5761 w/ A123 - Soft Start Needed??

Hey LuxLuthor,

Wanted to bounce another observation off you. I have 16 of the Sanyo 2700s and 16 of the Sanyo Eneloops AAs. I like the 2700 but love the Eneloops. One thing thou about the Eneloops. They definitely hold their charge better but I have noticed that they hold their voltage better also. Have you noticed that after a few days the Eneloops still have a relatively higher voltage than the 2700?

Fulgeo said:

The 5761 bulb generates a fatter more usable beam.

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That is basically why Northern Lights likes the 5761.

richied said:

mag 3c, 2 emoli 26700a's, 5761 bulb and AW 3 stage ...

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Northern Lights (and jimjones3630, I think) went to 3C to use 2 x emoli and 2 x A123, with the NTC soft-start to prevent instaflashing. There're a lot of posts by them about it; Northern Lights has given a list of links to the main ones in some of his posts, so they're easy to find.

richied said:

Do you know if the emoli's are slightly narrower than the A123s? I had to do a lot of brake hone boring with the 3c and remove cardboard and retape the a123s to get them to fit. I'm not comfortable with the setup, I think the a123's could possible melt the mag body if they should ever short thru the tape!

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They mustn't short through the tape; the tape must stay intact. (Should be Kapton tape. http://www.kaptontape.com for explanation.) Also see Northern Lights posts re using 10A blade fuse in tailcap.

Here are some dimension measurements by petrev (slightly edited by me):

--------------------------------------------------
cpf Petrev diameter measurements (mm)
--------------------------------------------------

Mag D ID 33.

old Mag C ID 26.30 (no C in serial number)
new Mag C ID 26.24

standard C alkaline (Duracell)
26.20
AW C Li-on 25.62

A123 26650 26.91 cardboard sleeve (too big for Mag C)
A123 26650 25.91 bare
A123 26650 25.99 parcel tape (brown) fits
A123 26650 26.21 parcel tape (multi-layer) fits very snugly


Emoli 26700 26.60 cardboard sleeve (too big for Mag C)

Emoli 26700 26.10 bare
Emoli 26700 26.24 parcel tape (brown) fits old C snugly
fits new C exactly / just too big (depending on tolerances?)

standard D alkaline (Duracell)
Diameter 34.2mm
Length 61.5mm

standard C alkaline (Duracell)
Diameter 26.2mm
Length 50.0mm

cat,

thanks for the battery dimension info and links, especially the kapton tape...been trying to find some, was going to wait for the MIT flea market here in MA to start again in April...lots of parts and hard to find supplies like that. Youdoit electronics said they didn't stock any( a local good electronics store in Needham MA).
I will search for the threads you mentioned. Looks like the emoli's will be a pain to fit..just slightly wider than the a123's which took hours of honing to get them to fit with just thin plastic electrical tape. I don't like the use of this tape since it could rip easy and short the cell. will definitely order a roll of the kapton.
Anyone have suggestions on brake honing techniques to open up a mag body? I found that I had to use some oil to keep the aluminum from galling, I'm not sure if this is the best way to do this? Lower rpm better?....i'm using an old electric drill with one speed only and it may be too fast.

richD

richied said:

cat,

thanks for the battery dimension info and links, especially the kapton tape...been trying to find some, was going to wait for the MIT flea market here in MA to start again in April...lots of parts and hard to find supplies like that. Youdoit electronics said they didn't stock any( a local good electronics store in Needham MA).
I will search for the threads you mentioned. Looks like the emoli's will be a pain to fit..just slightly wider than the a123's which took hours of honing to get them to fit with just thin plastic electrical tape. I don't like the use of this tape since it could rip easy and short the cell. will definitely order a roll of the kapton.
Anyone have suggestions on brake honing techniques to open up a mag body? I found that I had to use some oil to keep the aluminum from galling, I'm not sure if this is the best way to do this? Lower rpm better?....i'm using an old electric drill with one speed only and it may be too fast.

richD

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Man we are covering a lot of bases in this thread! Here is a description of Kapton. The 1 mil thick is best, even though the adhesive layer adds a bit to that making it not truly 1 mil thick. This site has 50% discount for 1 roll samples.

McMaster-Carr is another place to find it. The reasons people promote Kapton is its heat resistance, electrical insulation, and resists solvents.

The simple "packing" tape adhesion layer melts at low temps typically seen in our hotwires, resulting in a gooey mess...and easily transfers to the inside of the tube. Yuck!

Now regarding the brake honing. Use the coarser (larger size) tri-stone #275 at top here. I think it is important to use a portable, reversible drill that is not real fast like many electrics. I also use my portable drill in the kitchen sink with a slow trickle of cold water. It keeps the aluminum dust out of the air, washes away the slurry, and keeps it cool. Amazingly, the stones and KD Hone are not affected by the water....and it helps keep the stone from clogging up.

Too long of a thread to read it all so I will just answer the first post. A 3C host with two A123 cells will run a 5761 without soft start just fine. I have one that I use the heck out of. Vbulb is 9.9 volts, yes, because they are flat discharge you get higher than the rated nominal voltage. 9.9Vbulb is good with a 5761 as almost if not all will run on that without soft start, above that as you approach 7.1 you will find bulbs that will flash even with soft start.
With the 3C host to get the 9.9 Volts at the bulb you need to do tail cap and switch mods to reduce the resitance.
There is plentay of room to put in a charging jack too. A123 will charge just fine in series with the right charger.
Search 5761 key work. Jim Jones and I have posted a bunch about this as well as our bud, Lux.
tail cap and switch mods with jack


3C host next to a 2c which has an AW spacer

LuxLuthor said:

As I told you in the PM, with the link to the A123 Data profile showing the voltage ???....so I don't see the point in using two A123 18650 cells here.

The Eneloops have 1.45V hot x 6 = 8.7V​

2 x Emoli will be about 4.15V hot x 2 = 8.3V​

A123 IMMEDIATELY drop under load to 3.3V x 2 = 6.6V​

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Oh, well, I had to speed read through this thread, having messed with most of the stuff surrounding the emolis, A123 and 5761. I tacked onto Lux's post because it is a good intorduction and starting place.

Here are some of my observations:
In more than one light with two A123 26650 the 5761 do not dop to the expected 6.6 or less Vbulb but have a flat curve down from 6.9V at the bulb. It does not seem to be enough of a load from this bulb to do to drop to the expected nominal voltage. The voltage stays up longer than the Emoli too, simple side by side testing shows after several runs to bring the battery down, run tests, that after a few minutes the A123 5761 runs brighter. Usually when you turn the lights on together the emoli is brighter at onset but dims faster. Running the various 64430 we ran on 3 of the A123 cells also demonstrated voltages slightly higher than the expectd 9.9 vbulb too.

The emolis also work great but you need soft start and some control because the overhead voltage, Vbulb is more like 7.32 volts on direct drive emoli. Vbulb 7.1 is about all that 5761 bulb can handle, I was getting some flashed bulbs at 7.3 Vbulb. The NTC posted now in a zillion posts worked good most of the time but recently I got a few that were way on the end of the factory specs for tolerance and were delivering too much residual resitance and were cutting the end voltage too much. I need to get some more like the first bunch. They dropped voltages by 0.3 volts on the 5761, they added 0.06 ohms resistance when in equilibrium.

Emoli and A123 need to be rewrapped in shrink or Kapton, forget the cardboard tube.

I take Vbulb readings with a meter hooke parallel righ into the bulb pins in a working light.

Northern Lights said:

Too long of a thread to read it all so I will just answer the first post. A 3C host with two A123 cells will run a 5761 without soft start just fine. I have one that I use the heck out of. Vbulb is 9.9 volts, yes, because they are flat discharge you get higher than the rated nominal voltage. 9.9Vbulb is good with a 5761 as almost if not all will run on that without soft start, above that as you approach 7.1 you will find bulbs that will flash even with soft start....

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NL, with much respect, if you are saying that each A123 cell is charging up to 4.95V and holding that to run the 5761 bulb, I must disagree. :kiss:

"There ain't no way" the A123 have that kind of voltage capability. There is also no way that the 5761's I have used will hold up to that high (9.9V) voltage without flashing. With two Emoli it is also not critical to get rid of as much resistance, since they start out at 8.3V, and you want some blunting resistance to remain in the light....in addition to the NTC. My ideal setup is using them in an AWR Hotdriver 2D Mag.

I was talking about 2 x Emoli vs. 2 x A123 in the larger 26mm sizes. If you are using the used/abused Emoli cells that have been sold by another member here at CPF, I'm not using any of those cells. I had to throw half of them away on arrival due to signficant damage to shells, and the other half were not close to the same performance scale of the new Emoli that I gotten elsewhere. It became apparent to me that these were end of life Emoli that someone was dumping on the EBay market, and I would not draw any performance conclusions on those cells.

The quality Emoli cells hold their voltage from 4.15 down to 3.5V, which is about the level when I stop using them and recharge. In my experience they delivered a higher voltage and brighter 5761 than the A123, until the Emoli got down to end of capacity. Given the hassle of the A123 lower voltage & unique charging protocol (to maximize cell life), I have almost entirely switched over to Emoli.

It may be true that the overcharged A123 start out at 3.5V for a very brief period of time before dropping towards their default 3.3V level when subjected to only a 5 to 6A drain rate, but clearly the objective testing profiles do not support the notion of their staying at 3.5V at any time under load as shown on page 3, (use interpolated curve closer to the black 10A graphed line as related to the 5.5 Amps used by 5761 bulb.

I think NL meant to say 2xA123 cells deliver 6.6volts to the bulb not 9.9volts. He just made a little typo. The point he was trying to make was that the 5761 runs bright with 6.6volts with little to no chance of flashing the bulb. The A123 cells deliver and do not get crushed by the 5 Amp load of the 5761. Anyway I will shutup now and let the big boys talk.:D

Northern Lights said:

Too long of a thread to read it all so I will just answer the first post. A 3C host with two A123 cells will run a 5761 without soft start just fine. I have one that I use the heck out of. Vbulb is 9.9 volts, yes, because they are flat discharge you get higher than the rated nominal voltage. 9.9Vbulb is good with a 5761 as almost if not all will run on that without soft start, above that as you approach 7.1 you will find bulbs that will flash even with soft start.
With the 3C host to get the 9.9 Volts at the bulb you need to do tail cap and switch mods to reduce the resitance.
There is plentay of room to put in a charging jack too. A123 will charge just fine in series with the right charger.
Search 5761 key work. Jim Jones and I have posted a bunch about this as well as our bud, Lux.
tail cap and switch mods with jack


3C host next to a 2c which has an AW spacer

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2x A123 on that light is Vbulb 6.9. Yep, a typo. What surprised me and I attribute it to the fact the battery has one of the flatest if not the flatest discharge curves out there is that at the draw of the 5761 it starts out at 6.9 volts at the bulb after that first moment of initial drop in voltage. I was expecting 6.6vbulb but it has always been higher than that with several sets of cannibalized batteries.

The emoli start out higher and the residual resitance from an NTC that is at 0.06 ohms when use will drop the voltage 0.3 volts and also give 6.9 at the bulb. I find that about half way through the battery charge when you turn on the Emoli and the A123 in a side by side the Emoli appears a little brighter but will dim belong the A123 if you allow the run to continue for a few minutes. Cool the lights and you can repeat that a few more cycles. In the lights I did test side by side when the bulb took a noticalbe dimming and off color I called it quits, the emoli went out before the A123 but this was so close I would not bet on it for every set of batteries out there.

I like the emoli idea too and have been switching when I make one here or there. But I now find the NTCs may not have tolerances tight enough to depend on that 0.06 Ohms at stasis, I have two that ar at 0.24 ohms or 4x the expected resistance. Time to look at available alternatives.

Too late, too tired and I was also thinking about the 64430 where I try to keep it at 9.9 from 3x A123 and these are the 26650 cells, 26mm diameter, 65mm long, 0 for round.

I will post here a discharge chart for the A123 that is very interesting a little later, maybe this evening.
Gee Whis guys!! while I was trying to edit this two other posters headed into the fray and I got cut out before I finished, Well, here it is, voltage v. minutes the grey and red line are the A123 on the 64430, you can extrapolate and see what I mean about it holding 6.9 Vbulb on the 5761, these grapsh were done by a fellow that was looking for a power solution, they are not the best possible condition factory authorized published data, this is what really happened, at least on this guys bench.

quote from the guy who did the graphs for me:

that is quite likely the best direct-drive solution of any flashlight
of ever...

this is the 64430 light comparing the hotdriver vs NTC direct-drive
solutions.. as always i used 30mohm ckt resistance and for the NTC i
used 45 mohm.. half way between 60mohm for 5A and 30mohm for 10A...

the solid lines are the hotdriver solution and the dotdash lines are
the NTC DD solution..

there is a bit of a spike in the beginning.. it should be not a
problem, the lamp re-rates to about 6 hrs even at the 'spike'
voltage.. and without the NTC i'd be concerned.. non-issue with the
NTC..

This thread has more tangents and rabbit holes than a Arkansas deer trail. A lot of info and must admit only ready a few posts.

A123 2200 mah cells out of Dewalt 36v battery paks 2 of them do not need a NTC or soft start to power up 5761. I specify these batteries as I have noted often confusion with other batteries.

Rich, you are using 18650 A123 and can that is like comparing apples to oranges. all of NL and my research with A123 cells has been with the 2200mah cells out of Dewalt 36v paks.

What we do here is push bulbs, batteries, circuits, and human patience to the wall. So I consider A123 cells from any other source a different battery and indeed that is true. Even if Dewalt 36v battery paks where made at another plant along with the plant in Canada I would redo the work up to test those batteries and not make the mistake of assuming they have the same level of performance.

NL has said all there is to say I can only say 1+, me to. these A123 batteries are the flattest discharging cells or should say flatter than Emoli cells and flatter than any cells I know.

RichS said:

Ok, after my Mag85 spanked my 5761 with 6 Eneloops (and it was supposed to be my step-up mod), I've got a Black & Decker VPX pack sitting here and I'm ready harvest two A123 18650s from it. Hopefully these batteries will allow me to see the true potential of this bulb.

Before I put these in the light, is anyone running A123s in their 5761 without any kind of soft start and no insta flashing? The reason I ask is I spent the time to solder in a UTC (failed miserably), and was told that other's had my setup without a soft start and had not had a problem with insta flashing.

I would like to not mess with the UTC soft start if I don't have to, but I don't know if the bulb can handle the current in-rush of the A123s without it.

Thanks for your help!

-Rich

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Good Golly...Emoli!

I ordered a new Milwaukee pack for $100 on ebay yesterday. I think what I will try, as another poster did in CPF, forgot his name, is make my 4 c into a mag85 with the emoli's. This should run almost an hour on full with the AW 3 stage switch and give a nice sized light. I can also then compare side by side with my 3C a123 based 5761 light...and try the emolis in that too. I will report back in a week or so when I get this all together.

richD

p.s. I only get an open circuit voltage of 6.6v at the bulb socket with my 3c a123. The cells seem pretty consistent at 3.3v each shortly after charging. I charge them with a Trtiton Jr, not exactly designed for them..either at 4.2v/cell or now, 7.2v for 2 in series. This is the charger nominal setting...it varies a bit I think during the charge cycle. So far no issues and the run times I posted earlier with with this setup. I'm not set up to measure Vbulb under load..you guys using a shunt resistor in parallel or something? I think I saw that in here someplace.

Good Golly...Emoli!

Double post

Good Golly...Emoli!

Treble post

Re: Good Golly...Emoli!

One thing I have seen before, is people saying that the 1185 was brighter than the 5761 but have them say AH HA! after this explanation.

It can look that way and sure at the dead center that could be true! Lumens is the total light out put, the 5761 will put out more light than an 1185, if it doesn't there is something wrong with the build, now then with the science and proven technology that is no longer a varialbe.

Lux readings, (some think that is the fortune telling our friend L. Luthor does on the side) is the intensity of light at a given point, similiar to candle power designations. Usually taken dead center.

The beam patterns of the two bulbs are very different. The 1185 concentrates its light into a small hot spot. Accross the room or drive, against a wall, yep, that spot may be brighter. The 5761 throws as far but has a hot spot about twice the diameter of the 1185. There is only 50-90 lumens difference, depending on your variables between the two. You are spreading that light out over twice the area with a 5761. The total beam width is a function of the reflector, same reflector for both then only the hot spot is the issue of measurement.

Think of it this way, a hose spraying water. The amount of water, gallons/minute is equated to Lumens. The pressure is where the lumens are consentrated. Open the nozzle to a wide spray and the pressure in any area is reduced, dimmer, than making a tight stream. Same amount of water (lumens) but the feel of pressure (brightness) is different.

Yes, an 1185 can look brighter and probably is in the dead center. If you need a bright concentrated spot between these bulbs the 1185 maybe it. If you need a lot of light over a broader area or a more general use torch, the 5761 is hard to beat.

Stand in a road or field where you can compare objects and shadows out to the side for a good distance. You will see where all those little lumens are going. To light my path, the 5761 does a better job.

hmmm...sorry for the triple post...not sure how that happened

double hmmmm:-)...5761 vs 1185...you know I'm getting exactly the opposite...my 3D 1185 seems to have a larger somewhat oval beam..roughly twice the size of the 5761. At night in a dark area outside, and inside off a white wall, they seem about the same color temperature on full( I have both an AW C and D 3 stage). The 5761 has a nice round beam. Probably the reflectors..they are different..forget which..medium OP and one other(not smooth) I don't recall.

I am using a123 26650 developer cells.

richD

Re: Good Golly...Emoli!

richied said:

p.s. I only get an open circuit voltage of 6.6v at the bulb socket with my 3c a123. The cells seem pretty consistent at 3.3v each shortly after charging. I charge them with a Trtiton Jr, not exactly designed for them..either at 4.2v/cell or now, 7.2v for 2 in series. This is the charger nominal setting...it varies a bit I think during the charge cycle. So far no issues and the run times I posted earlier with with this setup. I'm not set up to measure Vbulb under load..you guys using a shunt resistor in parallel or something? I think I saw that in here someplace.

Click to expand...

On a light if you take voltage readings of the circuit along the circuit the Vbat should be the same everywhere. You did not say how you are taking the Vbulb, I would like to know what you are getting.
One thing to do is to understand what the resistance of your switch and tail cap configurations are. Measure the resistance accross each seperately. Take the bulb out and jump the socket with copper wire to remove its resistance. Some meters do not zero and you have to Tare the reading by subtracting the meter resitance from you meausurements.

Volts at the bulb is a blinding situation. Pull the bulb out a little so you can get to the pins. Put a piece of thin copper wire around each and hook to your meter. The meter is in parallel circuit now. Turn on the light an see what the reading is. That is Vbulb.

You said you are getting open circiuit readings at 6.6 volts, if you mean you are taking voltage Vbattery potential at that point I see a problem. That is if I understand what you are saying, I have mistaken things before, that is how JJ and I met!
But your batteries open circuit, no load off the charger should read about 3.6 volts, you should have 7.2 volts there. The moment you turn on the light the load pulls it down. If your open circuit is less than what you read at the batteries I would start looking for a poor connection or high resistance.

richied said:

hmmm...sorry for the triple post...not sure how that happened

double hmmmm:-)...5761 vs 1185...you know I'm getting exactly the opposite...my 3D 1185 seems to have a larger somewhat oval beam..roughly twice the size of the 5761. At night in a dark area outside, and inside off a white wall, they seem about the same color temperature on full( I have both an AW C and D 3 stage). The 5761 has a nice round beam. Probably the reflectors..they are different..forget which..medium OP and one other(not smooth) I don't recall.

I am using a123 26650 developer cells.

richD

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Yep, reflectors change things, got to be equivalent.
I prefer and for me only use smooth reflectors because they reflect the most light, as you add texture you loose light.
But to tone down the artifacts I use Armour Etch and frost the bulbs. I put it on with a cotton tip up to a point, bottom to just past the filament. The 5761s take two treatments of 35 minutes each. After the tiemis up I wash with running water, soap and a brush then finish with alcohol dabbing it off with tissue. Now that leaves the top of the bulb clear, because no shadows come from above the filament, it is the hardware below the filament that casts the artifacts and frost uses lumens whether on the reflector or glass. I squeak every last one of those guys I can out of the build.
FM reflectors and MagCharger reflectors throw a bit more than Litho 123 reflectors. Kai reflectors look like FM reflectors, I have them but have not tested them yet.
The MagCharger reflector with the 5761 can actually cast light and shadow out to over 2000 feet. The litho reflector has a very good flood effect still with 80 yards or more of very useable light for my purposes.

I will re-measure tomorrow, but what I have done is use my DVM probes inserted into the bipin bulb socket..and measure about 6.6v with the AW switch cycled to high. The batteires each measure about 3.3v after being fully charged and sitting for a while.

RichD

The reason I did the destructive testing the way I did...after much thinking, and discussion with AWR who put together the Hotrater spreadsheet....is there is no easy and reliable way to objectively test "out the front" lumen output of our lights. There is variation based on the brand, surface texture, bulb opening size, bulb focus position of the reflector. The battery brand, quality, age, state of charge, resistance of light components are hard to control. Then the size, shape, age, filament style, color of the bulb, variations in beam hotspot, smoothness, and light meter placement gives another set of variables....making objectivity nearly impossible.

I decided to treat bulbs as a point light source, and used the tube and a black background to eliminate any scatter reflections. Obviously it does not take into account the effect of bulb color on your perception, or size of hotspot/spill on practical useage. It is still useful assuming you have a reasonably similar reflector catching roughly the same overall amount of reflected light, and at least it is objective. Short of someone buying a $15,000 calibrated integrating sphere, and testing at multiple overdrive voltages for each bulb, at least twice to verify consistency....I don't see another way to compare bulbs.

Then there is the whole other issue of the dropping lux/lumen output at a particular overdrive voltage....which follows a whole other curve with the age of the bulb.

Is that the 18650s?

A123 2300mah fully charged I get a reading of 3.6v even after sitting awhile.

richied said:

I will re-measure tomorrow, but what I have done is use my DVM probes inserted into the bipin bulb socket..and measure about 6.6v with the AW switch cycled to high. The batteires each measure about 3.3v after being fully charged and sitting for a while.

RichD

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