Cordless hedge trimmers have a ways to go before matching the effectiveness of corded and gas-powered models. Regardless of the brand, homeowners complain about lack of cutting power, anemic battery life and the extra weight those batteries add.
These drawbacks aside, cordless trimmers are the best option for many homeowners, especially those with small yards or people who don't want to fuss with cords. Among battery-powered hedge trimmers, reviewers say you can't do better than the Black & Decker NHT518. It's got the power to cut through tough vegetation and a long blade to tackle large shrubs. It's also fairly lightweight (6.4 pounds, minus the batter), making it easy to handle.
The main appeal of the Black & Decker NHT518 is that its 18-volt batteries are interchangeable with other cordless Black & Decker tools. Like many cordless trimmers, the Black & Decker only lasts about 30 minutes on a charge, depending on how hard the machine is working. Cutting through large swathes of ornamental grasses or challenging the blades on thick branches will wear the battery down faster. However, users with light trimming jobs report successfully using the NHT518 for an hour or more.
Another cordless trimmer, the Stihl HSA 65 (Est. $300) , garners much better reviews in terms of battery usage and power. It's also three times as expensive as the Black & Decker and considerably heavier (10 pounds without the battery). Reviewers say the Stihl is a good choice for homeowners with large yard or lawn-care professionals seeking a cordless trimmer, but it's probably overkill for someone who just wants to touch up their greenery.