I've only had the trimmer for about a month but, so far, I am quite happy with it. I have about 1/3 of an acre and one battery is plenty. In fact, if I rush, I can actually get two trimmings, a week apart, out of one charge. I was a little worried about how strong it would be but it has happily cut through even some vine-like weeds with no problem.
Black & Decker 18 Volt 12 in. Cordless Grasshog Trimmer/Edger is recommended by Clearbluelou
Cordless electric trimmer provides hassle free trigger starting along with an adjustable auxiliary handle which adjust to user's height. A AFS™ system uses centrifugal force to automatically advance line when needed. 12 in. cut path cuts more area per charge than other cordless trimmers. Groom N' Edge™ converts from trimming to edging with the touch of one button. Includes two batteries.