quote:

Originally posted by ensigmatic:
The two saws I use most are my Makita 10" sliding compound miter saw and this: Rockwell 4-1/2″ Compact Circular Saw

I have that type of saw in the brushless cordless DeWalt flavor. MAN! What a handy saw. Sorry for the slight derail. EDIT - Link

quote:

Originally posted by sig2392:
Just homeowner type jobs.

Need to add an attic stairs, cut some 2x4s down that sort of thing.

I am just wondering if the new battery saws can work as well or close to the old corded ones.

And what size of blade to get.

Since it isn’t commercial use, Point to ponder. I bring this up since I recently completed a swing/glider frame with cross cuts using a Japanese pull saw. No battery. No cord. Really fast. Enjoyed using it.

Also realized I suck at trying to rip with it. But I like skill building.

I've had a M18 Fuel 6 1/2 inch model for five years now. Model 2730-20. I used it to frame a property after a fire. I never wanted for battery or power. I don't think my corded Skil Wormdrive came out of the case once during the whole project. Corded circular saws are dead to me now.

I use a Festool circular track saw (TS55) and it takes the place of a table saw for me.
Festool is expensive, but you can buy a Makita track saw and rail (identical to the Festool rail, since patent expired); that will give you incredible accuracy, as long as you use a good blade with it, like a Tenryu.

quote:

Originally posted by Skins2881:

quote:

Originally posted by maladat:
....

The Dewalt cut slightly more (about 5%), but nowhere near three times.

I think we are talking past each other here. Let's skip brands and marketing. Earlier you mentioned watt hours. This is a measurement of work. Think of it as a gas tank, if you have a five gallon tank you can drive 100 miles, if you have a fifteen gallon tank you can drive 300 miles. So unless you are like me and have a half dozen 20v batteries laying around, having a tool that accepts 60v batteries and 20v batteries (nominal value) than you won't be able to use them for any serious projects, just a few cuts here and there. I've done the real world testing the 60v do ~ 3x the cutting as the 20v ones assuming you allow some time to cool between cuts. Otherwise 3 x 20v actually will give you more cuts because your not dealing with a hot battery as often.

In the end 120vac > 60vdc > 20vdc if measuring by watts. If measuring by convenience and limited work being done 20v > 60v> 120v. It all depends on how you're planning to use it. If I was farming a basement and using a circular instead of a chop, I'd opt for corded. In my case I have 6-7 20v and one 60v, so I could do with cordless and have time to allow batteries to cool then charge.

You seem to have a fundamental misunderstanding of how the DeWalt Flexvolt 20V/60V batteries work.

The DeWalt Flexvolt 20V/60V 12 amp-hour batteries do not have three times the power capacity as everybody else's 18/20V 12 amp-hour batteries, because at 60V they are not 12 amp-hour, they are are 4 amp-hour.

The DeWalt Flexvolt 20V/60V 12 amp-hour batteries have exactly the same watt-hour capacity, regardless of whether they are used at 20V or 60V, as everybody else's 18/20V 12 amp-hour batteries.

That's because they have an identical number of identical capacity cells inside.

Here is an article with illustrations:

https://toolguyd.com/dewalt-fl...tion%20will%20change.

Even Dewalt's own marketing materials say the 60V MAX tools with the 20V/60V 12 amp-hour batteries have 8 times the runtime of 20V MAX tools using DeWalt 20V MAX 1.5 amp-hour batteries, because regardless of the operating voltage, they have 8 times the power capacity as the 20V 1.5 amp-hour battery.

If the batteries worked the way you have been claiming, they would have 24 times the runtime. DeWalt would be DELIGHTED to claim that. They don't, because they can't, because that's not how batteries work.

https://www.dewalt.com/products/power-tools/flexvolt

The DeWalt Flexvolt 20V/60V 12 amp-hour batteries have fifteen 3.6V, 4 amp-hour 20700 lithium ion cells inside for a total power capacity of 15 x 3.6V x 4 Ah = 216 watt-hours. Everybody else's 18V/20V 12 amp-hour batteries ALSO have fifteen 3.6V, 4 amp-hour 20700 lithium ion cells inside for a total power capacity of 216 watt-hours.

If you can figure out how to wire 216 watt-hours worth of lithium ion cells into a 648 watt-hour battery, then congratulations. You have just solved the world's energy problems forever and if you file for a patent immediately, you will become the richest man on Earth.

At least, assuming big oil doesn't put out a hit on you for putting them all out of business overnight.

Ok, I must be completely confused here. 12Ah is not greater than 4Ah and 15 batteries do no contain more than five do?

Strange because at my work we have a bunch.of batteries that add up to 540v, if we use just a single battery or even a dozen of them, they will never add up to the watt hours needed to maintain the load. In the end, watts (measurement of energy, or work being done), the higher the better.

For example, I have 2Ah, 4Ah, and 12Ah batteries for my saw. Believe it or not, the 12Ah ones cut more wood than the 2Ah ones. Maybe electricity works different where I live.

quote:

Originally posted by sig2392:
Just homeowner type jobs.

Need to add an attic stairs, cut some 2x4s down that sort of thing.

I am just wondering if the new battery saws can work as well or close to the old corded ones.

And what size of blade to get.

Do you have any other saw?

I use a Dewalt 18v circle saw all the time at work. While most of my stuff is 20v the circular saw is still 18v. It's fine for 2x4's or really any 2x stuff. I've ripped 3/4" plywood many times but a little slower then a corded saw.

The newer ones I'm sure are better.

That said the other day I pulled out my old Porter Cable saw and it's night and day the power between the two. For convince I use the battery powered one over 90% of the time.

quote:

Originally posted by Skins2881:
Ok, I must be completely confused here. 12Ah is not greater than 4Ah and 15 batteries do no contain more than five do?

Read what I wrote and look at the links I posted.

I will lay it out for you again, as simple as it gets.

A DeWalt Flexvolt 20V/60V 12 amp-hour battery and a Milwaukee 18V 12 amp-hour battery both have fifteen, 3.6V, 4 amp-hour cells.

They are arranged in three sets of five cells in series.

Each set of five cells is effectively a single 18V (although DeWalt lies calls it 20V), 4 amp-hour battery.

In the Milwaukee battery, and in the DeWalt 20V/60V Flexvolt battery used with a 20V tool, the three sets of cells are paralleled. This results in a battery pack with 18V output and 12 amp-hour current capacity.

Used with a 60V tool, the DeWalt battery switches its internal circuitry to place its three sets of cells in series, resulting in a battery pack with 54V output and 4 amp-hour current capacity.

Used with a 60V tool, the DeWalt 20V/60V 12 amp-hour batteries DO NOT HAVE 12 AMP-HOUR CURRENT CAPACITY. THEY HAVE 4 AMP-HOUR CURRENT CAPACITY. THEY HAVE THE SAME WATT-HOUR POWER CAPACITY AS EVERYBODY ELSE'S 18V/20V 12 AMP-HOUR BATTERIES.

You guys are definitely talking past each other.

Skins, both battery packs have the same number of cells. Hence, they have the same available power. The Dewalt has more cells wired in series to produce 54 volt, while the Milwaukee has more cells in parallel to output 18 volts. Either way, there are 218 watts available.

Are you working from the assumption that a Milwaukee 12ah M18 battery must be 1/3 the size of the Dewalt 60v? When Dewalt Flexvolt says its battery is a 12ah battery, they mean at 18 volts. Therefore, it is a 4ah battery at 54v, but it has the same number of lithium cells as a Milwaukee 12ah M18 battery. They are just internally wired differently to output different voltages.

It’s a Dewalt marketing gimmick to put 12ah next to the 60. They should label it 20/60v 12/4ah.

I wish I had bought a cordless long before I finally did, 18v Fuel Milwaukee here. It doesn't replace a good corded saw for steady use but it's awesome for limited use or doing things like cutting rafter tails.

A small table saw, definitely. Mine is 30+ years old, and has an 8" blade. No push-thru thing ["miter gauge assembly"] , but it has a fence. I just finished another cool box made from wine crates.

quote:

You guys are definitely talking past each other.

Indeed.

My comment was that using standard battery packs the ones marked 20v/4Ah you can't do as much work as ones marked 60v/12Ah. So if you go cordless you'll need lots of batteries or some of the larger ones or you will run out of juice. It had nothing to do with the brands.

I am quite familiar with batteries and how they work. If you combine more batteries you can achieve higher voltages or Ah. The ones I work with put out 540v and measured in KW or MW

I give up here. Even when I left everything else out and said focus on the watts which is a measurement of actual work and used an analogy of a 5 gallon gas tank and a 15 gallon tank like the 5 or 15 battery packs. In every case the car/batteries with more capacity can go longer. Which means that for larger projects a corded tool will be better unless you have lots of batteries be it in a 5 or 15 battery configuration.

quote:

Originally posted by Skins2881:
My comment was that using standard battery packs the ones marked 20v/4Ah you can't do as much work as ones marked 60v/12Ah.

The comment that started it all:

quote:

Originally posted by Skins2881:
A 20v or 24v circular saw is pretty worthless. If you go cordless, get the 60v dewalt so you can make more than a handful of cuts.

The largest 20V/60V battery Dewalt makes is a 216 watt-hour battery. Other tool companies make 216 watt-hour 18V/20V only batteries.

A 216 watt-hour battery in a 60V tool and a 216 watt-hour battery in an 18V/20V tool will perform about the same number of cuts, with a small efficiency advantage going to the 60V tool because of lower current draw.

So how is the 60V tool the cat's pajamas and the 18V/20V tool "pretty worthless" and unable to "make more than a handful of cuts?"

quote:

Originally posted by Skins2881:
My comment was that using standard battery packs the ones marked 20v/4Ah you can't do as much work as ones marked 60v/12Ah.

The only problem is, there are 20V 12Ah batteries, and Dewalt's 20V/60V "12Ah" batteries are 12Ah AT 20V and only 4Ah at 60V, which you still don't seem to realize.

A 20V 12Ah battery and a 60V 4Ah battery will do about the same amount of work because inside, they are THE SAME BATTERY with the cells wired differently.

OK, so everybody agrees. Whatever circular saw brand you buy, get the big battery.

I think I'll keep my 6 volt products.... since the higher voltage ones are no better.

Yeah, that's it, save money!

quote:

Originally posted by maladat:

quote:

Originally posted by Skins2881:
My comment was that using standard battery packs the ones marked 20v/4Ah you can't do as much work as ones marked 60v/12Ah.

The comment that started it all:

quote:

Originally posted by Skins2881:
A 20v or 24v circular saw is pretty worthless. If you go cordless, get the 60v dewalt so you can make more than a handful of cuts.

The largest 20V/60V battery Dewalt makes is a 216 watt-hour battery. Other tool companies make 216 watt-hour 18V/20V only batteries.

A 216 watt-hour battery in a 60V tool and a 216 watt-hour battery in an 18V/20V tool will perform about the same number of cuts, with a small efficiency advantage going to the 60V tool because of lower current draw.

So how is the 60V tool the cat's pajamas and the 18V/20V tool "pretty worthless" and unable to "make more than a handful of cuts?"

quote:

Originally posted by Skins2881:
My comment was that using standard battery packs the ones marked 20v/4Ah you can't do as much work as ones marked 60v/12Ah.

The only problem is, there are 20V 12Ah batteries, and Dewalt's 20V/60V "12Ah" batteries are 12Ah AT 20V and only 4Ah at 60V, which you still don't seem to realize.

A 20V 12Ah battery and a 60V 4Ah battery will do about the same amount of work because inside, they are THE SAME BATTERY with the cells wired differently.

This is getting comical at this point.

Go in your garage pull out two batteries one that is a 20v, and one that is a 60v. If the 20v and 60v ones cut the same about of wood, I'll mail you $20. Why would they put 10 extra batteries in the battery pack if it served no purpose?

Also you posted links that state longer run time with larger battery packs.

I promise you 100% when you parallel batteries you get more work out of them. 15 batteries will in fact do more work than 5.

OIC, Dewalt Flexvolt uses the same shell, regardless of how many battery cells they install. So the 4X pack is 1/2 batteries and 1/2 filler, while the 6X is 3/4 batteries and 1/4 filler. The 8X is all battery.

You guys are arguing the same thing.

quote:

Originally posted by Skins2881:
Go in your garage pull out two batteries one that is a 20v, and one that is a 60v. If the 20v and 60v ones cut the same about of wood, I'll mail you $20. Why would they put 10 extra batteries in the battery pack if it served no purpose?

quote:

Originally posted by Skins2881:

I promise you 100% when you parallel batteries you get more work out of them. 15 batteries will in fact do more work than 5.

I think I just figured out where you're mixed up. You either don't understand the difference between series and parallel, or you don't understand how the cells in power tool batteries are actually wired, or both.

You think that the Dewalt FlexVolt 20V/60V batteries use all 15 cells in 60V mode and only 5 cells in 20V mode, don't you? And maybe that every available 18V or 20V battery only has 5 cells inside? COMPLETELY ignoring the fact that would mean Dewalt's batteries were three times the size of everyone else's (which they obviously aren't)? And that it would be idiotic of DeWalt to only use 1/3 of the cells in the battery when the battery is used with a 20V tool?

Taking the 12Ah battery as an example:

In 60V mode, all cells are in use and there are NO CELLS IN PARALLEL, all fifteen 3.6V, 4Ah cells are in series, producing 54V with 4Ah capacity.

Again, the 20V/60V 12Ah battery has fifteen **4Ah** cells inside it, NOT fifteen 12Ah cells.

In 20V mode, all cells are still in use and there are THREE PARALLEL SETS of FIVE CELLS IN SERIES. Each five cell series set is 18V with 4Ah capacity. By paralleling the three sets, you get 18V with 12Ah capacity.

Look at the pictures in my last post.

Other brands' 18V/20V 12 Ah batteries have fifteen cells inside, too! They're even the same 3.6V, 4Ah cells!

Not to mention, in an earlier post I linked a test that showed EXACTLY THE RESULT you seem to think is impossible, because you have fundamentally misunderstood how the batteries work.

From DeWalt's own promotional images:

A DeWalt FlexVolt battery in 20V mode:


A DeWalt FlexVolt battery in 60V mode:


Notice how in both cases, all the cells are in use? And how when one number gets bigger, the other one gets smaller?

The 60V mode DOES NOT INCREASE the power capacity. The 20V mode DOES NOT DECREASE the power capacity.

The images are a 6Ah FlexVolt battery. Correcting DeWalt'x marketing lie that lithium ion cells put out 4V (they actually put out 3.6V): 18V * 6Ah = 54V * 2Ah = 108 watt-hours.

This message has been edited. Last edited by: maladat,

No way no how for my use, would I buy a table saw, and not a circular saw, if I could only choose one for all purpose.

Admitted Milwaukee fan boy here but I LOVE my Milwaukee cordless tools, including an 18v fuel brushless circular saw. Since buying it ~6 years ago. I have used it quite a bit... thousands of cuts both boards and plywood. I can only remember pulling out my corded Circular saw 2 or three time in those 6 years.

They also make a cheaper/weaker line of cordless tools, ones that are not "fuel" or brushless, don't want those except for the lightest of home gamer use.

You can use all the bolding and capital letters you want. It's not going to change my mind. 12Ah is 3 times as many as 4Ah and will cut ~3x as many pieces of wood. So if you are using 20v @4Ah batteries you will not be as happy as 20v @12Ah. I am a Master Electrician and have studied electrical theory as well as work with batteries at my job.

My batteries are a little older but the math is still the same. 2Ah x 20v = 40Wh --- 6Ah x 20v = 120Wh. A watt is a measurement of power or work that is able to be done. I know the cells are actually 3.6 or 3.7v each, but I didn't feel like doing the math.



It's marked right on the back of the battery packs.





You can actually see a physical size difference between the two packs. They also weigh different, that is due to the number of cells contained within.




The other link you provided clearly shows in the picture 18-20V/12Ah battery packs if you put 20V/4Ah batteries in those same saws they cut approximately 1/3 less wood. Therefore you will need multiple battery packs for anything involving lots of cuts. I was not talking about the brand difference, I am referring to the physical battery size and power output.

This is my last reply to you.

+++++


OP, my apologies and back to my original point. If you buy a cordless and you have a couple of batteries from an existing set, you will need to add more and/or larger ones to your collection, so don't buy tool only, buy combo with batteries, and maybe a few extra batteries if you plan on doing any significant work. Personally I have 7 of the smaller packs and one larger one, varying in sizes of 2, 3, 4, and 6 so I can use it all day long and keep batteries cooling/charging the whole time.