By late last summer I had absolutely had it with gas powered string trimmers. I researched battery powered units and the most highly recommended one was a 24 volt unit Sears sold. It was made by another company whose name I can't recall. Both companies sold essentially the same tool for about $125.
I have been using battery operated power tools professionally for 25 years, and have found out that getting an under powered tool for a job will never work out.
I never could find a 24 volt trimmer last fall or winter without mail-ordering it. Today I was at Walmart and they had what looked like the very same unit, but this ons was being sold by WeedEater. They just came in last night, and weren't even priced yet.
I had the clerk check the price, and it was $74.95. I bought it on the spot.
This unit isn't intended for wacking shrubs, small saplings, or woody plants. It is made for cutting grassy plants, it works quite well for this. I ran it for about an hour today, and didn't have any more weeds to wack. Its only downside is the cutting swath isn't what the gas trimmer's are, but it does fine when used in a gentle arc type sweeping motion.
The biggest plus to me is the Wife said she would gladly use it, but flat out won't use a gas trimmer (and hasn't in the 20 years I've known her).