There's a very simple mod you can do that I should have mentioned earlier. Get yourself a Minimag or similar 2AA bi-pin light. Replace the batteries with L91 Energizer lithiums and replace the bulb with a white led (direct drive). You should get usable light for hundreds of hours. I used this setup as a "find the can" light next to my bed for a while.
Longest running light?
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joema
Flashlight Enthusiast
You're right, I forgot about that. Also I made a math error, the theoretical runtimes are (assuming 18650 is 3.82x the CR123A capacity):John N said:
U42 @0.3 lumens on CR123A: 300hr
U42 @0.08 lumens on CR123A: 1,125 hr
U42 @0.3 lumens on 18650: 1,146 hr
U42 @0.08 lumens on 18650: 4,297 hr
U60, U60XR @ 0.08 or 0.3 lumens: longer than the above due to improved light efficiency, amount unknown
U85 @0.12 lumens (lowest setting) on 18650: at least 2,865 hr
Running at 0.12 lumens does reduce the U85 continuous runtime with an 18650 from about 4,297 hr to about 2,865, although the U85 may run somewhat longer as it's apparently more efficient than a U60XR.
But the U60XR may have the longest runtime, since it can go down to 0.08 lumens. In that scenario (X)tended (R)untime takes on a new meaning.
These run times are so long, I doubt they'll ever be tested.
Even at zero lumens, the U60XR will eventually run out of juice, since the microprocessor itself consumes some power. However, these discussions are mostly about which flashlights can make a tiny little battery get the most hours from the small amount of energy it holds. That's important for an EDC or PSK light, but for a household light, there's a simpler approach. Use bigger batteries or more of them. The Lightwave Pro 4000 mentioned above (three D cells and ten leds) is a good example. It will make real light for several days, not a feeble glow.
Keep in mind as well (when imagining a blackout) that there are three parts to every day. 1) the daytime, when you mostly don't need a flashlight because there's daylight; 2) the nighttime, when you mostly don't need a flashlight because you're sleeping; and 3) the evening, when flashlights are most useful. You don't need to run your light 24/7. If you're trying for 7 days preparedness, then 20 hours of flashlight runtime (a little under 3 hours a day) should be more than adequate in practice. Just enjoy the blackout, and try to follow a natural rhythm of getting stuff done in the daytime, going to bed not long after it gets dark, and being temporarily liberated from TV and computers. During the east coast blackout I had a good time playing with my flashlights and ran them many hours, but that was just because I could. I only needed them for anything important for a few minutes total (when I needed to walk from one room to another in a dark building), and I'd have been fine with just a keychain led. I'd say a handsfree light is much more useful than an ultra-long-running light in a blackout.
Keep in mind as well (when imagining a blackout) that there are three parts to every day. 1) the daytime, when you mostly don't need a flashlight because there's daylight; 2) the nighttime, when you mostly don't need a flashlight because you're sleeping; and 3) the evening, when flashlights are most useful. You don't need to run your light 24/7. If you're trying for 7 days preparedness, then 20 hours of flashlight runtime (a little under 3 hours a day) should be more than adequate in practice. Just enjoy the blackout, and try to follow a natural rhythm of getting stuff done in the daytime, going to bed not long after it gets dark, and being temporarily liberated from TV and computers. During the east coast blackout I had a good time playing with my flashlights and ran them many hours, but that was just because I could. I only needed them for anything important for a few minutes total (when I needed to walk from one room to another in a dark building), and I'd have been fine with just a keychain led. I'd say a handsfree light is much more useful than an ultra-long-running light in a blackout.
leukos
Flashlight Enthusiast
joema said:
:wow:
carrot
Flashaholic
I tend to carry everything I own and use with me. I figure in a blackout-type situation I'm all set with 36 spare 123As and my G2 with a P60 LA. That, and quite a few photonlights. But I'm interested in long running lights because there's a lot less chance they'll be out of juice when you need it most (and don't have a spare).
That, and I'm just curious about extreme runtime lengths of lights.
That, and I'm just curious about extreme runtime lengths of lights.
The microprocessor power consumption will be much higher than the self-discharge. You can actually see the led glowing while the microprocessor is thinking. If the current is 1 mA, that will drain a cr123 in a few months.John N said:
You're right about single cell, I'd forgotten that part. OK, I guess a 1D (or larger) light isn't what the poster had in mind. Anyway, leaving aside all these freakish or high priced lights we've been discussing, and assuming the poster wants a down-to-earth recommendation, I suggest the Gerber Infinity Ultra. It's relatively inexpensive ($15 from Batterystation or Countycomm), plenty bright for most indoor and close range uses, compact, very tough, and runs for 12+ hours on one AA cell. The older CMG versions were somewhat nicer and you can find them on BST (they get snapped up quickly) but the new one is still a good light. The old ones were among the most popular lights on CPF. You can always scrounge AA's from stuff you find around the house (Walkman, quartz wall clock, cordless computer mouse, etc).
But as mentioned, if you want the ultimate, get a Betalight.
firefly99
Enlightened
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You mention "direct drive" mean connect the Led directly to the battery without any resistor in series ?paulr said:
Is this trick possible using E1E as a host ?
Yes, you could run a direct drive led in an E1e from the cr123, though it would be quite dim because the cr123 is just 3 volts instead of 3.4 or so. The E1e just doesn't seem appropriate for that. I've thought of doing it with a Tekna Splashlite, as mentioned. Something like a Princeton Tec Blast using two L92 AAA lithiums and an Attitude module is another possibility.
Re Betalight: I'm not sure what the legal situation is, but it's possible to buy them, legally or otherwise. Actually I don't really advise buying one, both from legal considerations and because they're not that useful. They also create a waste disposal problem because of the tritium. Tritium exit signs are apparently causing nontrivial hassles when disposed of improperly.
Re Betalight: I'm not sure what the legal situation is, but it's possible to buy them, legally or otherwise. Actually I don't really advise buying one, both from legal considerations and because they're not that useful. They also create a waste disposal problem because of the tritium. Tritium exit signs are apparently causing nontrivial hassles when disposed of improperly.
joema
Flashlight Enthusiast
paulr said:
I agree why get a Betalight if an Eternalight or HDS will run for over 1,000 hours (theoretically 4,000 hrs for an HDS U60XR with an 18650 battery).
Re legality of Betalights, the below NRC regulation apparently says it's OK providing the device is not a toy or for frivolous purpose, e.g, a Taser glowring.
Re discharge rate from microprocessor drain, I don't think anybody knows what that is. It likely varies between various microprocessor-controlled lights (Surfire U60, HDS, Eternalight, etc). It may also vary depending on whether the light is on or off.
-- Joe
NRC Regulations (10 CF) § 30.19:
(a) Except for persons who manufacture, process, produce, or initially transfer for sale or distribution self-luminous products containing tritium, krypton-85, or promethium-147, and except as provided in paragraph (c) of this section, any person is exempt from the requirements for a license set forth in section 81 of the Act and from the regulations in parts 20 and 30 through 36 and 39 of this chapter to the extent that such person receives, possesses, uses, transfers, owns, or acquires tritium, krypton-85, or promethium-147 in self-luminous products manufactured, processed, produced, or initially transferred in accordance with a specific license issued pursuant to § 32.22 of this chapter, which license authorizes the initial transfer of the product for use under this section.
.....
(c) The exemption in paragraph (a) of this section does not apply to tritium, krypton-85, or promethium-147 used in products primarily for frivolous purposes or in toys or adornments.
PeLu
Flashlight Enthusiast
joema said:
I doubt that. An U60 is more efficient as an U42, An U60XR is more efficient as an U60 and an U85 is more efficient as an U60XR.
I would expect the U85 will run longer on 0.12lm than the U42 at 0.08lm.
The processor itself will empty a CR123 cell in several years (was it 3-5?, it was stated some time ago here by Henry), so there is no need to take it in cosideration.
But we assume that the switching regulator stays in the same efficiency range for all levels, which I'm shure it does not.
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joema
Flashlight Enthusiast
That's why I said "at least 2,865 hr", because I didn't have specific data. The U85 would have to be at least 50% more efficient than a U42 to beat its run time, since the U85 is burning 50% more power.PeLu said:
Is it 50% more efficient at that low level? I have no idea. It's probably somewhat more efficient, but I don't know how much. In general the improved efficiency of the XR versions and U85 is more marked at higher output levels than lower levels.
Regardless, any HDS EDC U-series light will run longer on one battery than any other light I know of, except for a shake light or Beta light, and they're not in the same category.
I took a 4-D Lantern and made a MJLED setup up for it.
On HIGH (or switch on) the resistor in the PR base LED limits the current to 75mA on new alkline.
On LOW (Switch off) I have a 2KOhm resistor bridging the switch limiting the current to about 2-3mA (Maybe less) with new alkline.
so 4-D Alkline (15 Amp hours?) cells driving 2 mA gives 7000 hours.
It actually gives about 3x that because the current drops as the batteries go down.
so you get around 1000 DAYS of low light level from 4-D cells (or 10-20 days on high).
I leave this in my wife's laundry room incase the power goes out. She can sand still and in about 20 seconds she can see good enough to move around and turn the light on high.
wwglen
On HIGH (or switch on) the resistor in the PR base LED limits the current to 75mA on new alkline.
On LOW (Switch off) I have a 2KOhm resistor bridging the switch limiting the current to about 2-3mA (Maybe less) with new alkline.
so 4-D Alkline (15 Amp hours?) cells driving 2 mA gives 7000 hours.
It actually gives about 3x that because the current drops as the batteries go down.
so you get around 1000 DAYS of low light level from 4-D cells (or 10-20 days on high).
I leave this in my wife's laundry room incase the power goes out. She can sand still and in about 20 seconds she can see good enough to move around and turn the light on high.
wwglen
joema
Flashlight Enthusiast
In case future thread searchers find this, we were also discussing this point in the below thread, and it turns out the HDS microcontroller only consumes microamps. If you think about it, that's reasonable: embedded battery-powered microcontrollers run watches, smoke alarms, etc for years. My Seiko analog quartz watch is supposed to run eight years on one battery, and it's not recharged by light nor by kinetic motion, and the battery is much smaller capacity than a CR123A. And for all eight years it's physically spinning the watch hands, not just sitting there.paulr said:
As discussed in the other thread, modern microcontrollers often have a sleep mode whereby they take even less power.
I'd conjecture the self-discharge rate for a CR123A is greater than the HDS microcontroller power consumption from that battery.
http://candlepowerforums.com/vb/showthread.php?t=101355
