Real world experience Dewalt Flexvolt versus Milwaukee Fuel

[Robinson1]

According to Dewalt website the 60v Flexvolt circular saw averages 339 2x4 cuts per battery. According to Milwaukee the M18 Fuel 7 1/4" circular saw averages 750 2x4 cuts per battery. That's a huge difference and I personally can't see why there would be such a difference.

Has anyone used both of these saws on a jobsite environment? I know this site is highly in love with Milwaukee but I'd like some honest real world feedback.

Since I'm already in the Dewalt 20v system I thought the obvious choice was to go with the Flexvolt saw but after looking at some spec sheets I'm having second thoughts.

This would be for professional use doing general remodeling, and deck building. I don't do hardly any new construction and then it's usually additions.

I have two Dewalt 20v 6 1/2" saws currently and while they do the job they are showing their age. Also keep a corded saw in the job trailer but that's another discussion.

 

[GrantCee]

Likely a difference in battery capacity.

While they both have batteries listed as 12a/h capacity, the Flexvolt battery is probably only 12a/h at the (nominal) 20v; to get 60v from the same battery, they're likely switching from parallel to series cell connections internally to get the voltage up. That would cut the a/h rating down to that of the individual cell (or, more precisely, the individual cell package.)

That would mean Dewalt's 12a/h battery is actually closer to 4a/h at 60v, which would yield performance fairly close to the numbers you're seeing and explains the discrepancy.

 

[Rabid Badger]

Avoid Flexvolt like the plague, along with any other system that switches cells between a series configuration for discharge and parallel for charge. It just isn't a solution that lends itself to battery longevity.

That said, I'm not a huge fan of Milwaukee's "gigantic battery and utterly insane amperage" solution, either. It shifts the tendency for unreliability from the battery to the tool. Yes, they have a 5 year warranty but that doesn't keep you from losing money when it breaks.

 

[reader2580]

I got into Flexvolt only because I wanted a cordless air compressor. Dewalt was really the only one out there when I bought mine. No issues yet with the batteries.

 

[dnschmidt]

I'm a true red Milwaukee fanboy but Makita got this right. Their 2X 18 Volt tools are the bomb. They use 2 of their 5 A-hr 18V batteries in series and this makes the most engineering sense. Using 36V they can make their high powered tools using thinner gauge copper without losing any performance. I have their 36V track saw, leaf blower and Rear Handle circular saw and in my opinion each is the best in class. When the battery weighs more than the tool you're going in the wrong direction. I think Milwaukee is maxed out with the 12 A-hr battery. On a table saw who cares. On a 4 1/2" grinder they ****.

 

[rijndael]

FWIW: VCG Construction (on Youtube) has had an interesting high failure rate rate using the 60v battery in 20v tools. The tool just dies.

 

[mautotech]

I have the flexvolt circular saw and it is awesome. I can cut boards all day long and the battery only drops a line or two at the most. A couple of my contractor friends have borrowed it to check it and loved it enough that they bought their own.

 

[Handyandy23]

Avoid Flexvolt like the plague, along with any other system that switches cells between a series configuration for discharge and parallel for charge. It just isn't a solution that lends itself to battery longevity.

Is this based on actual failures or just speculation?

 

[Handyandy23]

According to Dewalt website the 60v Flexvolt circular saw averages 339 2x4 cuts per battery. According to Milwaukee the M18 Fuel 7 1/4" circular saw averages 750 2x4 cuts per battery. That's a huge difference and I personally can't see why there would be such a difference.

Has anyone used both of these saws on a jobsite environment? I know this site is highly in love with Milwaukee but I'd like some honest real world feedback.

Since I'm already in the Dewalt 20v system I thought the obvious choice was to go with the Flexvolt saw but after looking at some spec sheets I'm having second thoughts.

This would be for professional use doing general remodeling, and deck building. I don't do hardly any new construction and then it's usually additions.

I have two Dewalt 20v 6 1/2" saws currently and while they do the job they are showing their age. Also keep a corded saw in the job trailer but that's another discussion.

I agree with others that the difference is likely in amp hours. That said I think when you're getting up in the range of almost 400 cuts on a charge it starts to become a bit moot. That's a number I likely wouldn't ever get close to in a day. Plus it's a number where you easily have time to recharge one battery before the second one runs out. So with two batteries you basically get fully continuous runtime.

How do you like the performance of the 6 1/2" DeWalt? I'm torn between that and the 7 1/4" 20V version and having a hard time knowing the differences in power.

 

[Yarpo]

I agree with others that the difference is likely in amp hours. That said I think when you're getting up in the range of almost 400 cuts on a charge it starts to become a bit moot. That's a number I likely wouldn't ever get close to in a day. Plus it's a number where you easily have time to recharge one battery before the second one runs out. So with two batteries you basically get fully continuous runtime.

How do you like the performance of the 6 1/2" DeWalt? I'm torn between that and the 7 1/4" 20V version and having a hard time knowing the differences in power.

Seriously a cut every 30 seconds would be 120 cuts an hour, you could start at 7am and your battery would only be running out of juice come lunch time. Given you've gotta measure, mark and cut, I think 30 seconds per cut would be generous even as the cut guy. So you could plug in your battery to charge while you grab food or take a break, and be ready to roll after lunch to finish out the rest of the day. I can't comment on the merits of either saws actual run time however, but I'll be picking up Milwaukees simply because I'm already in their battery line. I'm curious too which AH batteries are listed in the tests

 

[Rabid Badger]

Is this based on actual failures or just speculation?

Based on numerous reports of Flexvolt battery failures that I'm not in the mood to track down and link and a healthy dose of actually knowing how batteries work.

 

[Rabid Badger]

FWIW: VCG Construction (on Youtube) has had an interesting high failure rate rate using the 60v battery in 20v tools. The tool just dies.

That makes a lot of sense. If the relay that switches between 60V and 20V gets stuck you're dumping 60V into a 20V system. They don't like that.

 

[Robinson1]

How do you like the performance of the 6 1/2" DeWalt? I'm torn between that and the 7 1/4" 20V version and having a hard time knowing the differences in power.

I have no complaints other than the blade size. 6 1/2" ***** for deck framing and the blades are expensive and hard to source without ordering.

When I first bought them I disliked the blade left configuration but after a couple weeks it was second nature.

I've heard people complain about poor line of sight on these saws but I've never noticed anything. I watch the blade when I cut and these saws are good enough to split the pencil line on a 16 foot rip if need be.

Runtime is pretty decent as long as you're cutting studs or 7/16 OSB. Cross cutting 5/4 decking is like a hot knife through butter. Long rips on treated 2x stock or cutting alot of 3/4" plywood drains a battery pretty fast

 

[techieman33]

First off, I think this comparison is all for naught. The Dewalt page that shows 339 cuts is a kit that comes with 6.0ah batteries. The listing for the bare tool and the 9.0ah battery kit don't say anything about cuts per charge. So I'm guessing that they're referring to using a 6.0ah battery.

https://www.dewalt.com/products/pow...4-in-184--mm-circular-saw-wbrake-kit/dcs575t2

Now the Milwaukee listing says 750 cuts using a 12.0ah battery. 750 divided by 2 is 375, which puts is pretty close to the 339 Dewalt is claiming for their saw with what I have to assume is a 6.0ah battery.

https://www.milwaukeetool.com/Products/Power-Tools/Woodworking/Circular-Saws/2732-21HD

That less than 10% difference is probably well with the margin for error for everyday use. I doubt anyone is going to hit either of those number other than under perfect conditions and super clean lumber. And as others have said, either way your going to have plenty of time to charge up the next battery before you have to swap.

Likely a difference in battery capacity.

While they both have batteries listed as 12a/h capacity, the Flexvolt battery is probably only 12a/h at the (nominal) 20v; to get 60v from the same battery, they're likely switching from parallel to series cell connections internally to get the voltage up. That would cut the a/h rating down to that of the individual cell (or, more precisely, the individual cell package.)

That would mean Dewalt's 12a/h battery is actually closer to 4a/h at 60v, which would yield performance fairly close to the numbers you're seeing and explains the discrepancy.

It doesn't work that way. The actual capacity of the batteries should be the same or very similar, depending on the brand of cells used. They should be able to deliver the same amount of watts, it's just going to be a matter of how efficient each tool is at using that power.

 

[American Locomotive]

60v at 4.0 Ah has the same energy capacity as 20v at 12 Ah. Ah can only be used to compare batteries of the same voltage. If comparing different voltages, you should use watt-hours instead.

As far as flexvolt goes, there is nothing inherently wrong with series-parallel switching. All modern batteries have balanced charging for each cell in the pack, so it doesn't matter how they're connected.

 

[Rabid Badger]

As far as flexvolt goes, there is nothing inherently wrong with series-parallel switching. All modern batteries have balanced charging for each cell in the pack, so it doesn't matter how they're connected.

Balanced charging, yes. Balanced discharging, not so much. When you take a bunch of cells in different states of charge and put them in parallel the cells with higher voltage will dump current as fast as they can into the cells with lower voltage. That's bad.

 

[Fcvapor05]

Balanced charging, yes. Balanced discharging, not so much. When you take a bunch of cells in different states of charge and put them in parallel the cells with higher voltage will dump current as fast as they can into the cells with lower voltage. That's bad.

You should call DeWalt, I'm sure no one there ever thought of that.

 

[WittHay]

I have a 9" Milwaukee Fuel grinder with the 12.0 battery and it works good with a long heavy grinder. Take that same battery and put it on a circular saw and i dont think it would be that user friendly

I also have a Makita 36V blower and SDS Max drill and as dnschmidt mentioned they are full featured and best in class.

For a 7 1/4 circular saw i bought a DeWalt Flexvolt. They come with a 9.0 battery and is balanced and light enough weight for my use. Comparable to the Makita corded saw which is the standard around here.

It not so much the amount of cuts but how many batteries do you want and how heavy are those batteries. Yellow is a nice saw that uses a fairly compact battery. The red has a garden tractor size battery strapped to the back of it. The teal brand uses a couple of lighter batteries but you need 4 to 6 batteries for all day use