On End Meaning

(idiomatic) remarkably long; continuously

Example:   These batteries last for hours on end.
upright; erect; endways
1843 Thomas Carlyle, Past and Present, book 2, ch. 5, Twelfth Century
  How silent, on the other hand, lie all Cotton-trades and such like; not a steeple-chimney yet got on end from sea to sea!
1913, D.H. Lawrence, Sons and Lovers, chapter 8
  When he was dried he struggled into his shirt. Then, ruddy and shiny, with hair on end, and his flannelette shirt hanging over his pit-trousers, he stood warming the garments he was going to put on.