This is something I think some of you may like to know about. I had a pack of Drurcell MN1300 D cells that I had put on a basement shelf long ago and just found them this morning. They are dated January 2001. I thought being that old that they would have self discharged. Anyway I put the 2 of them into a good (2) D cell flashight and turned it on. It lighted up nice and bright and stayed pretty good for about 3 hours and then started to dim. At 4 hours it was pretty dim so I removed and trashed them. Now brand new Duracell, or Energizer or Rayovac size D cells would give longer use time, but I think it's pretty good when the old ones which had expired 6-1/2 years ago could still be of use. Keep in mind that this is not a cold basement and it's pretty dry. I have some brand new ones dated June 2013 and put them in my refrigerator. In say 7 or 8 years (I'll keep them on ice during power failures) I'll try them out. I did get 10 hours from new ones in the same flashlight and it's still bright. I'll see how it is later tonight and also in the morning and will update this post then. The lamp (bulb) is the common PR2 type and not some fancy high brightness gas filled kind.