P7, Buck, Boost, or Bust, Vf bins and DD sources??

[Northern Lights]

Buck or Boost, build it wrong and it is Bust. Definately a power regulating driver illiminates these problems BUT direct drive has several options for the P7.

Before anyone answers with quick simple NOOB replies, please look a little deeper this is an interesting question which has this basis:

Current P7 have FORWARD VOLTAGE bins, I and J, of 3.25-3.50 V and 3.50 to 3.75 Volts when powered at about 3.0 amps.
P7 can be DIRECT DRIVE, driven on batteries without a driver, on Lithium Ion which has a nominal (not unloaded potential of 4.2V) 3.6 volts. All the batteries sag under load BUT...
Would it not be better to drive the J bin, 3.50-3.75 FORWORD VOLTAGE with an Emoli that has 3.75 volts nominal (under 5 amp loads I have measured them at 3.8 volts!!) Li-ions are significantly lower nominal when loaded and would work best with I bin.

I am looking for someone to second my opinion that on direct drive the J bin will benefit and work well on the Emoli IMR26700 Manganese 3.7 volt, 3000 mAh battery. I believe it will be running closer to the 3.0 amps than using the 3.6 V li-ions which really sag more in voltage.

The mathematics and true application I believe must be figured on the nominal voltage not the unloaded battery potential. I have seen posts where it was assumed resting voltage was the numbers to work with. Other posts assumed the more voltage the merrier...
CPF has a wide range of experience and expertise to draw on, hence I expect things like that to pop up. Battery outputs and the resulting opinions are and sometimes not totally correct. Starting voltages on Lithium cells under load is not the same as unloaded and often is not correctly considered. As well as some Qs&As are not looking at the maximum voltage application in the manner I would analyze them.

Lithium ion batteries at 3.6 nominal voltage will power direct drive P7 emitters in both I and J Vf bins but I think the Emoli will overpower the I bin if not regulated at least with a resistor. The Emoli should be the perfect direct drive battery for the J bin. DO YOU AGREE?

Lets look deeper into this. High capacity cells that handle high C loads (C as in capacity/drain ratios) work so well that the discharge looks like a regulated graph.

Maglite SSC P7. How to. A sort of guide.
This is good, but I like the direct drive.

Good drivers are hard to find. Drivers for DIY have recieved mixed reports, and many do not exceed the 2.8 amps. Other faults have been reported. Building up drivers is a bit more work than I want to do in the next mods, especially with Direct Drive success being so very good if certain precautions are taken.

I am back into the building mode and have 3 more going on 4 P7 mod lights, The last month has seen me turn out these, Oldest started 15 months ago...
7-XRE Q5 Cree, 1600 lumen Scene Flood Light-DIY

SOLD-5761 bulb, 1331 bulb lumen, modified Maglite, Charging Jack, Electronic GI

1.5 D P7, Modes, Charging Jack, Electronic GID & more

 

[DocD]

i think i can see what your getting at, try to match the start voltage and then second the sag voltage over the length of time a battery can supply amps and the steady decrease of voltage in the battery so surely
an emoil would be better to drive a J bin but for how long it keeps 3.7volts as forward voltage ?
i think the DD of a P7 like this still would not out last a driver run time, but it would make things easy as less cost and parts to go wrong.

 

[Northern Lights]

i think i can see what your getting at, try to match the start voltage and then second the sag voltage over the length of time a battery can supply amps and the steady decrease of voltage in the battery so surely
an emoil would be better to drive a J bin but for how long it keeps 3.7volts as forward voltage ?
i think the DD of a P7 like this still would not out last a driver run time, but it would make things easy as less cost and parts to go wrong.

You got it. There is sag but the emoli meets the optimum for J bin if you are DD. Look at how many people are selling 1.5D direct drive P7s!
The reflectors are also questionable in some builds seen. The prices are $215+. I tested reflectors and you did not need meters to see that the OEM sputtered or Smooth was easily beat in luminosity and throw. I made some beauts in sputtered. They had perfect beam patterns but surprisingly because of the hype I have seen written, did not show well against the WF reflector now sold for P7 by KD and DX.
I have extra P7s, D bins I will sell this way, but wish to match the Vf with initial Vbat better.
I would supply 3 reflectors, and my specialties, charging jack and fused. Nobody else uses that forward offset charging jack.

I WOULD LOVE TO USE A 3.0 AMP DRIVER BUT THE ONLY ONES OFFERED ARE DIY AND KD. There are plenty problems posted about both. The DIY is much better but has its problems.

If anyone could suggest a solid 3.0-3.2 amp driver, please do. Only the DIY is 3.0 all other offerings are 2.8. A significant difference. DD is 3.0+ AMPS.

I took a 2.8amp MTE light and shorted the resistors and went to 3.2 amps on a 1865 and got eyeball detectable difference.

 

[vincebdx]

You got it. There is sag but the emoli meets the optimum for J bin if you are DD. Look at how many people are selling 1.5D direct drive P7s!
The reflectors are also questionable in some builds seen. The prices are $215+. I tested reflectors and you did not need meters to see that the OEM sputtered or Smooth was easily beat in luminosity and throw. I made some beauts in sputtered. They had perfect beam patterns but surprisingly because of the hype I have seen written, did not show well against the WF reflector now sold for P7 by KD and DX.
I have extra P7s, D bins I will sell this way, but wish to match the Vf with initial Vbat better.
I would supply 3 reflectors, and my specialties, charging jack and fused. Nobody else uses that forward offset charging jack.

I WOULD LOVE TO USE A 3.0 AMP DRIVER BUT THE ONLY ONES OFFERED ARE DIY AND KD. There are plenty problems posted about both. The DIY is much better but has its problems.

If anyone could suggest a solid 3.0-3.2 amp driver, please do. Only the DIY is 3.0 all other offerings are 2.8. A significant difference. DD is 3.0+ AMPS.

I took a 2.8amp MTE light and shorted the resistors and went to 3.2 amps on a 1865 and got eyeball detectable difference.

:bump:

+1
I search 3.0 A multimode board for mod my WF1000 ( 2*18650), but i dont find anything.

Please help us

 

[wquiles]

The other "important" question on your quest for a driver should be efficiency. If you have a driver giving you 75-85% efficiency, that means that 15-25% of your precious battery power is being wasted as heat.

That is one of the reasons I love the DD concept with LED's when done right - it is 100% efficient. All of the battery power reaches the LED, and if the cell's discharge rate is fairly flat/good, the dimming will not be huge to the eye.

If keeping with the idea of the DD concept, something like the D2DIM is excellent as it is still driving the LED in DD mode, but by using PWM you can effectively dim the output of the LED so that you can get more use of the light in more conditions/scenarios, etc.. Since the D2DIM is just switching an FET ON and OFF really fast, the design is inherently "very" efficient since the FET is never in linear mode

Will

 

[Northern Lights]

I fully agree. And because the Emoli and the A123 and probably the D lithium are high C batteries the discharge curves resemble driver curves, the dimming is so gradual the light is very useful. I ran out of D2Dim PWM mode regulators for the moment but that is precisely the build I like. It also looks to me, although it has not been answered, my main question, that the 3.7 Vbat of the emoli is a better choice for the D bin that is a Vf J bin LED. Although folks are awded by the output of a D or C luminous flux bin on a Li-ion of 3.6 Vbat the real performance will be had when you get the Vf up to the upper limit and again, for the J bin that is 3.7 volts.

Translates to direct drive on the Emoli from a Milwaukee tool pack.

 

[Synergic]

Yes, i also like the direct drive too.
Im going to start my second Mag P7 mod with a D bin P7.I was thinking about using 3 D size Liion protected cells from KD in series, but the driver is a problem. So finally i think ill use direct drive, using the 3 cells in parallel. Will that work?

Thanks.

 

[Northern Lights]

Yes, i also like the direct drive too.
Im going to start my second Mag P7 mod with a D bin P7.I was thinking about using 3 D size Liion protected cells from KD in series, but the driver is a problem. So finally i think ill use direct drive, using the 3 cells in parallel. Will that work?

Thanks.

Yes parallel will work and give you 3x the Ah. Do you see what I am saying however?
D luminosity bin is only offered at 3.75 Vf max, Vf is J bin
C luminosity bin is only offered at 3.50 Vf max, Vf is I bin
so if you run C on 3.6 you get more than max lumens, @ >800+ because the luminosity is figured at 2.8 amps and you are 3.0-3.2 amps.
if you run D bin on 3.6 you get less than max, @ <800 lumens or less because you are less than 2.8 amps. Best to use a 3.7 Lipo or Emoli for a D.

You must pay attention to the Vf on direct drive. With constant current drivers you get Vboost to make the 2.8 amps.
On those cells I would use a CSXOI not a DSXOJ and you would get more lumens. The D is capable of 100 lumens more but you are underpowering it.
If you use a D bin and those cells, use a driver for a minimum of 2.8 amps, 3.0 is better.

 

[phantom23]

Is there any driver to power 3xP7(series or parallel) from 2xLi-Ion (8,4V)?

 

[Synergic]

Ok i see. Bad idea for a D bin these cells....

Where can i get that emoli or lipo cells?

 

[Northern Lights]

Is there any driver to power 3xP7(series or parallel) from 2xLi-Ion (8,4V)?

yes, off course, a buck driver, that is what a driver does. The drivers available, both from DX or you can DIY from Maglite SSC P7. How to. A sort of guide. listed in Post #1
Der Wichtel makes some too.
SSC P7 Buck Converter
Read the thread and all the links and Use CPF search. It is all there. and the number of batteries or type mean nothing to the driver. It is the voltage. These are constant current drivers and generaly are buck drivers, dropping the voltage. Your Vbattery must be more than your Vforward. Look up binning and what it means under the LED manufacturers manuals. Drivers list their max and minimum voltage. Honestly, it is not hard to build these but you must understand the electronics because the answers are not simple yes, no solder here.

For one thing, you do not build good lights with LED in parallel. No two LEDs are evenly matched in power consumption so the weaker ones blow in a parallel configuration, that leaves building these in series. You need to multiply the number of LEDs by the highest voltage of the voltage range of the voltage bin, Vforward bin, listed for the now available I and J bins. For J bins it is 3x 3.75 volts is the minimum. You see you need a boost driver for 8.4 volts to get it up to the minumum voltage of 11.25 volts at the LED. I do not think there is one available.

Also if you communicate with the folks that have made 3X P7s they are impractical because of the rapid heating of the sink and then dimming of the LED. Heat is a problem, these are lights you use for a few minutes on high only.

LED modding takes some math and electronic knowledge, it is not a parts changing obsession.n

Binning, manufacterer's bin codes for luminous flux, forward Voltage, color you must understand as well as what is:
Ohms Law and how does it work
resistor values and coding
Vforward
Vbattery
Amps drawn
TjMax (not a clothing store) Thermal Junction Maximum Temperature, very important with high heat modifications like P7 and multiple LEDs.
PWM
Driver
Boost and Buck
etc.
and how to search CPF

:duh2:
and I still cannot design or build a driver.

 

[Northern Lights]

Ok i see. Bad idea for a D bin these cells....

Where can i get that emoli or lipo cells?

Fingers broke?:lolsign:
use search. and Ebay

Jim Jones may have A123s, Lux Luthor may have emoli on CPF.

The battery people are RC hobbiests. Look at www.rcgroups.com for their sources and input.:thumbsup:

 

[Northern Lights]

Well, this thread I started to see if anyone would second my presumption that the higer Vf requirement of J bin, D bin luminous flux P7s under direct drive would be better served with Lipo, emoli at 3.7 volts rather than li-ion 3.6.

I believe so. Of course a driver makes that a moot point, but direct drive it is important to overall luminous flux.

I have not got an answer but we did get into an introductory discussion about drivers.

Drivers offer modes but for a combat light it should be on/off without the problem of getting into an unwanted mode. Direct Drive allows three important things for that concept.

It will drive the P7 at about 3.0-3.2 amps which is higher than most drivers available hence brighter output.
Emolis take a high load hence their discharge curve looks like a driver is on that P7, wish I had a graph to show you but if you can extrapolate it you see what I mean.
and last, the direct drive allows use of the D2DIM which can be programed to work as press= high on.
press= off
press & hold l = high on, dim infinately.
or programed to:
Press = high on
Press and hold is high on dim in steps.

anyway it is so addressable it is fit for serious tactical use or can be programed for useful shop, outdoor activity or household uses.

 

[geek4christ]

I think I understand your point, NorthernLights. I had actually been thinking something similar, albeit not quite as thoroughly as you.

I've been thinking about a P7 build and at the time I started researching it, the best I could find were the CSXOI emitters. I thought I might just wait it out until the D bins arrived to start a build. Well they did and I found myself disappointed that they were vf bins of J for the same reason you point out -- higher vf means less lumens at a given vBatt.

I intend to run my first build direct drive as I am very new to modding and want the least complex internals possible. The thought of getting the DSWOJ running DD off 3xNiMH and having it be less bright than a CSXOI is not a very appealing one. Except for the fact that running the more efficient DSWOJ at the lower end of its luminous flux rating means it will be a little easier on the batteries and hence give longer runtimes.

Well, anyway, someone else has actually experienced just what you describe. User Mettee reports here that his D emitter is not as bright as his C emitter. Then the picture becomes a little clearer here when he informs us that he was disappointed in the DxxxJ emitter on 3s1p batteries but loved it in a 4s1p configuration. I presume he's talking about NiMH, but never got it confirmed from the source. That's the only thing that makes sense to me though, because Alkaline wouldn't be able to handle the current.

I think 3xNiMH would have a roughly equivalent nominal voltage as a single li-ion and 4xNiMH would be closer to a big emoli at that amp draw.

 

[Northern Lights]

Yes, you got it. Sometimes I wonder if I make simple things too complicated.

Yes, a direct drive on lithium 3.6 for a xxxxI P7 usually gets them up and over the 2.8 where they are rated, so if the CxxxI is rated at 2.8A to produce upt to 800 lumens you can see at 3.0+ it may very likely be up to the output of a DxxxJ at 2.8. But put that xxxxJ onto direct drive and you may acutually jump it one step in luminostity over the 2.8 rating.

Thank you for helping me explain where I was going with that.

 

[starburst]

I was about to post the question C or D bin P7 what would work the
best for a AW C cell Lion? and found this thread, look's like your all
over this NL worse than a hound on a hot coon trail.
I need to build a couple more P7's and trying to decide which VF
to get. I got some CSWOI awhile back and used DD Lion C cell and
the 2.8A driver from KD/DX . the DD C cell seem's brighter to me!!
I used the 2.8A driver with 3 NIMH just didnt seem as bright, the set
up wouldnt allow the 4th NIMH cell so I have not tried that with the
driver's, I got 2 left not sure what I want to try just yet.
I did try the Emoli cell DD with the I bin and it was obvious it was to
hot, got blue pretty fast so I scrapped that Idea. I don't have the J bin
to try but you got me thinking now. I have both A123 and Emoli cell's
If I knew for sure they would work DD using J bin I'd go ahead and order
some of those. My favorite so far is DD using the I bin VF with a single
Lion C cell. I have to agree with you on the reflector deal I have three P7's
at the moment 1st has a P7 optic narrow beam 2nd one has homemade
sputterd/stippled reflector whatever you want to call it and 3rd one has a FiveMega MOP ref. After several tries I did get a pretty good homemade reflector but that and the optic's fall short of the MOP
FiveMega reflector it's obvious there is more light off at a distance
using the MOP, and I don't really care for the SMO with the P7,
I may have to try the KD P7 reflector one of these day's
Back to VF, will the J bin do OK with the Emoli cell's? From this thread
it sound's like the J bin VF will not really be any brighter than the I bin VF
using DD Lion cell's. When using the 2.8A driver will it be better to use 4 NIMH
cell's than it would with just using 3 cell's. Sorry about the noob type
question's because I really enjoy using the P7 for about anything.

 

[Northern Lights]

The questions are the same ones I raised. So far all we have is theory to work with.
We know the drivers on DX are plublished with performance and they show a definate inefficiency and low Amps, not even getting 2.8 most of the time.
We know the OEM published specs are based on 2.8 Amps.
We know from direct readings direct driving Vf I bins on good 3.6 cells comes in starting at 3.0 Amps.
Deduction is that is brighter than what can be had on those drivers.
J bin Vf therefore will perform at 2.8 Amps as specified but direct drive that means Vf at 3.75 Volts,(the Milwaukee 26700 emoli will do that) and likely will actually do better by having a higher Amp draw.
It is 2 a.m. and I was thinking about this when the post came up. The P7 when it was born is so unconcievably bright, the next is the R2 at 228 lumens, that even underpowered with poor reflectors it was a wow to most LED enthusiasts. Truth is, many of the lights I see on the forum could do better in output.
This thread is a discussion of that. I think that the direct drive and 2.8 and less drivers that the D bin with Vf J bin are landing on are disappointing because they are powering the LED at the C bin Vf I bin optimal spec. It is a waste, in that environment the C,Vf=I will output more lumens.
But only those of the modders like you, will notice beause you need to compare and nothing compares to a P7 even if poorly powered except another P7.
The appearance of the P7 revitalized LED modding but it seems old folks and noobs both are forgetting the lessons learned on the Lumileds, remember a 60 lumen Lux III two and a half years ago was WOW!