:laughing: They make double walled mugs. The space between the two walls is supposed to be insulation. I had the crazy idea that it would be cool to use that space to hold the beverage and have the light works inside as I have done. Some kind of a “sippy cup” mouthpiece feature for drinking from would need to be implemented / invented. :person_facepalming:
I decided to do some run time tests. The first one was perhaps ill planned. Running at level 4, approximately a 25% power setting of around 350 mA, according to theory. The run began with all 4 cells at 4.1 volts. Twelve (12) hours later the voltage, after a short rest, was reading 4.03 volts. I’m thinking I should have used a single cell to spped it up, although drawing 4x the current from a single cell may not correlate exactly to the lower draw on multiple cells. I don’t know; I am guessing and extrapolating from lead acid experience.
Anyhow I stopped that test and am recharging. At that rate level 4 should last a few days. I may run this again when I don’t feel so impatient.
My second bout will be on level 5, approximately 50% power, or 700 mA. Four cells or a single? Have yet to decide.
I should also do some “tailcap” current readings to see how close the actual flow is to the theoretical programmed levels. I’ll do that after the 50% run time test.
Wow, a good lantern !Nice mod! :+1:
Just completed a run time test using a single 30Q, 3000 mAh cell and running the light on level 5, 50% power = 700 mA.
The cell had been recently charged. Voltage reading at the beginning was 4.20 volts.
After 3.25 hours the light was shut off, I went to bed. In the AM the cell read 3.71 volts.
After a total run time today of 5.5 hours the cell voltage read 3.22 volts after being given a 30 minute rest.
I ran it another 30 minutes, for a total 6 hours and shut off. The immediate voltage reading was 3.07. 15 minutes later the voltage had recovered to 3.10.
I ran it another hour, actually 58 minutes and picked it up and headed to the shop with it still on. On the way the lamp blinked three times. As I reached the workbench it began to blink. The voltage read 3.01 volts.
The Nanjg specs state that at 2.9 to 3 volts this is exactly what the driver should make the light do.
For the last hour run the brightness level appeared to be decreasing. Bumping to level 6 did still increase brightness. It did not appear to be as bright as before, but since I have no meter that is a purely subjective statement. I do have a meter on order though. 
Anyhow at the sixth hour the brightness can still be called servicable. If we multiply the 6 hours by 4 (cells) I believe it is safe to say that we have about 24 hours os useful service from a full set of four cells, when run on level 5. Good enough for me I’d say.
I forgot to note that on level 5, the heat sink ran about 20 degrees F higher than the ambient air temperature, whereas on level 4 it ran about 8 degrees F warmer.
Everybody (here in US and Canada) have a great Labor Day weekend. Stay safe but have fun.
That’s a pint o’ light. :+1:
Well I am embarassed. 
I was showing the light to my son on the weekend. Suddenly I became aware that there only appeared to be three 7135 chips in place on the driver. It can be difficult to see clearly around the upper area where the mug walls turn inward and then upward again. Sure enough, close inspection found only three 7135’s. Photos before 8/27 show 4 chips! 8/27 was about when I disassebled major components as I changed some design elements. I must have lost one 7135 as I heated the upper plate to change the driver to the new plate. Or lost it during the reassembly. Too much heat and not enough attention.
I did think the run times I had obtained were impressive! Rightly so considering the light has been running at 3/4 of what I thought it was. But all to the good; 3 x 7135 do seem to be quite adequate for the lights purpose.
Doh! :person_facepalming: At least it wasn’t the mcu that fell off.
I would have noticed that a bit earlier though. :person_facepalming: 
So this morning I went and measured with meter… I should have done that before and I would have realized something was amiss.
Top row is the asked for percents for the levels, 2nd row the calculated values based on 3 x 7135 = 1.05 amps. 3rd row is measured value
2% …6% …15% …25% …50% …100%
21 mA … 64 mA … 158 mA … 262 mA … 525 mA … 1050 mA
19 mA … 59 mA … 145 mA …255 mA … 501 mA … 1031 mA
Now if I could make some lumens sense…
I don’t think a regular integrating sphere will be able to measure it with another degree of confidence given the radial output and complete lack of any “beam” so there wouldn’t be other similar lights to calibrate from. Best comparison might be measuring some standard lights with diffusion caps for relative numbers but even then the actual lumen output measured could be way off. I think “best guess” will be as close as anything.
A while ago I tried to envision a way to make a chandelier bulb by illuminating a hollow Chrystal shaped diffuser but this would be an ideal way to do that or make illuminated costume jewelry. Somebody get rich and remember me. :money_mouth_face:
I was thinking it was a problem; more a subjective thing than objective with the equipment available.
I should note that all along the planning stage I was thinking 4 x 7135’s mightbe unneeded. DBSAR is quite happy with only 2 or 3 - 7135’s on his SRK lantern project.
What’s necessary really depends on what you’re doing. I’d want more light in the OR than in my bedroom and more light for fine solder work than for cooking. For a lantern to while away the hours of a storm reading it may or may not need more. Chances are you’d be fine just sitting close enough to it.
This the the “while away the time” and not trip over stuff when the lights go out or when camping type of light. We have other assorted lights for detail work, etc. etc. Not having a super bright setting gives more of a guarantee the light will stay lit longer.
I’ve done a couple of ceiling bounce comparissons. I find they waste more light illuminating the ceiling and upper spaces. Also that doesn’t work outside. :person_facepalming:
great work I’m loving all the effort that goes into these hand made lights
Very…VERY inventive! What a thought…what an execution of the thought. You hand building guys are just tough critters. Really enjoyed the read!!
Thank you for every image & share!! TL
For the heck of it I removed the heat sink and ran the light on high, maximum 1050 mA. After a half hour the metal lid where the heat sink used to be registered 22 degrees F higher than the room ambient temperature. Considering that a prior test on level 5 (525 mA) with the heat sink in place registered 20 F above ambient, I may leave the heat sink off for a cleaner look. Using the light around home and at the cabin in the mtns. I find myself usually operating on levels 1, 2 or sometimes 3. so heat is really not much of an issue.
Nice. Haven’t been in here for some time. That’s one sweet mug-o-light you built there. Lot’s of different materials that had to be machined and brought together. Congrats
Is this the first successful remote phosphor build here on BLF?
It’s the first one I’ve seen and a perfect application. I didn’t even know it existed before.