@Feryll - I have a electric trimmer and it works fine, but I do have one big issue when using it. When I bought the trimmer I wanted electric because I thought it would be better for the environment. I also knew I did not want to be attached to a cord as I worked in the yard. I have a large yard.
I ended up buying a weed trimmer that is battery operated. I simply plug the battery in to charge and then pop it into the trimmer. I even bought a backup battery so I could always have one ready to go.
Even with two batteries, I can't get over my entire yard. So I seem to be always waiting for a battery to charge. And when the battery drops below 80 percent charged there is a noticeable difference in the power level.