Like gas hedge trimmers, cordless electric hedge trimmers increase your range by freeing you from a cord, but they're quieter, cleaner and easier to start than gas trimmers. Cordless electric hedge trimmers are generally less powerful than their gas and corded counterparts, and their battery packs make them heavier than corded trimmers. Nevertheless, owners and experts praise their maneuverability. The 18-volt Black & Decker NHT518 (*Est. $80) is recommended by more reviewers than any other cordless hedge trimmer. Because of its shorter blade, its weight is comparable to that of our Best Reviewed corded electric pick, the Black & Decker HH2455, but this cordless model lacks both a safety lock-off switch and a lock-on switch for continuous trimming.
About.com landscaping guide David Beaulieu gives the NHT518 a good review after using it over the course of several weeks. He says he charged the battery for nine hours before the first use (it takes three to six hours to recharge after that), then used the trimmer intermittently. After three weeks the battery was still charged, and the NHT518 was "still cutting perfectly." This cordless Black & Decker hedge trimmer also receives high ratings from owners posting reviews at Amazon.com, who say it's powerful and works well for years. Owners posting at Lowes.com praise its comfortable, lightweight design and ability to cut through 3/4-inch-thick branches. The main complaint is the limited battery life -- some say the NHT518's runtime can be as short as 15 minutes, and seems to diminish over time. As is the case with other Black & Decker hedge trimmers, the warranty period is two years.
The Ryobi P2603 18-volt cordless hedge trimmer (*Est. $100) also receives praise in reviews. It has an 18-inch double-edge blade and uses lithium ion battery power instead of nickel cadmium (NiCd). Experts say lithium ion batteries don't self-discharge, so they can be stored for months at a time without losing their charge. They also deliver longer runtimes than NiCd batteries. Reviewer Joanne Richard, writing in the Ontario, Canada newspaper The Northern News, recommends the Ryobi hedge trimmer after trimming hedges and vines in her yard. She says it is surprisingly powerful, and "the large Gripzone handle makes handling comfortable and easy to control every which way you trim things up."
We found more than 30 owner-written reviews at HomeDepot.com for the Ryobi P2603 hedge trimmer. Users say it's lightweight, easy to maneuver and runs for a long time between charges (about two hours, according to one). In addition, Ryobi One+ power tools all use the same type of 18-volt battery, so batteries from other One+ tools can be used as backup. A lone dissatisfied reviewer complains that the cordless Ryobi hedge trimmer doesn't sever branches as cleanly as a manual clipper. The Ryobi P2603 weighs virtually the same as the Black & Decker NHT518 hedge trimmer and has a two-year warranty.
Stihl recently introduced a commercial-grade 36-volt cordless hedge trimmer, the HSA 65 (*Est. $300 + battery & charger) , which has a 20-inch blade and weighs about 10.5 pounds. Like the Ryobi P2603, it uses a lithium ion battery. However, the battery (*Est. $150 to $260, depending on model) and charger (*Est. $50 to $90, depending on model) must be purchased separately, making this hedge trimmer a much more expensive option. Popular Mechanics and ThisOldHouse.com rave about it, though, saying it's as powerful as a gas hedge trimmer, minus the attendant fumes and required engine maintenance. Popular Mechanics editors named the HSA 65 one of its top products of 2010; their write-up notes that "a single charge provided more than enough power to completely trim and shape a good-size yard during our tests." Stihl hedge trimmers carry a two-year warranty.