We recently received a tough question, and it’s one I just don’t know the answer to. Which cordless reciprocating saw is best for real-world all-day demo work?
Dewalt FlexVolt? Milwaukee M18 Fuel? Hilti? Is there another cordless brand or saw that’s worth considering?
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L.K. wrote:
I am in real world 10 and 12 hour construction demolition. I needed a heavy duty cordless reciprocating saw that can last. Milwaukee M18 Fuel or Dewalt 60V FlexVolt? I went with the DeWalt 60V FlexVolt.
It was $400.00 for the tool kit, including (2) 60V FlexVolt batteries, charger and carrying bag. These heavy duty recip saws with heavy duty blades cutting through pipe, wood and nails last… 20-25 MINUTES ! We need something for A FULL day of demo.
My guys had (4) FULL sets of these saws! A DeWalt rep. confirms SHORT run times. You would need about (20) fully charged 60V FlexVolt batteries to make it through one shift of demo work! (It’s $ 180.00 for a set of batteries!)
Now the question is do we go Milwaukee M18 Fuel, or do we spend $1,200.00 and go with HILTI’s reciprocating saw – the 22V. Or the 36V?
There’s a lot we don’t know, but here is what we do. L.K.’s team has 4 full sets of FlexVolt reciprocating saws, and the runtime isn’t as long as they’d like.
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Is there something better out there?
Dewalt’s 9.0Ah batteries have hit the market, which will provide roughly 50% greater runtime, possibly a little more since they’re not an apples-to-apples bump up in capacity. The 9.0Ah battery packs have different battery cells – larger cells – and in theory so they’re capable of being run a little harder.
But that would mean going from say 25 minutes to around 38 minutes of runtime. A team of users would still need several sets of battery packs to go through charging and usage cycles each day.
Following is a quick intro to the Dewalt FlexVolt reciprocating saw. This was at last year’s Dewalt new tool media event, where they introduced the FlexVolt line to the world.
Here are some takeaways:
- More than 3x more powerful than the 18V/20V Max saw
- More power than their 13A corded saw
- Dewalt claims longer runtime compared to the Milwaukee M18 Fuel brushless circular saw
There’s a dilemma here. This is one powerful saw. Are you willing to trade power for runtime, if that was even an option?
In addition to the Dewalt FlexVolt and Milwaukee M18 Fuel options, I suppose the Makita 18V X2 model ($188 for bare tool via Amazon) is another potential option. Let’s pretend for a moment that the X2 saw can give you a little more runtime than the FlexVolt saw. It’s at least possible. But then you have 2 batteries to deal with, and 2 more to retrieve from chargers.
I don’t know enough about Hilti’s saws to comment on them, but I think the same problem would crop up – more power plus heavy duty cutting means faster drain on a battery pack.
My first instinct, other than to ask whether corded saws are an option, is to look at the reciprocating saw blades. How often are they changed out? Are the users working with dull blades?
Even with good blades, tough work will become tougher when the teeth wear down. I’ve seen some stubborn contractors who will work blades until the teeth are round wood-burning nubs.
When the time of cut goes from 30 seconds to 4 minutes, the workpiece has turned black, and the smell of burnt wood fills the air, it’s time to change blades.
Maybe changing blades more often will help, but that might add its own inconveniences, not to mention expenses. The benefits might not even be very noticeable or significant if the users try to be mindful of changing blades when needed.
Other than that, I have no clue what to suggest to someone who does more demo work in a day than I do in a year.
What would you recommend to someone who has been using a Dewalt FlexVolt reciprocating saw and returns to the charger every half hour?
The yeti
I got a Bosch . I’ve never used it on a job site where it was used all day long . Tends to be used for a cut here or there . I like it
Ed Misley
They need a corded tool for the bulk of the work and use the cordless for the edge cases.
Not every problem is a technology issue.
Q:Why won’t my Tesla drive non stop from NYC to LA?
A: because you are a virtue signaling dumbass using the wrong tool.
–Ed
Hang Fire
This.
Get a generator and extension cables if on-site power is an issue. Every contractor (every GOOD contractor) has a generator or 3. And as Ed says, you can still have your cordless, and you need line power anyway to recharge the cordless batteries.
Steven
What Mr Hang Fire said.
Your demands are very high for cordless. Even given new high cap batteries, there are clear disadvantages to cordless, I think this guy hit the limit.
jtr165
But Flexvolt is in no way an ‘endurance’ set of tools, also, right? You get either a 2.0 or 3.0ah battery to use with them. They’re very powerful for cordless tools, but run time is not something they’re able to promote as effectively.
But what about those batteries on the 20v line of recips? Is the needed extra power of the FV saw critical compared to the 20v max brushed or compact brushless model? I realize you then get into issues with blade feed rates, and the amount of time to make the cut with a weaker tool vs. a more powerful one…I’m no expert at demo work, but have a good amount of experience with various reciprocating saws (the landscaping company I worked for during summers in college was contracted to demo old barns right when the repurposed wood craze started to take off). That was early days of li-ion 18v tools, and most of them would be fine as far as power (runtime was a huge concern then, too, though)…the biggest question was whether we had enough fresh blades for the work, and corded tools struggled with worn out blades just as much as cordless.
but…I almost guarantee the 20v XR recip with a 9.0ah FV battery will run significantly longer than the FV saw…and assuming correct blades for the work, would still net more cuts between charges, even with some taking a little longer due to less tool output.
Overall, though, I agree. The needs for this guy are relatively far outside the capability of cordless tools right now.
Bremon
You’d be wrong. 162 watt hours is 162 watt hours whether it’s 54 volts at 3 amp hours or 18 volts at 9 amo hours. FlexVolt has a more powerful motor, meaning faster cuts, a brushless motor meaning more efficient use of the battery’s energy. The 20v Max brushed unit is a dog I wouldn’t recommend to anyone.
What I would recommend to the reader with the original question is a Milwaukee Super Sawzall or Makita AVT and an extension cord.
jtr165
It’s no where near that simple. That’s an armchair ‘tool A is 3x as powerful, so will have 3x less runtime, but do 3x as much work, as tool B with the same battery’
It simply doesn’t work out like that. If using an overly powerful tool for work that doesn’t require it, it’s fundamentally less efficient than using one balanced for it. No different than saying use a hammer drill in soft pine instead of a small compact, because the high powered hammer drill will bore x times faster…unnecessary if run time is at a premium, and the gain’s made by ‘faster cuts’ is completely offset by the draw of the device, and that the load on the ‘lesser’ tool is what it’s built for.
hence the question on needing more info on specific work. In my above example, we had access to plenty of those short lived 36v tools vs. higher capacity 18v options, with plenty of guys standing around saying what you’re saying. “its over twice as powerful, so you’ll get twice as much work done”. The powerful stuff was needed for 12×12 water-logged barn beams, but when running through dried out floor planks…guess which tools needed to be charged first?
lastly, I wasn’t specifically talking about that brushed saw. I own it, and yeah it eats batteries. There is a brushless version that has been praised for output and runtime, criticized for vibration. In either case, i’m only pointing out that it’s probably likely that high output cordless tools are being used in occasional situations where it’s not needed, and using the on paper math of what’s stored in a battery and how much work that translates into…is near sighted…
Bremon
I’m sure it’s easy to strike that “balance” on demo though, right? No? Quite a wide range of materials to be cut on demo, and if the 20v XR you’re talking about is the compact then that’s even more foolish a recommendation than the brushed unit. Lower strokes per minute and vibration to knock your teeth out of your head if you’re using it all day every day.
SharkyTM
I totally agree. I hear the same thing about cordless grinders… “I’m grinding 18″ pipe welds, and burning through batteries. Cordless tools are useless.”
Um, nope, you’re using the wrong tool. Cordless grinders and Sawzalls are for limited access/small/fast jobs, not 8-hour marathons. A generator and 200′ of 10/3 extension cord would be far more efficient and cheaper.
Richard l Dayton
Have good quality corded saws for when you are in one area and use the cordless when running around . And in my opinion if my guys were going to the charger to swap batteries twice an hour I would be happy they were getting the job done . So what if they lose a minute or so swapping a battery? Demo work is hard work and you can’t expect non stop cutting at the max rate for the entire day . Be a better boss
fred
It seems like you have lots of variables, too many unknown’s and too few equations to solve this problem. Ideally, you want to know is who has the cheapest (first cost and lifetime use) saw/battery/charger combination based on a per hour of your average use. Then you need t know if that saw is capable of your most demanding work. That assumes you know what your average and most demanding use is. You would also want to know what the longevity of the saw/battery/charger is likely to be – as it compares to others. If battery cost is the biggest hurdle, then you might look at who sells theirs in bulk for the best price. Switching to lower capacity – less pricey per amount of runtime – batteries might help with that cost – but will have an deleterious impact on productivity.
As Stuart says – too bad corded isn’t an option – then all that would impede continuous use would be how long it took for the saw to get too hot to hold onto.
When I ran a business – we used a demo subcontractor – who did all this hard work and clean up.
Good luck
Greg
Sounds like he isn’t the demo sub contractor.
The flex volt charge extremely fast as well. So if can get acces to power 3 batteries per saw would suffice. Honestly though maybe he needs a gas chainsaw ? That can run all day with no electric and cut as long as you have gas.
Greg
Sounds like he is the demo sub contractor.
The flex volt charge extremely fast as well. So if can get acces to power 3 batteries per saw would suffice. Honestly though maybe he needs a gas chainsaw ? That can run all day with no electric and cut as long as you have gas.
firefly
I don’t have much experience with Reciprocating saw but I can share you an experience that I had yesterday.
We needed to cut through about 20″ of 1/4 thick steel plate. I have the 20v compact recip saw DCS387B on a freshly charged 5ah battery. The blade is a brand new dewalt metal blade, 24 TPI. We ran out of juice before the cut was done.
Hang Fire
And if you didn’t run out of battery, you would have burned out the blade before the cut was done.
firefly
We did take multiple breaks in between. We also put an ice against the blade to provide cooling. This is not something that we do often so we just make do with what we have. I think I just need better blade.
Pete
You needed a carbide blade like diablos. I have no doubt that my cordless ryobi recip saw could cut 20″ of 1/4″ plate with the metal cutting carbide diablo blade. I had a project that required lots of cutting of 2″ tubing at 1/4 and it had no problems.
taras
Or another option would be a grinder with cutting wheels. The wheels are relatively cheap, and diamond grit or carbide grit wheels will last a while.
MichaelHammer
Good call. That is how to cut steel, you know, if you don’t have a torch.
firefly
You are right. I have never had the need to use a cut off grinder before. I have seen metal shop use them. But I have always thought the cut off wheels are fairly expensive. I just look them off and the pricing look to start about $3. http://www.homedepot.com/p/Diablo-4-1-2-in-x-0-040-in-x-7-8-in-Thin-Kerf-Metal-Cut-Off-Disc-DBD045040101F/202830995
I wonder how that fair against a good carbide blade on a reciprocal saw.
Pete
Having a background in welding/fabricating my go too tool is a grinder and it works great. But how am i to test a metal cutting blade if i dont cut metal?!
Honestly the grinder with a decent cut off wheel wins 95% of the time. The only time it doesnt is if you need a deep cut and cant rotate the object OR you dont want sparks. Such as- flammable work site, a heavy regulated jobsite that would require “fire watch”, damaging the area of painted materials etc.
firefly
Thanks Pete, I ordered a few from Amazon. I wanted to pick one up from my local HD but they were out of the exact blade that I wanted. The other HD have them so I’ll drop by them today if my wife doesn’t try to cut my head off for going to HD twice on a row :)))
Nathan
not to mention did you need to dress the cut when you were done. When I have to deal with steel I find whatever my use I sort of need to dress whatever I’ve cut. recip blades make some jagged cuts in steel.
hence why I’d use a grinder too
firefly
The cut was clean perhaps because I was using a 24 tpi. I will do another cut on the other side with a carbide blade 8 tpi and report back to see how that goes.
Lance
The Makita X2 with 5Ah or 6Ah batteries would have 11% or 33% more energy, respectively, than either DeWalt or Milwaukee solution. Makita has a dual port charger as well.
That would be an improvement, but not likely the solution to the problem. If generators and extension cords aren’t viable, looks like they’re stuck charging batteries multiple times a shift.
Pete
I agree with most all comments- battery is NOT the way to go for your problem. Even if you NEED cordless your gonna be burning those batteries up quick with that heavy use. At that point you might as well buy a more cost effective platform that has cheaper batteries- ryobi has cheap saw and their new HD 9ah batteries….. ya you get more run time on a brushless dewalt BUT when i can afford more batteries to keep my ryobi saw going all day is the dewalt better?
Id also suggest buying quality blades- diablo has carbide blades for metal and wood with nails.
A W
Not sure if it’s ok to reference parts on other blogs but the Pro Tool Reviews shootout shows Makita with the most watt hours available, followed by Milwaukee.
https://www.protoolreviews.com/buying-guides/best-cordless-reciprocating-saw-shootout/26835/
I would agree with going corded for this scenario.
Chance
Just reiterating what’s been said, but buy a nice quiet Honda generator, a few cords, and some nice orbital action saws and you will cut your frustration level down 90%, and productivity will be up 200%. Have a couple cordless saws ready for those few instances where a cord is not going to work.
Just because cordless tools are available doesn’t mean they are the best option for every job.
Dominic van lievenoogen
A far-fetched solution if they absolutely want cordless is the Makita 36v backpack battery for their garden tools. There is an adapter available that ends in 2 18v packs that you can put on the recipe saw.
That’s a 12amp 36v battery.
casey
did you all forget about chainsaws?
skfarmer
chainsaws don’t work very well in steel casey
they are also somewhat more dangerous, louder, and have exhaust fumes.
i would not want to demo in close proximity to a bunch of guys with chainsaws!
fred
Chainsaws do work well for concrete – but the ones that do are not exactly what the lumberjacks carry.
BonPacific
I’ve also heard of Firefighter chainsaws being used when demo-ing a roof. Specialized gear.
Anthony
I agree with pete. I don’t have much experience with kobalt, but their new 24v has slightly more punch than your average cordless recip saw and their batteries are cheap. REALLY cheap. A 2.0 amp battery is 20 bucks, their 1.5 amp is 10 bucks, their 4.0 amp is 40 or fifty. There are stronger saws and bigger batteries out there, but for the price, you could make a conga line of batteries to keep your guys working all day.
Koko the Talking Ape
All this brings up an interesting (to me) theoretical question, which is, why doesn’t the increased cutting speed of a more powerful motor compensate for the motor’s increased power consumption? Shouldn’t cutting a piece of board take the same amount of power regardless of whether it goes into a big motor or a small motor? (Let’s assume we keep the same blade and that it stays sharp, etc.) In the same way, pushing a big ball up a hill takes the same work whether you do it quickly or slowly.
(Gasoline engines don’t work the same way, partly because they have to idle. A more powerful gasoline engine will consume more fuel to travel the same distance and speed as a smaller one, because the more powerful engine is wasting a lot of fuel. But electric motors are different.)
Any thoughts, Stuart?
fred
While Stuart is puzzling over this – I’ll add a thought that feed rate may also come into play here. If the feed rate of a cutting blade is not optimum – more of the work is transferred to heat and less to actual cutting. On a table saw – one can see this phenomenon in part when you burn the wood along the cut line. A dull blade or gummed-up will also cause you to generate more heat. One of the classic observations in thermodynamics – made by Benjamin Thompson (Count Rumford) was that a when attempting to bore out a canon barrel with a dull tool he could produce enough heat to boil water. This was the basis for experiments on the mechanical equivalent of heat.
With a reciprocating saw – even in the hands of an experienced user – feed rate (pressure on the cutting edge of the blade and possibly saw speed setting) may not be perfectly optimized – and as the blade dulls more of the energy delivered from the battery will be turned to heat rather than useful work.
firefly
I think fred is right. The feed rate, speed of the blade, the geometry of the blade itself all become variable to determine how much of the work produced by the battery is going into the actual cutting and how much is wasted. So for a given blade and metal type there is probably an ideal speed and feed rate for it.
While I was cutting some metal with a reciprocal saw yesterday with a variable speed trigger I thought of the one key. If they have a variable speed saw with two mode. One is just a regular variable mode and another you can pick a speed profile for the material you are cutting and it will lock on to an ideal speed that would be neat… Obviously in my case a metal shop would just use a plasma cutter and be done with it.
Koko the Talking Ape
Fred and firefly, I think you are both right. You make me think about the exact action of cutting with a saw blade, and where the work is done.
It is funny. I know intuitively what “more power” means in a drill or driver. More torque means the driver can spin the bit against greater resistance.
But what does “more power” mean in a saw? I suppose it means that it can move the blade against more resistance. The resistance comes from friction of the sides of the blade against the material, but most of it comes from the saw teeth digging into and curling up a chip of the material. So more power means you can pull up a bigger chip, meaning you can push the blade deeper into the material. Meaning the saw cuts faster.
So again, why doesn’t the increased cutting speed compensate for the increased power draw from a bigger motor, making battery life about equal between two different motors?
Koko the Talking Ape
Heh. So it turns out I know just enough to confuse myself.
Assuming that cutting some piece of material takes X amount of work, regardless of how powerful the saw is:
Cutting that piece will draw the battery down the same amount, regardless of how powerful the saw is.
The difference is, the more powerful saw will do that job FASTER. So it will draw down that battery that same amount, but in less time.
So regarding Stuart’s question, “Are you willing to trade power for runtime, if that was even an option?” the trade-off isn’t really power for runtime. Of course we want more power, because it lets us work faster. The actual trade-off is between power and cost.
If a powerful saw drains a 6 A-h battery in 30 minutes, and it takes an hour to charge, then we only need three batteries (and two chargers) to keep that tool in continuous use, assuming we start with three fully charged batteries (actually we need only two fully charged batteries to start. The third charges fully in the time it takes the first two take to drain fully.)
So the real trade-off is really between speed and the cost of more batteries. Seen that way, it seems like buying a second and third battery would make economic sense. They will pay for themselves in greater productivity. The question is HOW quickly they pay for themselves. And that depends on how much faster the saw is, how much batteries cost, and how much each hour of work costs us.
Jeff
Honestly, the guy sounds a little delusional.
Either plug it in, or suck it up and buy enough batteries. Switch platforms all you want, it’s apples to apples. No one manufacturer has some secret proprietary technology that will make a battery last all day.
SS
i know hilti offers free demos for their 36V stuff (maybe the 22V, not sure), try before you buy. boom, solved.
the demands you’re talking are serious industrial-level stuff, it’s not likely you’re gonna find a $400 tool to do the work. and you’re not likely to get the same level of support from dewalt or milwaukee
glenn
Not sure if the question is a troll or not, but I will assume not.
To expect a high demand tool such as a grinder/recipro/circular saw/rotary hammer etc to run any more than @ 20-25 minutes continuously with the current battery technology, is in my mind an unreasonable expectation.
Buy tools that suit the purpose. We do A/C split installs, which doesn’t require continuous use or particularly heavy use of our tools, so we are using all cordless tools bar the vac pump.
Some tools we can get a few days on one battery, others we may go through 2 a day. However our tool use is light compared to other type of work. In saying that, we have around a dozen batteries fully charged ready for every days start and rarely use them all.
Demolition is high demand, high continual usage. A generator and mains powered tools as others have stated is the best bet and cordless for backup when its a quick job or in areas where you cant run a generator.
glenn
Forgot to ask. You must be plugging the 4 chargers in somewhere, so why not corded tools?
fred
We all probably do know that cordless is very convenient for many tasks – and particularly when we are working off of ladders, roofs or on staging – even when we can string an extension cord or air line for a pneumatic. That in part is probably why we have seen the explosion of new cordless tools coming forth from manufacturers compared to how few new corded tools they are releasing. LiIon battery developments and more brushless motors have helped fuel this expansion – but I also suspect selling batteries that do wear out and cordless tools that do get obsoleted – or at least become less desirable with age – is also more profitable for the manufactures. Hence their constant advertising – perhaps even hyping of ever increasing claims for their new cordless tools and larger capacity batteries. To be fair to LK (who started this post with a question for Stuart) – he like others may have been caught up in all of this hype.
My mantra was t try to use the right tool for the job. things like: don’t use a drill if a hammer-drill is needed, don’t use a hammer-drill when a rotohammer would be better, avoid the rotohammer if you need to roll out the Copco compressor and a jackhammer, don’t expect the jackhammer to replace a hoeram and finally know when to call in the rock drillers and blasters.
RX9
If you’re burning out full size batteries every 20 minutes, its probably time to move up to a more powerful cutting tool than an 18V class saw, or work with a more application specific device. Chainsaws and circular saws are more efficient and faster at cutting wood. Metal Circular saws and angle grinders work better on metal. Cut off tools work well on concrete and rebar. All of these can be had as battery powered tools, with voltages from 36-80V, but if you can handle the fumes, it may be time to work with a gas tool.
Corey
The only cordless tool that’s gonna offer that kind of run time you want is a work light lol The reason everything is marketed as x amount of cuts/holes/fasteners per charge, is because stating the approximate single hour-ish runtime any particular tool has even without load won’t sell tools lol. Get some 13 amp orbital recips and Diablo blades. Much cheaper than cutting edge cordless anything, plus better output. And if you’re hitting spots/material those are getting smoked on, then go get a grinder. Also a lot cheaper on the long run than all the batteries you would have burned up trying to run the entire project cordless.
JoeM
Forgive my bluntness, but… don’t we need higher quality recip blades, REGARDLESS of brand, for Demolition? I’ve had them included in sets before, and found they under perform compared to their Wood or Metal sibling blades. Take any line, from any brand, and whether they’re some sort of bi-metal, or titanium, or double-runtime family from any given brand… The Wood blades will cut Wood great, the Metal blades will cut Metal great, but their “Demolition” blades will do NEITHER very well at all.
At least in my own experience. Don’t we need better Demolition blades more than we need to even care what saw we put them in? Blades that hold up to Wood and Metal just as well, OR BETTER, than their Dedicated Wood or Metal siblings? It’s Demolition, right? It has to work a long time, regardless of what saw they’re in. Demolition isn’t zip through this panel here, chop through that bar there, Demolition is often a lot longer in any one place, right? Don’t the blades have to be able to handle that, before we start talking about what Saw it’s in? Because, I’ve always found Demo blades to be drastically lacking compared to Wood or Metal dedicated blades. Whether that be Soft, or Hard Wood blades, Metal Hacksaw type Recip blades, or Metal Jigsaw/Scroll Saw blades… Every blade I’ve every bought,from every brand I’ve tried (Mostly DeWALT, Mastercraft, and I think I’ve got some Diablo or some Bosch hanging around as well.) the Demolition blades just did not handle what the other blades could.
PERSONALLY? I would choose the DeWALT FlexVOLT, with the 9AH Batteries, and have a whole stack of them to go through. But I would also accept the reality that, using Demolition blades, I’m only going to get 4-6 hours out of the day, because Demo Blades suck for some unexplained reason, even from the really GOOD blade brands, like Bosch. The super-efficient, high-engineering, uberblades that come out of Bosch for every tool I own, are always the longest lasting, but even THEIR Demo blades… If you’re going Cordless for Demo… Look at investing in BARRELS of Blades, or you’re done in a few hours, not 12. No matter how many batteries you have.
Richard G.
I would borrow m18 fuel and 9.0 battery from HD or local milwaukee store to test it out. I had to cut 2″ stainless drive shaft couple of times and it took one and a half 4.0 batteries for that job. But that was heck of a cut. I assume, that with 9.0 battery it would last you at least half a day for various cutting needs. And for sure, don’t cheap out on a blades, replace them as they loose sharpness.
Richard G.
Mistake, it was 3″ shaft.
Mr. Gerbik
Unfortunately there is no such thing as a heavy duty cordless saw & there never will be. They trick a lot people into getting ripped off with the amp hour time. What they will never tell you is that those 3,6,9 amp hours are only good for light loaded work. That 9 hour battery ain’t worth but 20,30 minutes if you got to cut masonry, steel or anything that is in need of a lasting heavy duty tool. A battery cannot and never will be able to provide the juice that an ac receptacle can give you. It’s night and day in how corded & cordless tools are made. The parts are a lot more durable & bigger in a corded because the only parts inside of it serves the purpose of the functionality & they keep it simple. Cordless is getting worse than ever especially because of the useless tech that they keep trying to put in. Which means the parts that serve the purpose of the tool gets weaker or smaller because of some wireless crap that has nothing to do with the tool functionality. Biggest gimmick to ever hit the tool market. Some of the worst brands corded tools are made much better than the best brands cordless tools. Just about all cordless tools are very cheaply made, yet they cost almost double compared to a corded. I don’t see how they can call any cordless tool heavy duty, especially saws. But there’s a sucker born every minute, hopefully they can learn from their mistakes & spend their money more wisely.
glenn
Thanks for your advice, however I will stick with my cordless tools on the jobsite. Much better than running a half dozen time wasting trip hazards up ladders and all around where we walk.
If you turned up with only corded tools on one of our jobs you would be told to pack up and go…….very impolitely.
Anthony
Mr gerbil, you’re coming from a completely different school of thought, and that’s okay as long as you realise it’s not the always the right one. You seem to be part of the group that won’t sink a 1″ screw into sheetrock without running a 100 ft extension cord to your old black and decker drill. I come from the era where every drill on a work van was a cordless 14.4 dewalt. Sure, most everything else was corded, but cordless does have it’s place, and we are currently in a time where no company is afraid to push the boundaries of what cordless can do. I’m sure almost all of us can agree that the reader who ignited this whole conversation is simply asking for something that isn’t possible. I don’t know what kind of demo requires 3-4 saws running for 10 HOURS STRAIGHT, but if that’s what he’s looking for, it doesn’t exist. Atleast, not yet. That doesn’t render all cordless tools useless, we just have to accept their limitations and use them appropriately.
SiSiX
The question comes down simply to one of portable power and energy density. The batteries are some of the best from a technological standpoint out there, but sometimes, you really can’t take it with you.
DeWalt’s 12-amp corded recip saw pulls roughly 1320 watts when it’s running. (12 amps x 110 volts) It’s not that the cordless is weaker, or can’t keep up, it’s simply a matter of ‘how much battery do you want to carry?’ The biggest flexvolt battery is nominally a 162 watt hour battery. (18v x 9 amp hours) To run that recip saw for even an hour, you’re starting to talk about KILOWATT hour batteries. Those Tesla Powerwall batteries are about 13.5 kWh. Those would run your demo saw all day. They also weigh around 260 pounds. But it would make it through the entire day.
That’s the basic deal. Cordless tools have come a LONG way, and in many cases are actually more powerful than their corded counterparts. But the sacrifice they make is one of longevity in runtime. (Not in how long they should last, just local runtime) Until someone comes up with the sci-fi standby of portable fusion batteries, cordless tools powered by batteries are never going to be able to compare to their corded counterparts.
Sidenote: Lithium-ion batteries have about 1/8th the energy density of gasoline (there’s a LOT of not battery space in a battery pack). But even if they had parity, you’d still be changing them out every 2 hours, and if you think 9 amp hour batteries get hot under use, picture what a 72 amp hour battery the same size would be like 🙂
tl;dr : Corded tools have their place, cordless tools are meant for convenience and where you just can’t get power any other way and liquid fuels are not an option. But they’ll likely never replace corded tools in our lifetime for ‘run time’.
fred
Great reply!
Those portable fusion batteries will be a long way off I’m afraid – but there would be a lot of energy density in a tank of deuterium and tritium mix.
Speaking of mix – that 10% ethanol that we add to our gas has something like a 4% negative impact on energy density of the tank compared to 100% gasoline. (0.9X34.2 +0.1X20.9)/34.2 = 0.9611
Ict
The thing you need is the makita x2 recip saw and buy imren 3500Mah cells and case’s…make your own 10.5 amphr batteries….that’s what I did….they work great….so with one of these batteries you get about 3 times the runtime of a 5.0…..because of the 3layer cooling capacity……with this combination you should get more than twice the runetime of flexvolt 9.0……and even faster cuts….but bar case’s on aliexpress.com….and bats on eBay …get the 15..30..’s…..18650……solder strips…. .1x7mm. …..spot welder….you have the best out there…..
Nathan
Too many variables.
what exactly are they demo’ing. Steel framed industrial buildings? Or normal wood and nail construction. Some comments that just plain make sense cover the basics.
use the right blade and replace often. I mean if you’re cutting metal pipe – swap to your metal blade and USE THE WHOLE BLADE.
Back on studs use a demo – wood and metal blade for those pesky nails. Or as mentioned get some quality carbide recip blades. They cost more but under that much use – guess what – they work better longer.
I’ve used the flexvolt recip and I would say it’s as strong or stronger than any corded recip I’ve ever used. Even my larger milwaukee super sawzall. But that battery won’t run very long on full bore. guess what – it’s not meant to.
sounds like they might need to use some other devices besides recips. I mean right tool for the job is another factor and a recip isn’t the right tool for every job.. Take the steel pipe situation – again can you get a angle grinder to it? Then maybe I don’t know use the angle grinder instead.
I wish the guy luck but it sounds like an uphill climb
KB
Here’s another perspective on the question…
I’m a project engineer for a large multinational manufacturer. This year we’ve seen several upgrades in our factories involving demolition. In one particular instance, our electrical contractor had 14 men working 24/7 for 4 days. These men were removing rigid conduit among other things using cordless reciprocating saws. Most of the work was done on aerial lifts where no 120VAC was available.
The contracting firm supplied everyone with Ryobi 18V reciprocating saws and four 4Ah batteries. I asked why not use name brand cordless saws. His answer was it was more cost effective to go with high-end blades (Lenox Gold) and “disposable” saws. Because so many tools are ruined from dropping (40′ ceilings) and oil contamination from environment. According to their experience, the real expense is not equipment but man-hour productivity. He told me the disparity in quality vs price does not justify the name brand tools today – tomorrow maybe.
Joe J
Assuming they are using/swapping blades correctly.
This is simply not a proper use for a cordless tool. Battery technology has a long way to go before you can abuse a high drawing tool all day without swapping batteries frequently.
Find a way to get power to your work sites or deal with the limitations of the technology.
Samuel Thomas
I read about diablo blades in a blog. But I am not sure what are they saying is true or not. Can anyone here tell me something about it ?
Stuart
Diablo blades are good.