HI Andries,I find that some of the flashlights do need a bit more shaking than normal. Please shake the ones that don't work for 5 minutes flat and you will see that they will "kick"into life. Our returns on these flashlights are less than 1 % (that's 1 unit per 80 sold) Also, you will notice that the more the flashlight is used (shaken), the less shaking it requires to offer 5 minutes light.RegardsPaul Responded 30 Apr 2007