I agree totally that balance, feel, build quality are personal choice and make the saw. I like the Makita saws for overall build quality though balance on the 36v models is somewhat off.
Power is a function of torque and chain speed. So for a given amount of power to the chain sprocket, you can have your choice of relationship between torque and chain speed (sprocket rpm). Most people's choice is as much of both as possible. That's why I went to great lengths to actually try and measure what the limitations of each model I could try. Luckily many people purchased these so I could try them out. The minimum chain speed most people I have talked to like is about 1500 fpm. Under 1000 fpm you begin to wonder if the tree is growing faster than you cut. If they cut power when you hit a few hundred watts out, then all the chain speed will not help because the chain will keep on jamming due to low torque limit.
For example, the EGO brushless chainsaw claims 56v. Actually battery voltage is more like 48v (14 cells in series). The battery voltage drops significantly under load due to the higher internal impedance of the lithium cell type (about 15 milliohms per cell). They also limit the max current from the battery due to lithium cell type (3C discharge rate) to 12 amps. They drop down the chain speed to keep the torque up. Poor performance results. They could have used $6 lithium cells instead of $2 ones and easily doubled the output current. Now we are talking the same power range as the Stihl MSA.
I think cutting ability is arbitrary. Given two saws with the same chain fpm and same torque limit/response, if you put the same chain on both they should cut the same. You may have to balance the chainsaw differently or press down differently, but they will cut the wood at the same rate.
My favorite cordless saw is my Makita UC3530A that I converted to a brushless cordless chainsaw. It uses slightly modified Dewalt 36v (actaully 33v) A123 LiFePO4 packs. The cells can be discharged at 30C (70 amps) continuously and have a very low cell impedance (3 milliohm when new). I ended up with a chain speed of 1800 fpm and the efficiency of the battery, motor controller, and motor hover at 90% from 0.5 hp to 2.5 hp out. I limit the peak current at 100 amps which works to almost 3.5 hp out. I did this 5 years ago and have been looking for an off the shelf replacement (it it time consuming to build the conversion, which I have done about a dozen). The Stihl and Ryobi 36v brushless chainsaws both appear to be good saws but limited in power due to the battery technology and safety margin needed for consumer products.
Hopefully I can get my hands on a Husqvarna 536 one of these days. 3500 fpm top chain speed. I might go out a get one and return it after testing but some of my testing definitely invalidates any warranty. A few chainsaws have catastrophically failed my testing (stopping chain at high load and full rpm, over discharging batteries, etc).
Power is a function of torque and chain speed. So for a given amount of power to the chain sprocket, you can have your choice of relationship between torque and chain speed (sprocket rpm). Most people's choice is as much of both as possible. That's why I went to great lengths to actually try and measure what the limitations of each model I could try. Luckily many people purchased these so I could try them out. The minimum chain speed most people I have talked to like is about 1500 fpm. Under 1000 fpm you begin to wonder if the tree is growing faster than you cut. If they cut power when you hit a few hundred watts out, then all the chain speed will not help because the chain will keep on jamming due to low torque limit.
For example, the EGO brushless chainsaw claims 56v. Actually battery voltage is more like 48v (14 cells in series). The battery voltage drops significantly under load due to the higher internal impedance of the lithium cell type (about 15 milliohms per cell). They also limit the max current from the battery due to lithium cell type (3C discharge rate) to 12 amps. They drop down the chain speed to keep the torque up. Poor performance results. They could have used $6 lithium cells instead of $2 ones and easily doubled the output current. Now we are talking the same power range as the Stihl MSA.
I think cutting ability is arbitrary. Given two saws with the same chain fpm and same torque limit/response, if you put the same chain on both they should cut the same. You may have to balance the chainsaw differently or press down differently, but they will cut the wood at the same rate.
My favorite cordless saw is my Makita UC3530A that I converted to a brushless cordless chainsaw. It uses slightly modified Dewalt 36v (actaully 33v) A123 LiFePO4 packs. The cells can be discharged at 30C (70 amps) continuously and have a very low cell impedance (3 milliohm when new). I ended up with a chain speed of 1800 fpm and the efficiency of the battery, motor controller, and motor hover at 90% from 0.5 hp to 2.5 hp out. I limit the peak current at 100 amps which works to almost 3.5 hp out. I did this 5 years ago and have been looking for an off the shelf replacement (it it time consuming to build the conversion, which I have done about a dozen). The Stihl and Ryobi 36v brushless chainsaws both appear to be good saws but limited in power due to the battery technology and safety margin needed for consumer products.
Hopefully I can get my hands on a Husqvarna 536 one of these days. 3500 fpm top chain speed. I might go out a get one and return it after testing but some of my testing definitely invalidates any warranty. A few chainsaws have catastrophically failed my testing (stopping chain at high load and full rpm, over discharging batteries, etc).
Welcome to AS!
Thanks for the tech input. This is clearly important information for designers, engineers, marketing people, etc. It is also helpful and interesting as a potential consumer. I would love to see a spreadsheet of this info if you get around to it. You can see a partial list of products and models I compiled a few months back, about 10 posts up, but this is already out of date. STIHL already has a second model out, Oregon has announced a brushless version, Toro has announced a saw, and others keep showing up in magazines and on store shelves.
I spoke with a Ryobi rep almost a year ago in a local Home Depot about a 36 - 40 volt class chainsaw - he said that they were coming, but I have only seen Ryobi 40 volt string trimmers and hedge trimmers locally. I see them now on the HD website, but no one in the local stores seems to know anything about them, including availability. I hope that they are available soon to take a look at.
I do have to disagree about cutting ability being 'arbitrary' - any spec in a spreadsheet can be misleading by itself, and I have made the mistake in the past of trying to be 'too objective', ending up with a less satisfactory product. What matters most is how the saw cuts, and how it holds up in use. It is easy to compare objectively using standardized chains and test fixtures. Battery life in use is more important to me than calculated rates. There is also value in subjective testing, side-by-side, in similar conditions, recognizing that different end users have different needs and expectations.
The feel, balance, torque, response, and overall build quality of the saw are important to me. Some of that is clearly personal preference. I think that it is fair to consider all of this '36 - 56' volt OPE as a class, but I want to test them individually in use; not just go by a spreadsheet or price tag.
Philbert