It was somewhat overcast today so I decided to use the weed whacker to tidy up the tire garden. The string disappeared so I thought I needed to replace it. I managed to get it apart and saw it wasn't out of string, I just needed to pull some string out and put it back together. I did that and it worked! So I weed whacked until the battery ran out. My next session down there should finish weed whacking, and then perhaps I'll spray round up on the weeds.