Mike Guertin, circular saw reviewer for Fine Homebuilding, says he seldom uses a corded circular saw for his remodeling jobs anymore, finding that the 28-volt Milwaukee V28 0730-22 (*Est. $400) offers enough power and stamina, along with much more comfort and convenience than corded alternatives. The 6.5-inch Milwaukee V28, powered by lithium-ion batteries, incorporates the best features of the corded Milwaukee sidewinder saws, but at 9.4 pounds, it weighs a pound less. Milwaukee guarantees the 3-amp-hour V28 batteries for two years, and the saw itself carries a five-year warranty.
A review at the Journal of Light Construction praises this Milwaukee circular saw's comfort, adding that, "it feels sturdier than any other cordless saw I've used." A more recent comparison review at Tools of the Trade criticizes the blade-depth gauge and says the setting tends to stick; otherwise it's excellent. Like most cordless circular saws, the Milwaukee V28 0730-22 saw is left-bladed (which gives an excellent view of the cutting line), with a 6.5-inch blade that can cut 2X lumber even at a 45-degree bevel.
The main drawback to the Milwaukee V28 0730-22 is its price, but experts say lithium-ion tools can pay for themselves in the long run since both battery life and runtime are doubled, compared with NiCad and NiMH batteries. Lithium-ion batteries are also the most environmentally-friendly type. They keep a cordless saw running at full power till the battery charge is completely gone (with a "fuel gauge" to estimate remaining runtime) and stay charged for a long time while stored -- a boon to anyone who doesn't use a saw every day.
Several reviews recommend the four-piece V28 tool kit as the most cost-efficient choice, since all four tools can share the same batteries and charger. The 28-volt Milwaukee 0928-29 (*Est. $600) kit includes the circular saw plus a hammer drill/driver, reciprocating saw and work light (plus charger, two batteries and carrying bag.) The Milwaukee drill-driver is one of the top-ranked cordless drills in reviews.
Several reviews recommend the lighter, less expensive 18-volt Makita BSS610 LXT (*Est. $350), which weighs just 7.1 pounds and includes a dust blower and twin LED lights. The Makita LXT lithium-ion-powered tools use a four-pole motor, which is more efficient than most tool motors, so you get more power for the weight. Reviews also note that Makita power tools fit smaller hands better than most others do. Tools of the Trade finds the Makita powerful for its weight, but notes that the blade brake is slightly slower than some. The batteries recharge in 45 minutes, and Makita provides a three-year warranty on the saw, with one year on the batteries.
Reviews praise the four-piece Makita LXT406 (*Est. $450) kit which adds a circular saw, hammer drill/driver, work light and reciprocating saw. The similar Makita LXT405 (*Est. $480) kit substitutes an impact driver for the reciprocating saw. If you already have another Makita LXT tool and battery kit, you can get the circular saw by itself (minus battery and charger) as the Makita BSS610Z (*Est. $170).
If a lithium-powered circular saw is beyond your budget, reviews recommend the 18v NiCad DeWalt DC390K (*Est. $220). It weighs 8.7 pounds, with a magnesium base and upper guard. The main drawback reported by owners is that the safety switch can get clogged with sawdust. Reviews also recommend DeWalt kits that combine this circular saw with other tools. A Fine Homebuilding review of cordless kits names the two-piece DeWalt DC988SA kit, now the DC2PAKSA (*Est. $350) its "best value." This starter kit includes the circular saw, hammer drill/driver, two batteries and charger.
For infrequent use making rough cuts, reviews at both Fine Homebuilding and Workbench recommend the 5.5-inch Ryobi P500 (*Est. $60, $110 with charger and battery), available in various Ryobi ONE+ cordless tool kits. This is really a trim saw for light use, but it can make 90-degree cuts on standard 2X lumber. The review at Online Tool Reviews is mostly favorable, but notes that the "one-hour charger" takes closer to two hours to fully charge the batteries. The Popular Mechanics review says the Ryobi P500 circular saw is okay, "but only when treated gently."