll buy this as soon as it comes out
Jayde Coyne
I agree
Wags
Self propelled is the only way to go.
Franco Calcagni
Just curious, what is your Dewalt? The now defunct 40v, the newer 20vx2, or Flexvolt…not even sure, is there a Flexvolt model?
Bryan Getchell
Why not use the mx fuel line?
Robbbbo
Probably too expensive for home owners is what I reckon. If this came out at a reasonable price with MX fuel battery and charger I would definitely get it. Bonus running on dual M18 batteries as I have plenty for home use.
Wags
The batteries are way too expensive for people who mow their own lawns.
TJ Cornish
4 12Ah batteries would make this a >$1000 push mower.
I think its well known that Milwaukee makes a lot of money on their battery packs. Are they going to be willing to sacrifice enough margin on batteries to make this product happen?
Right now it takes about 2 1/2 12Ah Milwaukee batteries to equal the runtime of the Ego 56v 10Ah battery. The Ego battery is $450. 2 1/2 Milwaukee 12.0 batteries is ~$600, not counting the three chargers you would need.
4 12Ah batteries would exceed the Ego runtime, but it seems silly to me to have to have 4 chargers and the annoyance of swapping in and out 4 batteries every time you mow.
MM
As I posted in the earlier topic about this mower I cannot see how it can compete power-wise with even a basic gas mower.
If this mower were equipped with 2x12ah batteries and if it were only 2.5 hp (half a basic gas model), it would run for 23 minutes.
Of course a less powerful motor could extend that runtime or runtime could be sacrificed to give power closer to that of a gas model, but I think it’s clear from the numbers that it’s going to disappoint on both fronts. If it’s as powerful as gas it runs for less than 12 minutes.
And while those numbers look pretty bad, keep in mind this is assuming 100% efficiency and assuming the batteries can keep up with that power demand without the overheating issues that occur with some of the higher power M18 tools.
MM
Whoops, correction: that’s not 23 minutes, it’s .23 hours. Less than 15 minutes run time for 2.5 hp, or 7.5 minutes for gas equivalent 5hp.
Dave
Milwaukee would in no way shape or form produce a mower this late in the game with that crappy of runtime. They are the pioneers at extracting the most amount of power out of 18V packs than anyone else.
Stuart
I agree – I’d trust they’d engineer the mower with user expectations in mind.
Sure, Milwaukee wants people to buy the mower, but they also want people to buy deeper into the M18 system of tools and cordless OPE. They wouldn’t put a disappointing “me too” product out there, there’s just too much at stake.
MM
I’d like to hear your take on the numbers, Stuart. Double check my math.
Stuart
In my opinion, the math is purely speculative.
The energy required to power a gas engine mower is not going to be directly relatable to the energy required to power a cordless brushless motor mower.
Consider light bulbs. You might have an incandescent light bulb pulling 60W to deliver 800 lumens. An LED bulb, on the other hand, might draw 9 watts to deliver 800 lumens.
Efficiency and energy consumption values cannot cross technological barriers, at least not without the burden of proof.
Brushless mowers also allow for smarter efficiency gains, similar to how modern gas engine vehicles can turn off at red lights or deactivate cylinders during flat parkway driving.
Until more details and information are made available, we can speculate but without high confidence.
Also consider that Milwaukee has Dewalt cordless mowers in their test lab. Dewalt’s earlier mowers disappointed when powered by 2x 5Ah batteries. Their newer mower does far better (Benjamen has been working with one to review).
I am positive that Milwaukee gave themselves a high bar to clear, and that’s why it has taken this long for a mower to come out.
I am also thinking that new battery tech can be involved here.
Your concerns about power and runtime are very valid, but there are simply too many unknowns right now to be confident about any power, efficiency, or runtime projections.
This is a very highly visible launch for them. Their goal will be to match and exceed competing claims.
Milwaukee has also proven quite capable at breaking assumptions and engineering around perceived limits.
I have learned that it is unwise to underestimate them.
If you really want me looking at numbers, let’s consider the EGO 21″ mower.
As an aside, one thing to keep in mind is that cordless mower deck sizing is often a little undersized compared to gas engine mowers. This seems to have become standard for the industry.
Okay, so Ego’s 21″ mower is said to deliver up to 45 minutes of runtime with a 5Ah battery. Their newer self-propelled mower is said to deliver up to 75 minutes on a 10Ah battery.
Some models report on grass cutting torque, but let’s ignore that for now.
Let’s assume Ego self-propelled mowers can get 38 minutes of runtime on a 5Ah battery.
That’s 38 minutes on a 280 watt-hour battery.
We need to treat M18 batteries as “20V Max” for apples to apples watt-hour comparison. This would be equivalent to a 14 amp-hour battery.
~7.37 watt-hours per minute of runtime would mean 2x12Ah batteries would deliver 480 watt-hours and ~65 minutes of runtime.
Milwaukee might be able to use a combination of efficiency optimizations to stretch that even longer.
We can look at other mowers’ runtime claims and try to derive prediction parameters for Milwaukee’s mower, but there’s also the possibility that they’ll break any such projections with a new battery launch or similar.
MM
@Stuart
“The energy required to power a gas engine mower is not going to be directly relatable to the energy required to power a cordless brushless motor mower.”
This is absolutely true. But note that I was not comparing the power put IN to the motor, in terms of the chemical energy in the gasoline. The HP specs of gas mowers are power outputs measured at the crankshaft. And likewise in the electric case I assumed 100% of the watt-hours in those batteries would go straight to power with no losses anywhere.
This has nothing to do with LED vs. Incandescent because the efficiencies of the various processes are already being taken into account. The gas rating is output, not input as in your light examples, and the electric mower is given the advantage of assuming 100% efficiency. For the “LED vs Incandescent” argument to hold any water here we’d have to be talking about fundamentally different cutting mechanisms, like comparing a typical mower to a reel or flail mower.
XRH07
if you ignore all the overheating and thermal timeouts that come with their cordless solutions, sure.
I’d wager they do a multibattery setup, but it’ll be one of those parallel setups that we’ve seen in a couple of Rigid products before. (Shop Vac and 7″ Angler Grinder iirc)
That way they can still claim they have an 18V mower that can “run” off one battery. But the only way to get a passable product will be by inserting 2 packs in parallel so the amp draw needed by the motor doesn’t quite cook the packs like in many other H.O.-class cordless solutions.
Yep, as I’m writing this I went back and looked at the Ridgid 7″ grinder and that’s exactly what they did.
“Ridgid says that their new 18V Octane grinder, R88040B, is the industry’s most powerful dual 18V battery grinder.”
Won’t be surprised if that’s the game Milwaukee/TTI plays with this mower.
philip s john
Yes. I agree. I am not impressed with Milwaukee HO and the 12 amph batteries.
It will most definitely have to be 2 x 18 set up.
All a red15 amph battery does is anger me on its waste when it would trip out from heat vs the yellow 60v performance at 9 12 and 15. Milwaukee is great but the HO tools get too hot… and loyalty to 18v sys was a huge mistake at larger tools.
MFC
Yes, so how they do it is they incorporate a torque sensor into the motor so that on frequently mowed lawns it uses an “eco” mode and in heavier grass it gives full power. This allows for it to last longer than 15 minutes unless it’s forced to run on high constantly.
The problem with a lot of Milwaukee’s M18 tools, that try to compete with higher voltage platforms, is the overheating. They’re able to get the power but the batteries can’t handle such a high rate of discharge and will shut down to protect themselves.
If Milwaukee is only going to use a single 12ah or 15ah battery for this mower then I see it either struggling in tall grass, or shutting off with any moderate use. With two 12ah batteries they should be able to get through a weekly maintained yard of about .5 of an acre.
They have to compete with DeWalt ($499 with 360-400 watt hours) and EGO ($549 with 420 watt hours) primarily and so they need to keep their mower at $599 or lower and around a 400 watt hour level.
philip s john
Yes. Finally. We need to say this more.
Milwaukee m18 at HO tools is a mistake.
2x 18 is fine. But they have many hp Tools triping out.
Charles
why is it a mistake? I have them. I use them as a contractor. And they work beautifully.
The only issue was the 9amps. And they replaced them without problem.
JET
IT’S MILWAUKEE THEY DON’T COMPETE WITH THEM, THEY COMPETE WITH MILWAUKEE…………… BUT YES 2 BATTERIES IN PARALLEL WOULD WORK TO KEEP THE M18 LINE WORKING.
Aj
First, electric HP often competes with gas HP at 2x or more the level. Elecrric motors can increase torque as they get biggest down, maintaining HP. Look at compressors, they might require 2HP electric or 5HP gas to run.
All these run time calculations also asume maximum continuous output. I bet 1HP is more realistic.
MM
You can’t cheat physics.
18 volts x 12 ah = 216 watt-hours per battery.
x2 batteries = 432 watt-hours total.
2.5 hp = 1850 watts.
432 watt-hours / 1850 watts = .23 hours = under 15 minutes.
That’s assuming 100% efficiency and ignoring heating. Real numbers will be worse because real life is not 100% efficient.
MM
Sorry, meant to reply to Dave above.
Jay
Totally agree with you Dave, Milwaukees not releasing a mower with 15 min run time, I’ll put my money on their engineers making a surprisingly capable 18v mower
Stuart
(When this happens, put a placeholder or other comment where you intended for a reply to go and I can usually move it easily.)
Albert
I think a simplistic and extreme assumption is being made that the mower needs a constant, continuous 1850 watts to do its job. I don’t think this assumption is true and that the load varies and is intermittent, even thought I don’t know what the values might be.
MM
I don’t know about you, but I run my mower as fast as I can until it bogs down and does not cut properly. Given that I think that power assumption is giving a huge advantage to the electric mower. And even if we give the electric a further advantage and assume it’s only 1 1/4 horsepower–which I think we all agree is ludicriously low–the runtime is under 30 minutes.
Of course different people’s needs may be different, which is why I did my comparison based on a gas mower. If you find a gas mower to be seriously overpowered such that you’re only using half of the power it makes then you’d probably love this mower. If you find a 5 hp gas mower to be inadequate, which I do, then you’d probably not find this mower of much value.
Mind you I hope I’m not coming off as a Milwaukee hater. I have many Milwaukee tools and I’ve been depending on them for years. But I think the choice of using such a small battery platform for something as power demanding as a lawnmower makes little sense as I think my math illustrates.
Maybe it takes four batteries? Maybe there are some new bigger packs on the way? Who knows. But I don’t think many will be happy if it’s two M18x12s.
Sean
People will be unhappy if they buy it expecting to get gas runtimes, but I don’t see why they would. Electric’s been out for long enough that everyone knows you’ll have to ‘refill’ more often.
By the same math, electric chainsaws, trimmers, etc. are all unviable as well, as is every other electric push mower out there – largest watt-hr I’ve seen is 560, most are half that, so Milwaukee’s 432 is not far out of the line.
I do expect to be disappointed, but because it’ll probably only be an ‘average’ higher-end electric mower, and possibly overheating problems. But the energy density is pretty much what anyone with a modern electric mower would expect.
MM
I think that some people will have very high expectations. If their cordless saw outperforms the corded model and their cordless trimmer outperforms or at least equals their old gas model, they’re quite likely going to expect similar performance from a mower.
You mentioned the same math makes other tools unviable as well. That’s not true at all. Most other tools don’t require anywhere near the power of a lawn mower. Most trimmers or small chainsaws would have a 1 or 2 HP gas engine, and they are only used intermittently. Cordless power can easily provide those numbers even on one battery. A lawn mower typically has a 5HP or more engine and it is run constantly. That’s a huge difference. And as for large chainsaws? They have the exact same problem as the lawnmower does: power requirement is too large for current ~18V batts. Nobody makes a cordless chainsaw that can take a 40, 50, 60″ bar the way a big gas saw can, not even close.
OldDominionDIYer
I don’t understand why you continue to try to compare the potential new Milwaukee mower to a gas mower??? There are lot’s of battery powered mowers out there with quantifiable watt-hours to deduce that the new Milwaukee unit can easily achieve the same available power as ones currently selling in the market. It’s ridiculous to continue to keep saying the same thing and not acknowledge that there are literally a hundred other battery powered mowers operating today on the watt-hours available from either a single 15Ah battery (which Milwaukee could easily build) or 2 12AH batteries currently available. They are not inventing something new here they are entering a market filled with various other models and Milwaukee brings to bare a tremendous amount of R&D the benefit of bringing current models from various MFRs to use as benchmarks. Tell me the last time Milwaukee messed up a major tool introduction? Their table saw is awesome, Their miter saws are great, there Packout system is the gold standard. I am confident their mower will be fine.
MM
The reason I compare it to a gas mower is because that’s a benchmark of power that I assume most people are familiar with so they can judge the expected performance of this mower versus what they are used to. I think that’s especially relevant since many people may want to replace their gas mower with an electric model to get rid of fueling hassles. If the motivation is to “replace gas” then how the mower performs vs. gas is very important.
You’re right that there are a lot of other electric mowers on the market, but the majority of them aren’t up to gas standards either. I’m sure Milwaukee has talented engineers and wants to make this a successful launch but no matter how talented Milwaukee’s engineers are they cannot cheat conservation of energy, and the energy in two M18 batteries isn’t much compared to the power requirements of a standard lawnmower. One potential implication of this is that bigger batteries might be coming out alongside?
OldDominionDIYer
My point is it doesn’t matter what your used to, there are only a quantified range of operating limits within the battery power lawn mower market and none compare to the gas mower market. So someone looking to convert from Gas to Battery is never going to find a comparable battery powered mower they will however have a plethora of battery powered units to choose from within a certain range. So my point is NO battery powered mower compares with a gas mower making your whole point mute. It would be like looking for a mid-sized pickup that equals the capacity of a full sized truck. While they essentially do the same thing they are indeed in different classes of level of performance. Most people never need nor use the capacity of a full size truck though some do and will continue to buy them but most can get by perfectly well with a mid sized truck and do. Just as many consumers can get by just fine with a battery operated mower will some cannot, and those that cannot just have to stick with gas powered, it’s really that simple.
MM
@ OldDominiionDIYer
“.So my point is NO battery powered mower compares with a gas mower”
I couldn’t agree more. But that doesn’t make my point moot, rather that *is* the entire point. I am only interested in an electric mower if it’s at least on par with my old gas model, and I imagine that may be true for many others too. That can be done with bigger batteries like the MX platform but it’s not going to happen with M18.
Of course there are many other electric mowers on the market. Most of them are no different than this one: drastically underpowered compared to gas. I didn’t mention them because this is a Milwaukee topic, so it was a bit silly to start talking about other brands.
Gordon
I seem to remember Milwaukee saying they had no interest in going to a M18x2 type of platform. Perhaps this changes their mind. But in the pretext of single battery, Milwaukee is looking at Ryobi 20v mower type of performance. Even with a new 15ah battery it’s not going to compete with anything higher.
OldDominionDIYer
@MM
While I admire your personal criteria for switching from gas powered to battery powered, I would suspect those are not the criteria most who switched used. Instead I submit that most were looking for capability to accomplish their lawn not an imaginary 1 acre lot that they don’t own. I know there are those that do use a push mower on a 1 acre lot but most would prefer a lawn tractor if they could I think, but either way not many will readily make the switch simply because the battery powered units currently available probably aren’t the best solution (nearly all are good for 1/2 an acre at most). I guess what I’m saying is the vast majority making the switch from gas to battery don’t have your set of criteria and those are the consumers the battery powered mower MFRs are aiming for not you. Folks like yourself will likely have to stick to gas powered for the near future. MX is a great system no doubt but those would probably out price the average home owner though I think it would be a viable setup for lawn care workers possibly. Whatever M18 arrangement Milwaukee introduces for their 21″ self propelled mower will be right in the mix of the top half of the current offerings and likely near the top. You can do all the math you want it’s irrelevant because there are already battery powered mowers that have over 45 minutes run time and can cut a 1/2 acre today so it is not undoable it just will not meet your lofty criteria. I get your frustration and agree with you that current battery powered mowers don’t equal current gas powered capability and doesn’t have to to meet the expectations of millions of homeowners that have small yards to mow.
Sean
A 1 horsepower string trimmer has the exact same underlying math as a 5 horsepower mower (as you said, you can’t cheat math/physics), and plenty of people use string trimmers exactly the same way they’d use a walking mower, full-out non-stop to cut their entire lawn – just watch any tool review on Youtube. I did this myself with my Quik-Lok trimmer until I got an 18v Ryobi push mower.
Sure, a few people might be disappointed it doesn’t have every advantage over a gas mower. But if you want to see how most might react to the real-world performance of this Milwaukee mower, you only have to look at user reviews at Home Depot or wherever of current electric push mowers – which, again, mostly have worse or similar power capacity as M18x12s would give. The proof is in the pudding, people are quite satisfied with the power and runtimes.
MM
The difference is that existing battery tech has sufficient capacity for a ~1HP tool, but it doesn’t for a much more powerful tool like a mower. 200-ish watt hours is plenty of power to run a 1 HP tool for a reasonable time. It’s not plenty to run a 5 HP tool for a reasonable time.
Charles
exactly. I don’t care if the m18 mower is as good as my 30hp Kubota…. I just want it to be as good as I need, which is small lawns.
My m18 blower isn’t as good as my stihl backpacks. My m18 trimmer isn’t as good as my stihl 250. My m18 chainsaw isn’t as good as my old Husqys
In fact, none of my m18 stuff is as strong as my stihl 2 cycle stuff.
And yet, we all use the M18 stuff over the stihl 95% of the time. Commercially. In the real world. Because it’s light, easier to deal with, and gets the job done.
Sean
The reason I point you to the reviews is to show that according to the people who use it 200/400/whichever watt hours does seem to be plenty. I don’t doubt your math, so clearly these mowers are not running at 5hp all the time, but it’s equally as clear that they have satisfactory power and runtime.
MM
“I don’t doubt your math, so clearly these mowers are not running at 5hp all the time,”
That is what I was trying to illustrate.
” but it’s equally as clear that they have satisfactory power and runtime.”
And that is something that each user will have to determine for themselves based on their use cases. For my yard, a 5HP self-propelled mower is already marginal, so the fact that this thing is not running at 5 HP all the time makes it clear that it is even more inadequate. Of course other people may find a 5HP–or perhaps an even weaker model–totally satisfactory.
Mopar4WD just posted below that they are happy with a 3.5 HP model so something like this would probably work fine for them. But again, that also illustrates different expectations. They mention “unless it is self propelled with a bagger”. In my opinion both self-propulsion and mulching capability–which uses much more power than bagging or side discharge–are must-have features for a push mower. I wouldn’t spend one second considering a mower which lacked self-propulsion or didn’t have the power to mulch.
Sean
I don’t have a problem with the statement that an electric mower will not be the equivalent of a gas mower in many aspects, I agree with that. My only point is that the consumer base is fully aware of what to expect out of an electric push mower, and that the statement:
“But I don’t think many will be happy if it’s two M18x12s.”
Is not particularly well supported by real world results. I am sure there are cases where wide-open 5hp is necessary to mow a lawn, but that does not appear to be very common.
philip s john
Its simple. Dewalt already did it. First gen 2 x20 for 40. At 5 amph. Alot of users were disappointed.
They could do the same with 2 – 5 6 8 or 12 amph batteries. But one 12 at 18 v will be garbage… over heat and trip out.
Sean
The reviews of the 2x20v’s seem fine? Maybe I’m not looking at the first-gen you’re talking about, I just searched ‘dewalt mower’ on Home Depot. Negative reviews are almost all quality control issues (randomly stopped working, pulley melting, that sort of thing).
Makita’s 2x20v offering seems well-liked too.
I myself own a low-end Ryobi 2x20v with 4ah batteries, it’s a brushed mower and the batteries are not even in series, they’re in ‘parallel’ (I don’t think they’re even used concurrently, it runs fine on just one). It’s not the most powerful thing, especially if I let my lawn go for more than a week, but it does the job without much fuss. I can only imagine how much better a brushless one from a higher-end company at double the voltage would do.
For the record, I do own a gas mower (a push one, also a riding one for the backyard). Yes, it’s more powerful. However, most of the time, I don’t need that power bad enough to bother filling up the carb again when I can just bust out the lightweight little Ryobi and knock out the front yard real quick.
It has also never overheated, aside from the couple of times I’ve plugged it in (it’s a hybrid). Overheating problems on 18/20v batteries are certainly real (I’ve overheated my M18 trimmer, both battery and tool, using it in more extreme conditions) but I don’t think it’s as common or inevitable as you might think.
Mopar4wd
After decades with 5-6.5 hp 21″ gas mowers last year someone gave me a not running 3.5 hp 22″ big box store cheap mower for free. Cleaned the carb and it fired right up. I have been shocked that the little mower with a bigger blade has no issue with tall grass in my yard even when it’s really overgrown. I can even throttle it down half way and it barley bogs down (much less HP). It’s one of the reason I think I can get away with a electric. Never really thought about it but My guess is 5HP is a bit overpowered unless it’s a self propelled with a bagger.
philip s john
One battery at 18v… even with a 15 amph battery will trip out.
That’s unacceptable.
ToolGuyDan
You can’t cheat physics, but your physics is wrong.
A 2.5-hp motor is producing 2.5hp at peak, but even at 100% efficiency, it only consumes 2.5hp of input power when it needs to apply its entire force to the output. Think of a car’s throttle pedal when going a certain speed downhill versus uphill on a steep grade.
With gas engines, there’s a baseline power demand (“idle”), and less efficiency outside of a narrow range of RPMs, which is why we have gearboxes. With electric, the only meaningful load is the load required to return the shaft to its target speed, which basically amounts to losses due to friction (bearings on the shaft, but more importantly, friction from e.g. a blade passing through a piece of grass).
Despite the saying, you absolutely *can* compare apples and oranges—they’re both fruit. In this case, they’re both motors, so considering energy input and output is reasonable. But because they’re using that energy so differently, you can’t make the conclusions you’re coming to by just writing down a few key stats and doing dimensional analysis on the resulting numbers.
MM
Nobody is talking about “input” power here. A gasoline motor which is rated for 5 HP (output) is consuming more than 5HP worth of gasoline and is wasting some of that energy as heat, noise, friction, and other sources of inefficiency. And likewise it takes more than 200 watt-hours of energy from the wall socket to charge a 200 watt-hour battery due to the inefficiencies of the charger and the battery chemistry. But we’re purely talking about *output* here. I specifically avoided any of that. The gas engine is rated at ~5HP *output* according to standardized testing. And I’m giving the hypothetical electric motor the benefit of assuming 100% efficiency, therefore it’s power output is exactly equal to whatever power is in the battery. I don’t think that is an unfair comparison, they are both power outputs, and I also went to far as to assume the electric was only half the power of that gas mower.
In the end, they aren’t using the energy any differently, they’re both spinning a vertical shaft with a rotating blade attached to it. If one of these were a reel or a flail mower while the other was rotary then we’d have an invalid comparison.
Robbbbo
No offence MM but its kind of sounding like a broken record. I understand your concerned and you have noted them multiple times but you cannot comment on something that is not available to comment on. If they make an excellent mower then you will have to eat your words 20 times. If you make the point once and they prove you wrong then its less embarrassing.
In my case I have read your calculations and agree that it is something that will be hard and as a consumer, based on that info, I will do my research before buying it to ensure it works as intended for my use.
Nathan
so the first flaw there is assuming your gas mower actually makes ____ HP.
The latest SAE J spec on industrial engine output shows they rate the new engines by torque out put at 3600 rpm. so that brigs and strattor 7.25 model engine on the toro/craftsman/husquvarna/ . . . . .. . mower is supposed to make 7.25 ft-lb of torque at 3600 rpm on some pump gas and I think they test them on 93.
Regardless what RPM do you think the mower spins up at? my husquvarna which would compete with this doesn’t even have a throttle lever. so hell I don’t know. I know it’s not running quite wide out – and I know I can fuddle with the carb and make it run faster. so is it 2500 rpm, 1900, 3950.
Now someone might notice there that yes torque measured at 3600 RPM happens to be where torque = HP. This is true, but once again what RPM does the motor run at when in use is what matters most.
Even if it does pull let’s say 6hp while mowing – does it mean then that it’s appling all 6 HP to mowing? Mine is AWD self propelled so some of that is turning the plastic gears that drive the wheels – sure. and that’s got loss too.
Meanwhile that electric direct drive motor has less loss and comparing motor watts doesn’t directly translate to a ICE HP output. And having 2 motors to run the mower with one taking on the self propel portion is a great idea. Let’s the blade spin consistently on whatever torque needed – while the traction motor is deailing with up hill or downhill etc.
MM
You raise reasonable concerns but I don’t think they mean much in the end.
First off there’s the question of “Does it really pull all X hp while mowing”. That’s obviously going to vary based on grass conditions. But when I think about it, I try and drive the mower as fast as possible without bogging it down or leaving a rough cut. So the power of the mower really is the limiting factor for me, I work it as hard as I can without straining the motor. I can feel the difference between a 5hp model and a 7.5hp model because the latter lets me go faster in tall or wet grass.
You’re also correct that there is no direct correlation between engine power rating and that of an electric motor.
But these reasons are why I assumed half power and did my math with 2.5 HP instead of 5 or more, I wanted to really give the electric mower the benefit here. I also did not account for any efficiency losses in the motor or gears or anywhere else. It is a best case scenario assuming a lightly loaded mower and 100% efficiency.
Splitting the batteries between drive and blade sounds like a neat idea, but it’s really not a benefit. There is only so much energy available in those two batteries to do work, just as how all the power in a gas mower runs off that single engine. Using one battery for drive and the other for the blade does not magically generate more energy out of nowere. What it does do is limit the power that either the drive or the blade could draw at any one time making such an arrangement worse. The drive consumes very little power compared to the blade so operating both batteries together makes a lot more sense because now the blade motor can split its power draw over two batteries. That also spreads the HEAT as well. Better to work two batteries moderatley than one battery hard and the other lightly. Putting the packs in series, if the electronics can handle it, would let the motor run at twice the voltage. That would improve the efficiency of the motor and would also reduce current draw and therefore heating of the packs. Series arrangement makes more sense. But in the end it’s still not magically generating energy where there was none before. There are still the same watt-hours present to be divided between power and runtime and nothing will change that.
ToolGuyDan
Splitting the batteries would be dumb. Nathan suggested splitting the motors, which is very smart.
MM
Totally agreed. Splitting the motors makes tons of sense, I completely agree.
But in the end it doesn’t matter for our theoretical discussion of power and runtime. In the end, all the power is coming from the same batteries and 100% efficiency is being assumed.
Albert M
The engine speed at which 1ft-lb of torque means 1hp of power output is actually 5252rpm, not 3600rpm.
The SAE J1940 power (in hp) is the torque (in ft-lb) at 3600rpm divided by ~1.5. Regardless of what number they put in the name, a Briggs 725 is a 4.75hp motor.
Kevin Bellamey
Actually, HP and Torque are equal at 5252 RPM’s and gas lawn mowers never get close to that. Probably about 1/2 that in use. The math for that is
HP= T x RPM / 5252 .
I read Milwaukees claims online and they claim that it develops more torque than a 300 CC Gas Mower. I believe it develops full power in about 1 second. They can do a bunch of power management tricks with microprocessors that are never going to happen on a gas mower. Also, gas mowers depend on blade weight for flywheel effect. That is unnecessary ( or desirable) on an electric mower. Other people refer to 20V packs of Dewalt (and other companies) and that is marketing ploy. Every current manufacturer uses Li Ion cells that are 3,6 V per cell. That number goes evenly into 18 five times, Dewalt and other companies used the “20V max” name because Milwaukee sued and won a lawsuit against a handful of tool companies because of their introduction of 18V Li Ion packs years ago! True story! Where does 56V come from? I believe it is really 54 V That would be a multiple of 15 cells x 3,6 V. Its normal to round up voltages when the result is a decimal like everyone’s 12V packs ( smaller platforms) that are actually only 10.8V. That is a pack with a multiple of 3 cells. I agree with other comments in this group that it will probably be a competitive mower, since they are so late to the game. Maintenance will be ZERO except blades and if you want you can turn it upside down with no oil / gas loss. No winterizing, or trips to gas station. No starting issues. Also, I’m not sure I care, but it has lighting. There are some advantages to electric mowers.
Kevin Bellamey
Sorry, fat finger Kevin meant 200cc! I should have read it before I sent it. Also, it was meant for everyone in this thread. I am challenged with these things
MT
I want to be optimistic about this, but I’m just very skeptical about an 18V mower being up to providing a good cut for anything but a smaller urban lawn, especially if it’s self-propelled and moving around a steel deck.
Champs
But if it’s a small urban lawn, like mine, then why do I even need self-propelled? The big slope out front deserves a better landscape solution than grass.
MT
Maybe you’re old. Maybe you have a disability. There could be lots of reasons someone with a small urban yard who isn’t you might need a self-propelled mower.
Big Richard
Self-propelled allows you to drink a beer whilst you mow. Maybe you are not a drinker, but personally it’s a feature I really appreciate.
Tom D
What if it has a built-in charger and when you’re done you plug it in in the garage? Sure you could take out the one or two large batteries but would you ever need to?
MM
That’s honestly a darn good idea.
philip s john
Good idea for budget ope… not top tier tool company that shares portable batteries among the hand tools and ope.
Charles
agree.
This would not be a feature to me. I already have 50 m18 batteries, and chargers lying everywhere
Gordon
Lets compare to the other battery mowers out there.
When tested, there was no significant difference in runtime of Makita’s self-propelled and non propelled mowers.
Makita claims they can cut 1/2 acre using 2 sets of 5.0ah batteries. That’s 360wh needed. Testing shows that is pretty accurate. Other tests used 6.0ah batteries and got 83min of runtime mowing. That’s 432wh total.
Dewalt 21in 20v X2 Claims 60min runtime or 1/2acre with 2, 10ah batteries. That’s 360wh. (they claim 400wh, but that’s not the right math)
Ryobi has a 20in, 40v that claims 42min run time on a 6.0ah. That’s 216wh and the reviews seem to support the notion that 42min is a little exaggerated.
The Ryobi 21in 40v with a 7.5ah claims it can cut 1/2 acre or 50min runtime. That’s 270wh.
Toro has a21in 60v, 7.5ah rated with 50min runtime , or 1/3 acre but that seems low. That’s 405wh.
Greenworks 21in 60v with 2, 4ah batteries claims over an hour runtime. That’s 432wh.
Snapper 21in 82v with 2, 2.0ah claims 90min of runtime. That’s only 288wh. (I know higher voltage is more efficient, but I have doubts about this runtime claim. )
Milwaukee 12ah battery has 216wh of power. You can see where I’m going with this.
Ryobi seems to be overestimating their runtime. The rest seem to be pretty close to accurate based on reviews, both professional testing and customer reviews. So Unless Milwaukee is planning on attacking that Ryobi market, they better have something amazing planned.
Using two batteries gets them in the mix with the Makita Dewalt, and the more professional brands like Toro. That is the only possible option for them. Unless they have been hiding the word’s first 20ah battery from us.
MT
As a short-term temporary owner of a 40V Ryobi mower, I can contribute a single data point of support for the idea Ryobi exaggerates runtime.
Adam
Do you think they are going to put higher amp cells in the same form factor as the 12ah, which makes more sense hearing the 15ah number, rather than another row of cells and have a 16ah battery?
But if it’s the former, that means they could increase the ah of the 8ah sized, and the compact for sure (already could be a 4ah released, which has a “certificate of compliance” for shipping a model 48-11-1845 M18 HO CP 4.0 )
Big Richard
If Milwaukee starts using the 5000mAh Samsung 50s cells that DeWalt and Metabo use, yes, they theoretically could produce a 15 cell 15Ah battery. They also could do a 10 cell 10Ah battery like DeWalt and Metabo currently offer.
Both DeWalt and Metabo say they have no plans to release a compact 5 cell 5Ah battery, probably because they just can’t get enough juice out of those cells with only a single set of cells. That could all change and I wouldn’t put it past Milwaukee to try it to say they are the first.
King duck
I’m still using a 3hp simplicity that the guy left at my house when I bought it so I’m not worried about the power definitely would be nice not dealing with gas but I think ego is going to get my money that 2 stage snowblower just looks to nice.
Robert
“(much, bag, side discharge)”
Pretty sure you mean mulch, not much.
Aren’t robot mowers the new hotness?
Stuart
Thanks, fixed!
Robot mowers are still very expensive. They’ve been around for a while – I first reported on one 11 years ago.
Aaron
Im pretty sure that Milwaukee told Belts and Boxes that there would be one version of this and one version only.
Randy
Since Milwaukee is so late to the game entering this tool segment, I would be curious as to what patent constraints exist. I am sure there are numerous and designing around them or coordinating with the patent holder can be a tedious and time consuming process.
Jayne Erin Defranco
I’ve never had a stinking gas mower always electric now no cords what’s not to like. The internal combustion engine had its time.
DAVID
I dunno, maybe I’m just a dinosaur, but as someone going strong with 15+ years on my B&S gas mower, I can’t help but wonder how long these will last in comparison. Times change and maybe the new norm/compromise will be convenience and cleanliness over longevity. I’ve burned a lot of gas and made a lot of pollution, but electricity generation isn’t usually clean and battery manufacturing and disposal isn’t either. Yep, I may just be a dinosaur.
J
According to our local Milwaukee Rep, It will be powered by a single 18v doing both tasks of cutting and the self propelled function. There will however be two slots available to load batteries into and it will deplete one and move on to the next one after. He said it would be standard shipped with 2 M18 12.0AH HO Batteries.
Aside from the hearsay from my local Rep, I have no further source to back any of this up however.
Big Richard
Makes sense to me, they “need” to keep it single battery to fit the M18 narrative, and having two additional slots in series allows them to triple the runtime. Three 12Ah batteries gives 648Wh total, plenty of juice to run a mower in terms of runtime (compared to competitors). Even using the new 15Ah FlexVolt batteries, my DeWalt would max out at 540Wh. At 18v, heat is always going to be their biggest issue because they are really pushing those packs.
I also wouldn’t be surprised if it was a dual blade to lessen the load on each blade, making it a bit more efficient.
If it is indeed kitted with two 12Ah batteries, it’s gotta be close to $800, if not more.
Big Richard
I may have misread this, I’m not sure if the rep meant there are two battery slots total, or two additional battery slots for spares. If it is the former obviously my numbers are too high and would total 432Wh. As J pointed out it is all hearsay anyways.
Gordon
That sounds completely reasonable. Milwaukee has made this bed already. They were adamant about never doing an 18v X2 or multivolt system. We knew they would never come out with a 36/40v system either. Dewalt ended their 40v ope stuff in favor of 2x20v. And look at how Makita’s XGT 40v is being received.
The big downside for Milwaukee is that they will fall short of their direct competition, Dewalt, Makita, and Ego, in power. And they’ll be astronomically more expensive than performance counterparts in Ryobi.
It’s a tight market space and they’re entering late in the game, without a blockbuster product. Sales will probably be decent with current M18 owners, and I’d bet they run some crazy good sales.
Charles
The self propelled on this seems completely pointless, but I guess they are reading how lazy americans are correctly. I hope the self propelled can be turned off.
If it can’t mulch that probably won’t work for me.
Otherwise, I can’t wait to buy one of these. I have 50 odd m18 batteries, and almost one of each of the m18 stuff. Barring gen 1 nailguns, and the 9amp batteries, it’s consistenly awesome.
I expect this to be awesome as well. They know what the competition is, and TTI has been building in in Ryobi for a while now.
I’ll buy it the minute it comes out. But from Home Depot, so I can return it easily if it’s awful.
I don’t care if it’s as powerful as my Honda. Or my big Kubota diesel. I care if it’s powerful enough to get the job done.
Grace
We’ve been wanting this to happen for a while now. I will be happy to see hubby buy this when it comes out next year. He already has plenty of batteries to run it. We have a tiny yard so it will be perfect.
Nothing but Heavy Duty!
philip s john
I have nothing but trouble with my 12 amph batteries. Overheating triping out.
One after 2 years is now not charging.
I have read about the 6amph may be better out of the HO batteries at heat and amp draw…. it should have more amps per cell. Obviously the 12 will have more run time with more cells… but is heat controlled per cell? If so this may be the issue.
Yes
Milwaukee needs to move to 4680 cells
Frosty
Is this actually happening? I have heard zero since August…..
Stuart
Yes. I expect to learn more after the New Year.
Frosty
Hey! Thanks so much for responding! Merry Christmas!! 🙂 – Frosty
MarylandUSA
The front and rear wheels appear to be the same size. If so, that probably means the wheels are eight in all around. That would be unfortunate for me, because I need 10-inch rear wheels to handle roots, holes, and bumps.
Big Richard
The rear wheels are larger than the front.
Big Richard
Little sneak peak of the new M18 mower.
Gordon
So 2, 12.0 HO batteries and a rapid charger definitely explains the price. But what’s still unclear is if the dual battery is only for increased runtime or if it actually runs at 36v ala Makita 18v X2.
Even so, it doesn’t seem competitively priced at $1k.
Big Richard
DeWalt’s new rear drive mower is available kitted with 2x12Ah FlexVolt batteries, and it is “only” $749. Makita gives you 4x5Ah for $699. It is nice that they include a dual rapid charger, like Makita. DeWalt only includes two compact/slow chargers (even though I am a proponent of slow charging whenever possible). Still $999 does seem a bit high when compared to others on the market, notably the other power tool brands.
As for the dual battery setup, they don’t say in the video but from what I’ve heard it does run at 36v. That’s why they stamped “dual battery” all over the box.
Franco Calcagni
Most of the last third of the video, “Now let’s watch it mow”, not impressive. It was mowing areas where the grass was so thin and not very high; you could barely see a cut line to follow. We’ll see when it hits the market. Being later than Dewalt and Makita, I am sure they learned a couple of things from them and the final product should be on par with them, more or less.
Frosty
Thanks for the update!
Doug Foley
Any news of a proposed battery operated push mower – not propelled?
Stuart
Not that I’ve heard about yet.