Well all, added a new member to the family today. Like I really needed another light....
This time I wanted something cheap that would run a LONG time, and high brightness wasn't a requirement. I went with the trusty ole Maglite 2D (incan) and a Rayovac 3V LED Drop In - all for under 20-bucks at wallyworld.
Like I said, not very bright but it is a small step up from the Incandescent bulb. Run Time = should be a very long time for 2-D's. What the hell. I can always throw in a better LED at some point in the future, but the idea is for something to use indoors when/if the power goes out and not eat batteries.
I did something similar with a cheap 2D light, except I made my own driver from a 1 cell IC that can take 3v, so it should be able to run the cells down to 0.9v total and is bright enough for normal use.
I used a large warm white LED (one of those 8mm things from eBay) and I’ve already ran it for two days straight as a test and it’s still going strong.
For me, avoiding alkalines is also important. Too often I’ve forgotten a utility flashlight in a tool bag, only to have the tail threads corroded in place.
Granted if the light is stored indoors, in air conditioned comfort it isn’t as likely to leak. But mine are often in the car or van and see summer heat.
I really value a decent, run forever, RELIABLE light.
I also bought one of those Rayovac LED drop ins for my 2d Mag. It was quite impressive until I tried the Mini Mag 2 AA w/factory LED.
The lumen efficiency per watt does seem to vary quite a bit with different LED types. I am sort of inclined to mod a 2 AA for direct drive at a medium low intensity. A set of Ultimate lithiums should last over 100 hr at 25 mA (T1 3/4 LED). Shelf life should be many years, even in a hot car. From what I understand lithiums will rarely leak (primaries or rechargeables).
An LED headlamp is also rather useful for a power outage around the house light. I’ve been using a 3 AAA version which claims 40 hr life. The beauty of it is hands free useage.
To try and figure out what was really going on, I measured 150 mA current draw with this setup and new Duracell Coppertops (the ones that came with the Maglite). Should last quite a while at that rate.
One thing that is strange is the lack of technical info about that Rayovac LED Drop In. I'd really like to know it's operation voltage range. Can it be used safely above 3V? What is it's low-voltage cutoff? It would be great to see an output % run-time chart for this thing. Lack of regulation seems to be it's biggest drawback. Perhaps I'll go with the Nite Ize since it has better regulation - and therefore should have a more consistent output.
As an experiment I took one D-cell out of the 2D Mag and tried it out and it worked on 1.5V, though it wasn't very bright. Even at that it would still be enough to navigate through a dark house in the middle of the night.
This is my quickest mod ever! I hate to brag but it took all of 3 minutes :bigsmile: No description is necessary, here are the pics. It has GREAT runtime, the down side is it has limited range…………….
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That works out to 60 lumens per watt. Cree reaches 140+ at moderate drive levels.
I am surprised that it lit at all with one D cell. Impressive!
I’ve also considered using lithium rechargeables with lights sold for alkalines. One Li ion at 4.2 volt max, less a forward diode drop of 0.6 to 0.8 volt should replace a pair of alkalines at 3.3 volt max.
