Found this at the local Wal Mart! A no-name keychain led light from Energizer for a grand total of $4.82!
It is operated by a bush button with no provision for locking it in the on position. It has two split rings held together with a swivel. On fresh bateries (2 x CR 2016 LI)it is brighter than my AAA LE...300ma vs 218ma on my photocell set-up.
Access to the batteries is gained by removing two tiny screws and removing the back. The push button slides AWAY from the led and takes the top battery with it (battery is stuck to the button). The second battery comes out by turning the light over. The bottom battery goes in + side down and the second goes in + side down. The push button slides back on the leg of the led to complete the battery change. The leg of the led is used as the spring for the push button. Very simple design, the batteries are placed between the legs of the led and the push button pushes the negative leg onto the battery while the positive end of the battery sits on the positive leg of the led. Now hunt the two tiny screws down and put the case back together.
The front of the package claims "20 hour runtime between battery changes." On the back, in small print, it says; "Coninuous 20--hour run time when used with lithium coin cells.." The light comes with a lifetime guarantee.
Hey, for less than $5.00, not a bad deal IMHO!
Good stocking stuffer for the Holidays!
If like a photon then it will run for several hours BUT after the first hour it will be a small fraction of it's original brightness and then dim slowly after that. Question, in the picture without the batteries, is the LED held in place? With a photon II, the whole LED and switch assembly will come out when changing batteries unless you're very careful as they are not locked in place.
Roy, off topic but can you please post the link again to the site that contains your runtime graphs? This time I promise I will bookmark it!
The led is held in place by friction. If you look real close you will see a lip around the base of the led that fits in a grove in the housing. It is not glued in, so it can be removed. In some lights there might a loose enough fit to allow the led to fall out, but not in the one I took apart.