But the batteries last forever.
I have several LED lights and I love em.
I have a couple of headlamp like on another thread.
My fave is a single LED that clips to my hat brim.
I have one LED light that I took under the house when plumbing and it has about 20 led and runs on three D cells.
I came out form under the house and left it to go for parts. Three days later I went back to finish and the light was still shining.
I use it now every night and the batteries that are in it were put in last winter sometime.