A 24- or 48-volt lead-acid battery spins a rotary blade at 3,500 rpm;
$300–$460. Shown: Black & Decker 24V CMM 1200, $400; blackanddecker.comPros:
Quieter than gas-powered engines; little maintenance beyond blade sharpening; rustproof plastic deck; no emissions; easy to start. Cons:
12- to 24-hour charge times; cuts for only 45 minutes on one charge.