There's 4 key developments that have made cordless saws a viable proposition. I've had a few offerings before, & have been singularly unimpressed, even from 36v versions. The combination of low battery capacity in a high drain device is not a happy or harmonious marriage. However, now the game done changed!
Firstly, there's truly high-output & more importantly high torque EC motors available. The best now have equivalent power to a 1200w + mains device @ 18v, & 2400w + @ 36v. That's serious power! Ample to drive saws, grinders, SCMS, SDS Max hammers & many other high current drain devices that were previously impossible to drive adequately. In fact, a genuine alternative to mains power
Secondly, the latest generation of Sanyo Panasonic "20700" battery cells allow huge storage capacity: 7.0 ampere hours currently, & 8.0 & even 9.0 ampere hours over the next 2 years! Not just storage either; these new cells allow high current loading in BOTH drainage & charging modes. This from a conventional twin row battery pack that unlike the massive, ungainly Milwaukee triple row packs has no size or weight penalty in comparison to previous generation packs. Intrinsic to this new strategy are complete, total, seamless backwards & forwards compatibility between cells, tools & charging technologies. This allows meaningful & truly useful runtimes & workloads to be achieved. High current capacity allow usefully "professional" levels of power, runtime & charge rapidity.
Thirdly, arguably the most progressive current manufacturers are working collaboratively to provide their individual & collective expertise to the production of truly professional families of viable mains replacement power tools. All using the same battery interface, range of battery cells & EC motor & charging technologies to produce surprising outcomes.
A case in point is the collaborative relationship between the German Power Tool Manufacturers' Association members recent production of fully compatible tools, batteries & "super" chargers. Now not only does Collomix, Mafell, Rothenberger & Metabo share their individual technical expertise, manufacturing & marketing strengths, but even the North American Walter company of industrial tools have apparently signed up too. The result is, in addition to the various company's standard tool ranges now become instantly compatible with each other, but crucially each manufacturer is now (using their own individual expertise) producing best-in-class cordless table, pendulum, track & plunge saws, grinders, drills, mixers & specialist swaging tools.
Finally, the adoption of vibration sensing technology to high pressure low volume cordless industrial extractors allows similar dust extraction performance, capability & capacity as their corded equivalents. Dustbags on cordless tools are really only a severely compromised, inefficient & ultimately ineffective alternative. Yet to be released, this new sensing technology will allow professional standards of work in cordless workplaces when released in 2018.
In many ways it makes the cordless offerings of many other manufacturers seem rather crude & primitive in comparison. Most current manufacturers have yet to adopt this integrated approach to cordless tooling. Some have yet to implement even one single element!