golden valley const.

Use the UWO of 360. 360W/18V=20A. 80% efficient so that's 25A draw.

Doubt it. In some woods it fails at 2 9/16. Maybe through an ijoist flange but not a floor. If you're running 3" pipe you need something else.

Might be about time to move to the current tools. 20v max 4.0 packs are almost identical real world capacity, and you'll have more tools and development coming down the pike.

1: Watt hours = nominal voltage time amp-hours. Nominal voltage is the average voltage over the course of discharging. 2&3 not sure and possibly, but its certainly nothing from that graph, those are high capacity cells, not high power cells. I don't think the q50b means it's different than the spec sheet.

It still bugs me that they call this a 40 watt hour battery. Sure it's 20v max, I don't have a problem with that. It's measurable. But you won't get 40 watt hours out of it.

I store my 723 vertically and it takes up very little room.

I'm a big fan of the DWX723 and just bought my second one. Quick to set up, easy to carry, supports 12' material all to the left of the blade. The replaceable material supports are flimsy compared to the rest of the stand but I haven't broken them. On one I broke the clamp release lever for the saw mount.

Yeah this would be nice. No resistor needed. The nano 18v batteries are actually higher voltage than 20v max.

I thought the brake was just shorting the motor, rather than reverse current. Isn't this switch somewhere in the trigger? Funny thing, I've also found I don't want the electric brake before, while mixing things. I just let off the trigger just enough so the brake doesn't engage. Takes a little practice.

Yes, 54V will be pretty powerful I imagine, but longevity will be approximately zero.

I'm not surprised. I wouldn't call it catching up, it's just being smart and not being brand loyal. They will use whatever is the best available as far as price/performance to keep competitive.

Those INR18650-20R cells seem to be very good too! More than 2.0 amp hours at 20 amp discharge: http://budgetlightforum.com/node/18537 Has anyone had a chance to take apart the DeWalt 4.0 packs? Are they using these great new cells too? How about Bosch?

Is that too much? Why not make a 15 cell battery. Still lighter than 36 volt. The circ saw would still be lighter than corded.

You're only missing that many of the 36v batteries available are lower amp-hours. Dewalt 36v batteries are 2.2 amp hour. The new 18v 4.0 amp hour batteries are almost as good and much smaller.

First try no extension cord if you are using one. Also might try a new 15a breaker. Some have different trip curves. A new 15 amp breaker might allow 135 Amps for the first 1/3 second tapering down to 30 amps for 10 seconds. And not tripping on 15 amps for a minute or more. The 135 amps is magnetic tripping and the lower numbers are thermal tripping, which build up over time. Shorter cords will reduce voltage drop, which can lower amperage draw for the same task, and help as well.

I'll eat my words a little, it seems like some decent cordless chainsaws exist now. The really good Stihl has about 3x the battery capacity of 20v max 3.0 batteries, but maybe a 20v max saw could work ok for limbing after all, since the Stihl did 43 cuts through an 8" log. http://www.toolsofthetrade.net/industry-news.asp?sectionID=1492&articleID=1919926&artnum=2

I want to clarify one thing that seems to be a little bit misunderstood. Voltage alone or Amps alone do not really tell us anything. Volts x Amps = Watts = Power (and I'm not talking amp-hours, that's capacity, not power). This is why an 18V drill can feasibly outperform a 36V drill. In fact, you could reconfigure an 18V 3.0 amp-hour battery to be 36V 1.5 amp-hour. They have 10 3.6V 1.5 amp hour cells after all. But power would be identical. This is why 18V seems to be the current sweet spot for flexibility, performance, and marketability. The 1.5/2.0 batteries have 5 cells in series. The 3.0/4.0 have two sets of 5 cells in series. Same voltage, double the capacity and potentially double the power. The tools and motors can be designed to draw higher amperage with the higher capacity battery. Here's where more confusion comes in. Part of the reason the 36V (actually 33V) tools were so powerful is the 10 cells they had were physically bigger, and actually 2.2 amp hours each. The new 36V (33v) dewalt packs actually have 20 smaller cells, but they are 3.3 volts and 1.1 amp hours each, for the same rated capacity. So 33V X 2.2 amp hours gives us a 72.6 watt hour battery. The new 20/18V 4.0 packs are 18V x 4 = 72 watt-hours, in a smaller, more flexible size. When coupled with brushless, it's likely we'll get more work out of these 18V drills. DeWalt and others could go a step farther and make a 6.0 battery with 3 sets of cells, that would still fit all the 18V tools, and easily outperform 36V.

It kind of seems like you're over-thinking this. I'm pretty sure all of us could be productive and make money with any pro drill, they're actually all pretty competitive. One of the reasons torque numbers are fairly useless is they don't tell you what RPM the drill is producing that torque at. All things being equal, you can double the torque by re-gearing to half the RPM, but what good would that do us? The only way to really compare would be if manufacturers published torque curves, or at least torque @ a specific RPM. UWO, while a bit confusing, is a little more useful, or it would be if all manufacturers used it. Since 725 foot pounds of torque at zero RPM is zero watts, these peak torque figures don't tell us much about how much work the drill can do, though they might tell us how hard of a knot they can power through without stalling. UWO, on the other hand, is at least a measure of power. The drills probably put out the most power when loaded to about half RPM. Solve 535 watts and 300 RPMs for torque and you get about 160 inch pounds. Not much, but obviously comparable to other top drills. But if one manufacturer started giving us real numbers like this, they would look bad to the average non-engineer consumer, so they've gotten themselves into this bind where the only thing they can do is come up with a new cryptic measurement, like UWO. For now the best thing you can do is multiply RPM in first gear by torque, and compare those numbers if you must compare between brands.

I think the problem is chains just aren't an efficient cutting mechanism. cordless circ saws usually have a thin kerf, like 1/16th inch, to make up for lack of power, and chainsaws cut what, about 5-6 times that?

To put the importance of this into perspective, all of the 3.0 amp hour batteries use two sets of 1.5 amp hour cells, which costs the manufacturer a lot more than using a single set of 3.0 amp hour cells.

I understand you don't need higher current, but the high capacity cells are only good for about 1/10th the current of the high power cells before capacity and lifespan drops off a cliff. So far no manufacturer has figured out how to do both at once. look at this chart: http://www.panasonic.com/industrial/includes/pdf/ACA4000CE305-UR18650ZTA.pdf Capacity goes down with heat and high loads, and in this case you'll probably get both.

Yeah, I do like the idea as a beam saw. It's true though about run times and power, the cordless platforms can provide what, 600 watts of power? An 1800 watt 120V chainsaw absolutely sucks, in my opinion, compared to a small gas saw. I guess for me if I know there are trees around, I pack the right tool for the job. I recently did a job where we used both the Husqvarna and the Sierra saw. Way faster to cut 2" limbs with a Sierra saw. Two pulls, I'm not kidding.

Electric chainsaws still need bar oil, and seem to be about as fast as a coghlan's sierra saw, which fits in the tool bag, carries up a ladder easily, and cuts about 1" per pull.

The higher capacity cells can't provide anywhere near the high current tools require. They will get hot, burn out, actually have lower capacity, or all of the above. The current cells used in tool batteries are just about the best available for the task.

I've been wanting this for a long time! Every time I took my cordless up on a roof setting trusses it would quit for some reason or another. Delay boom truck at $200 an hour, etc. This also seems faster than a passlode, though still slow for sheathing.