Batery powered chainsaws - when ?

[TreeClimber57]

So it isn´t that revolutionary then??

Not at all.. not really.

They are ok. We run them in our BR600 packpack blowers.. and they run hours every week and so far have had zero issues.

Also in the Kombi's we use for pole saws, etc.. But these are fairly small engines.. never seen them use in a saw yet.

 

[The Count]

actually they have the technology to make extraordinary batteries;
they developed some sylicone ones for laptops that run for a year and a half or so.
but till there, they need to sell lots of common batteries that they improve every year a bit.
that`s my 0.02$

 

[TreeClimber57]

actually they have the technology to make extraordinary batteries;
they developed some sylicone ones for laptops that run for a year and a half or so.
but till there, they need to sell lots of common batteries that they improve every year a bit.
that`s my 0.02$

The Silicone battery.. never heard of a year and half on a battery without charge, I had seen them advertised as a 40 hour laptop battery though. They are pretty decent on temperature variance.. if not mistaken were designed to replace the lead-acid battery in automobiles. (forgot all about saws in winter.. that would be another challenge for batteries which loose some of their power when at cold temps)

But.. still fairly low output.. at least when trying to drive a multi-horsepower engine. Keep in mind a 2.1hp engine would draw around 1,600+ watts of electrical energy (way more than that on startup).. and the larger saws would be over 5,000 watts running and more on startup..

To further impact the issue.. suppose we did get a battery that would drive it.. how much does a dc powered electric motor rated at 2hp weigh.. what about 7hp? And how big is it..

 

[zogger]

tough comparison

The Silicone battery.. never heard of a year and half on a battery without charge, I had seen them advertised as a 40 hour laptop battery though. They are pretty decent on temperature variance.. if not mistaken were designed to replace the lead-acid battery in automobiles. (forgot all about saws in winter.. that would be another challenge for batteries which loose some of their power when at cold temps)

But.. still fairly low output.. at least when trying to drive a multi-horsepower engine. Keep in mind a 2.1hp engine would draw around 1,600+ watts of electrical energy (way more than that on startup).. and the larger saws would be over 5,000 watts running and more on startup..

To further impact the issue.. suppose we did get a battery that would drive it.. how much does a dc powered electric motor rated at 2hp weigh.. what about 7hp? And how big is it..

--sorta hard to compare electric motors to liquid fueled engines. Two horse electric is way more powerful than two horse gas in real life use, because it has tons more torque, right off the bat, at most any rpm. Then there are different types of motors, etc, permanent magnet and so on.

I haven't built an electric ride yet, but have followed the progress of them for some years now. The garage guys (watt heads) are doing some amazing things, the tech is advancing fast there. Guys who love what they do, in any field, do better than some dude who just grudgingly hauls himself to work everyday.

Welcome to Plasma Boy Racing, home of White Zombie, the world's quickest street legal electric door slammer in the 1/4 mile drag.

Check out some of the vids and the tech that is going into these cars. It ain't a joke no more. Electric won't be replacing every application, hand held tools or rides, but it is *coming* and will be common place for a lot of applications. And like anything else, early adopters get the benefits and the fun, plus are the main ramrods on making sure the tech gets advanced. I know I am satisfied, for example, that I put some of my wallet where my mouth is being an early adopter of personal computers and also solar power. Every little bit helps to get enthusiasm going and make things viable common every day commercial products.

As for portable tools, etc, the first batt drill I had cost way over 200 clams and isn't as good as the 20 buck black and decker refurbs you can get today, and in retrospect, it wasn't that long ago. The motor and batt tech is going fast now. Well,the proof is there, stihl thinks it is viable for some applications now, and I'd say they know what they are doing as to selling stuff.

We don't have but just high end electric cars in the US now, big bucks for even the cheapest, but awhile ago I went and looked what was for sale in china and it is now common and cheap, dozens of companies are offering rides now that look from stupid toy looking to "normal" looking..

It'll get here fast now, give it ten years, it will be common. Hmm..look at computers from 1999 to what was available in 2009. Same deal, it will go that fast now. Seems to be a tipping point once "good enough" status on various mas produced manufactured items, it goes from a curiosity that only rich guys buy to commonplace, then the quality goes up fast as the price drops at the same time, and I think we have hit that tipping point the last coupla years with battery powered devices and rides now.

 

[PLMCRZY]

The Silicone battery.. never heard of a year and half on a battery without charge, I had seen them advertised as a 40 hour laptop battery though. They are pretty decent on temperature variance.. if not mistaken were designed to replace the lead-acid battery in automobiles. (forgot all about saws in winter.. that would be another challenge for batteries which loose some of their power when at cold temps)

But.. still fairly low output.. at least when trying to drive a multi-horsepower engine. Keep in mind a 2.1hp engine would draw around 1,600+ watts of electrical energy (way more than that on startup).. and the larger saws would be over 5,000 watts running and more on startup..

To further impact the issue.. suppose we did get a battery that would drive it.. how much does a dc powered electric motor rated at 2hp weigh.. what about 7hp? And how big is it..

Have you heard of brushless electric motors? They are small and very very powerful.

 

[TreeClimber57]

Brushless DC motors have been around for a while, and are used typically in many electric tools today.

If I remember correctly, their torque drops like a rock as the rpm increases.

The other issue, not sure, what is maximum rpm of a brushless motor? Will it run into the 14,000 rpm range.. and if so what is the torque there. If not then would need a transmission to gear up the speed.. and that would drop the power and torque available.

Also.. if I am not mistaken they are quite expensive.. at least when getting into the size we are talking about.

 

[PLMCRZY]

Brushless DC motors have been around for a while, and are used typically in many electric tools today.

If I remember correctly, their torque drops like a rock as the rpm increases.

The other issue, not sure, what is maximum rpm of a brushless motor? Will it run into the 14,000 rpm range.. and if so what is the torque there. If not then would need a transmission to gear up the speed.. and that would drop the power and torque available.

Also.. if I am not mistaken they are quite expensive.. at least when getting into the size we are talking about.

They used to be ALOT of money they have gone down quite a bit. Some brushless motors can turn 50k.

I agree they wont touch a 2 stroke engine just yet. But its coming! Stihls cordless saw looks like a perfect homeowner setup. Like i said i would pick one up in a heartbeat.

 

[TreeClimber57]

They used to be ALOT of money they have gone down quite a bit. Some brushless motors can turn 50k.

I agree they wont touch a 2 stroke engine just yet. But its coming! Stihls cordless saw looks like a perfect homeowner setup. Like i said i would pick one up in a heartbeat.

Yes they do have some large ones, used in electric vehicles. But in that situation torque is needed at lower rpm.. which is where these motors excel. I think if you look at any of them the torque is garbage at top end.. and no idea what it would be at 14,000rpm.. They likely will get there, but I suspect it will be 5 or 10 years before we see something powerful enough (enough hp and torque at high rpm) and cost effective to replace top end saws.

 

[PLMCRZY]

Yes they do have some large ones, used in electric vehicles. But in that situation torque is needed at lower rpm.. which is where these motors excel. I think if you look at any of them the torque is garbage at top end.. and no idea what it would be at 14,000rpm.. They likely will get there, but I suspect it will be 5 or 10 years before we see something powerful enough (enough hp and torque at high rpm) and cost effective to replace top end saws.

I personally dont think they will ever touch a 70-90cc gas saw.

 

[TreeClimber57]

I personally dont think they will ever touch a 70-90cc gas saw.

Personally I doubt I will be doing this long enough to see it touch my 200T or 361!!

 

[PLMCRZY]

Personally I doubt I will be doing this long enough to see it touch my 200T or 361!!

Your probably right!:smile:

 

[bejay]

they have been converting 50-80cc gas model airplanes over to brushless for awhile now so the technology is there motor wise, but a plane getting 5-10 minute flights pulling around 75 amps current out of a lipo battery isnt really going to cut it for a chainsaw, sure they can add use a bigger battery pack but its not even close to being cost effective the battery alone could cost more than a 50cc 2 stroke saw.

 

[TreeClimber57]

they have been converting 50-80cc gas model airplanes over to brushless for awhile now so the technology is there motor wise, but a plane getting 5-10 minute flights pulling around 75 amps current out of a lipo battery isnt really going to cut it for a chainsaw, sure they can add use a bigger battery pack but its not even close to being cost effective the battery alone could cost more than a 50cc 2 stroke saw.

How many volts are those batteries.. and how big are they.

 

[TreeClimber57]

they have been converting 50-80cc gas model airplanes over to brushless for awhile now so the technology is there motor wise, but a plane getting 5-10 minute flights pulling around 75 amps current out of a lipo battery isnt really going to cut it for a chainsaw, sure they can add use a bigger battery pack but its not even close to being cost effective the battery alone could cost more than a 50cc 2 stroke saw.

I don't imagine torque is an issue.. nor rpm with rc airplanes.

Not sure if they have the high rpm and torque issue solved yet with motors. May work well in some applications.. but can they run at 14,000rpm and maintain high torque?

 

[zogger]

thoughts of mods

I don't imagine torque is an issue.. nor rpm with rc airplanes.

Not sure if they have the high rpm and torque issue solved yet with motors. May work well in some applications.. but can they run at 14,000rpm and maintain high torque?

--I was trying to find more tech details at the stihl.de site, more specifically to try and find the engine details, a power curve graph, chain rpm speed, etc, crapped out there, but I did notice they have an optional battery pack belt adapter. Which means it should be easily modded to carry a few batts hooked in parallel. The saw itself looks robust enough in the entry level class, so maybe they will make a tophandle one.

I know I can't afford the stihl saw, but I think I will look for one of the black and decker or ryobi or whatever cheaper ones now used just to have one and play with it. I *bet* they can be modded. Proly get a BD because I already have various chargers and batteries.

They are cheap enough you could use the batt pack idea and do both a series and a parallel connection with extra batts to bump up the power and the range a little. The DC motors should be able to take more voltage to some degree before getting fried. How far, don't know, but they are cheap enough to find out. Maybe go from 18 to 30 or something. That would be the cheapest black and decker mod because those size batts are common. (older 12s and the 18s). But there's so many diff older batts out there of various brands it ain't funny, just a question of cobbing connectors for them, doesn't seem all that hard theoretically given a supply of older junked saws and the handles to use...

The stihls run stock at 36 VDC, so I imagine they could do OK for light work, and might take even beefier mods, but that's way outside my experimental price range. Take a lot of looking and speccing the wires and controllers, etc first before coming up with an outside range mod level.

Or start with one of the plug in AC models, which are cheaper and larger than the batt ones, trash the AC motor, measure what ya got for space, and see what you can do fitting a generic beefy DC motor then coming up with your own custom battery pack belt, and have the connecting cord be integral with the saw safety strap hanger. *Most* DC motors out there now are designed to function well over a wide range of voltage already, so it is just a matter of looking for size/config/acceptable weight for a saw. It really helps to open up the power and range aspects if you can go with the battery belt idea. (well, I'd add suspenders like from a normal carpenters belt or whatever, stuff I, or any of you guys, already have kicking around). Could be quite fun and you could come up with n acceptable tool for really not much. The battery stihls are ...well, stihl priced looking at what eurobucks are.

 

[The Count]

The Silicone battery.. never heard of a year and half on a battery without charge, I had seen them advertised as a 40 hour laptop battery though. They are pretty decent on temperature variance.. if not mistaken were designed to replace the lead-acid battery in automobiles. (forgot all about saws in winter.. that would be another challenge for batteries which loose some of their power when at cold temps)

But.. still fairly low output.. at least when trying to drive a multi-horsepower engine. Keep in mind a 2.1hp engine would draw around 1,600+ watts of electrical energy (way more than that on startup).. and the larger saws would be over 5,000 watts running and more on startup..

To further impact the issue.. suppose we did get a battery that would drive it.. how much does a dc powered electric motor rated at 2hp weigh.. what about 7hp? And how big is it..

it was on TV at the Science News.
I wouldn`t be surprised at all if that spec was issued together with some energy save programs and an average of x hours/day.
but still it was really impressive.
they also said they won`t equip anything with those batteries just yet. (if I remember right, they intended to equip some space rovers )

 

[TreeClimber57]

-- The stihls run stock at 36 VDC, so I imagine they could do OK for light work, and might take even beefier mods, but that's way outside my experimental price range. Take a lot of looking and speccing the wires and controllers, etc first before coming up with an outside range mod level.

Well, lets see.

The smallest saw we use is the 200T.. runs 1.6kw or 2.1hp.. 1.6kw at 36 volts would be around 45 amps. So.. if battery not right at saw you are looking at fairly beefy wires.. and the longer the wire the beefer it needs to be. This would for the most part limit the energy source to be very close to the motor, closer the better. And if drawing 45 amps.. how long would the battery last.. and if -25 outside.. what does that do to these batteries? Just wondering.

As this is also a climbing saw.. weight is factor.. so gotta keep light.. 6-8lbs is nice

Now if you step up to a mid-range saw.. say a 362.. you are up to 3.4kw which would run around 95-100 amps..

But still have not found anything related to speed and torque.. other than lots of info on internet showing how torque drops off rapidly as rpm increases.

Or start with one of the plug in AC models, which are cheaper and larger than the batt ones, trash the AC motor, measure what ya got for space, and see what you can do fitting a generic beefy DC motor then coming up with your own custom battery pack belt, and have the connecting cord be integral with the saw safety strap hanger.

I suspect the battery models will overtake the lower end AC model saws.. they were never able to build a decent saw that was AC powered due to limitations of typical 15A electrical receptacle.. which likely peaks out around 1.5kw for most models (although Stihl shows one at 1.7kw).. (giving headroom for motor startup without breaker trip). I suspect the 1.7kw of Stihl is not running power but startup power.

 

[zogger]

pro use versus...

Well, lets see.

The smallest saw we use is the 200T.. runs 1.6kw or 2.1hp.. 1.6kw at 36 volts would be around 45 amps. So.. if battery not right at saw you are looking at fairly beefy wires.. and the longer the wire the beefer it needs to be. This would for the most part limit the energy source to be very close to the motor, closer the better. And if drawing 45 amps.. how long would the battery last.. and if -25 outside.. what does that do to these batteries? Just wondering.

As this is also a climbing saw.. weight is factor.. so gotta keep light.. 6-8lbs is nice

Now if you step up to a mid-range saw.. say a 362.. you are up to 3.4kw which would run around 95-100 amps..

But still have not found anything related to speed and torque.. other than lots of info on internet showing how torque drops off rapidly as rpm increases.



I suspect the battery models will overtake the lower end AC model saws.. they were never able to build a decent saw that was AC powered due to limitations of typical 15A electrical receptacle.. which likely peaks out around 1.5kw for most models (although Stihl shows one at 1.7kw).. (giving headroom for motor startup without breaker trip). I suspect the 1.7kw of Stihl is not running power but startup power.

--I would agree that given current state of the art that for extreme demanding constant saw work, nope, batt or plug in is not practical at this time. For occasional use or homeowner use, I think it is probably good enough. For the cheap models of AC saws, the Poulan 400e seems to get a real high approval rate on amazon, compared to their gas saws. They claim 4 horse with a 18 inch bar.

Amazon.com: Poulan Pro 400E 18-Inch 4 Horsepower Electric Chain Saw: Patio, Lawn & Garden

400E

I don't have one or have ever used one, just found that. Both husky and stihl and makita make plug in electrics as well, much higher priced, specs on their various sites.

The only electric saw like that I ever had was an old craftsman with the original power sharp system and I actually liked it just fine for what it was, always worked and I regret selling it now. I used it on various jobsites like a combo fast circular saw for odd cuts that didn't need to be high precision and for some things you would use a sawzall for. It was also my wood saw at home to deal with branches and when I had free or cheap wood delivered from tree trimmers. I had no need for a gas chainsaw at the time and it fit the bill then. If you look at the stihl batt saw promo vid, that is *real* dang close to what my usage pattern was then, it would have worked.

Oh ya and the beefy DC wires, yep, did some solar installs before, working with DC gets to be spendy for long runs in the thick copper department. Shorter runs aren't bad. My current rig which goes to my RV I made portable so it could be parked in the shade and the panels run out to the sunshine, and I just went for some freebie scrounged old welder cable.

There really are two different markets, professional cutters who need half a dozen saws to take to the job and run all day and have thousands invested..then everyone else, which is proly more like 90% of saw sales.

Read those reviews on Amazon to see what I am talking about, people are sick and tired of needing a saw that only gets used once in awhile and gets clobbered by bad fuel, having to store gas that goes bad, carbs gunk up and they spend half an hour yanking a cord to make a few five second cuts, if the thing will even work then, and judging by craigslist they don't... etc.

People seem to love that cheap electric plugin saw, and the new even cheap batt saws get similar type reviews. They sometimes need to cut something decent, and the little cheap gas saws ain't working out for them at all, they hate them and can't justify one of the 4-5oo buck level saws even if they maintain it properly, because that means yet again going and dumping out the old stale mix, driving to the station and making a new one gallon batch just for a few or a dozen cuts or whatever, then the crapshoot if it will even start.

But the main point is, even the batt saws (and other do-dads) are starting to get good reviews in this market because they have gotten better, and the plugins hit the "plenty good enough" level some time back given all but the cheapest rat extension cord. The RPM issue there appears to be a non problem, whatever needs to get cut..gets cut.

 

[TreeClimber57]

--I would agree that given current state of the art that for extreme demanding constant saw work, nope, batt or plug in is not practical at this time. For occasional use or homeowner use, I think it is probably good enough. For the cheap models of AC saws, the Poulan 400e seems to get a real high approval rate on amazon, compared to their gas saws. They claim 4 horse with a 18 inch bar.

Amazon.com: Poulan Pro 400E 18-Inch 4 Horsepower Electric Chain Saw: Patio, Lawn & Garden

400E

Well first I have to agree, likely good enough for homeowner -- who can get away with occasional use and only will use it close to receptacle.

Well.. hate to say it but they are full of moldy dung.. one horsepower is 745.7 watts of energy/power. The maximum you can draw from a 15A receptacle is maybe just under 1,800 watts.. (slightly less with a motor likely)

4hp would be roughly 3,000 watts..

So all I can say is they have some mysterious Poulan horses.. that nobody else can find.

The Stihl 261 is not even rated at 4hp.. and the 361/362 is only slightly over 4hp.

 

[TreeClimber57]

People seem to love that cheap electric plugin saw, and the new even cheap batt saws get similar type reviews. They sometimes need to cut something decent, and the little cheap gas saws ain't working out for them at all, they hate them and can't justify one of the 4-5oo buck level saws even if they maintain it properly, because that means yet again going and dumping out the old stale mix, driving to the station and making a new one gallon batch just for a few or a dozen cuts or whatever, then the crapshoot if it will even start.

But the main point is, even the batt saws (and other do-dads) are starting to get good reviews in this market because they have gotten better, and the plugins hit the "plenty good enough" level some time back given all but the cheapest rat extension cord. The RPM issue there appears to be a non problem, whatever needs to get cut..gets cut.

You are right.. and I suspect the battery saws will sit in the market where the AC saws sit today.. and never will (or not for a long time) ever go beyond that.