Please help check these parts for a P7 2D maglite build!

[Eddie-M]

I would appreciate any feedback on this build I am planning on doing! Does this combination of emitter, driver and batteries go well together???

Allready Purchased:

-2D maglite (I will not go 3D, even 2D is a bit big, I have to carry this at work)
-C bin P7
-2.8V-6.0V input P7/Cree MC-E/SST-50 driver http://www.shiningbeam.com/servlet/the-132/3-dsh-Mode-Regulated-Circuit-Board/Detail
-Universal D heatsink http://theledguy.chainreactionweb.com/index.php?cPath=48_56_73
-"Orange Peel" Aluminum Reflector
-52.1 X 1.90mm UCL Lens http://www.flashlightlens.com/str/index.php?app=ccp0&ns=prodshow&ref=ucl_lens

Battery Choices???

-4X 1/2D (1.2V NiMH & 3500MAH) http://www.batteryjunction.com/0-5-d-cell.html
-3X C cell
-fancy batteries like 123's ect

I've been trying to figure this driver thing out. Ideally the driver will be most efficient if the voltage going in is closer to the voltage going out, so I could squeeze in like 3 C batteries @ ~3.6 Volts, which is great b/c the P7 uses like ~3.5-3.6 volts at max output, but the capacity in MAH would be lower than say 4X 1/2 D batteries in all likelyhood. But then the 4X 1/2 D's are going to be running at like 4.8 Volts and the driver won't be as efficient and produces more heat right? Will this driver boost voltages? Like if I'm using 3X C batteries and thier combined voltage drops to like 3.0 volts, will the driver be able to boost it to 3.5 volts to run the P7 in the brightest mode and just suck extra amperage from the cells? I can't tell if the driver has an inductor looking at it. Ideally, what setup will aford me the most run time? At what point will the flashlite go dead (No light); is it when the voltage going to the driver dips below 2.8? Can I still operate in the brightest mode, then boom, the voltage to the driver dips below the low end threshold and all the sudden the lights go out completely?

I know these are a million questions, and in all likelyhood I'm coming across as an idiot asking the same old tired quesions. Help is appreciated, I will be doing a build log with plenty of photos (With a high quality Nikon DSLR mind you) so I'm not just a bum that will take your guys feedback without so much as a thank-you and just disapear from the forums

 

[Justin Case]

The SB driver is a linear regulator. It doesn't do any boost or buck driving.

3xC Accupower NiMH has an advertised capacity of 4500mAh. the 1/2D cells you linked are listed at only 3500mAh capacity. The 3xC NiMH will run longer. The extra voltage from 4x 1/2D is wasted by the linear regulator.

When 3xC NiMH falls out of regulation, you'll get a very long "tail" of steadily decreasing output. You should get some decent output for several hours, eventually fading down to a moonglow output that can last for a very long time. You probably should swap out the cells well before then to avoid overdischarging the cells.

How much run time do you need? If you are dead set on a 2D, then you are also somewhat locked in as to your power sources. Thus, to extend run time, reducing the drive current is probably your main option. For example, with the 3-mode driver that you linked to, you can run your light in a lower output mode. If you went with a single mode driver, then you might select a 6xAMC7135 driver (2.1A nominal drive current) instead of a 8xAMC7135 driver (2.8A nominal drive current).

If you are willing to spend more money on the build, then you can spring for a quality buck driver like a Shark Buck 3A (with or without Remora), H6CC, or hipFlex. Then run the light using 3xIMR26500 with a PVC sleeve to fit the IMRs in the DMag tube. You also will need a tail spring/tailcap mod, which is easy. See this thread for an example of a PVC sleeve and tail spring/tailcap mod. Now you will be able to take advantage of the extra voltage, since the buck driver will step down the voltage and your battery current draw will also drop proportionally.

 

[Hill]

I have the same build - 2D P7 driven DD by 3 x Accupower LSD 4500 mA cells. Very easy, dependable, and relatively cheap.

If you want a shorter body, you could cut it down and DD using 4 x AA cells or 1 x li-on (26650, 26500, 18650) to give you ~ 1 hr runtime. Plenty of links here if you search.

Good luck.

 

[PCC]

If you are willing to spend more money on the build, then you can spring for a quality buck driver like a Shark Buck 3A (with or without Remora), H6CC, or hipFlex.

I don't think the hipFlex would work because of the diameter of it. The Mag tube is smaller than the 1.4" diameter of the hipFlex. The h6Flex that's about to come out would be a good substitute as it can be turned down to 2.8 A and it will have a smaller diameter than the hipFlex.

I'm running a Kaidomain P7 driver in one of my old Mags that works pretty well. It's powered by two 18650s in a sleeve. I haven't checked the run times on it, yet, but I should be able to get around an hour on high, three hours on medium, and about 10 on low. High was measured at 500 lumens (C-bin), medium looks to me to be around 100 lumens, and low is about 50 lumens. I did not measure the medium or low power settings for output.

 

[Justin Case]

CPFers have been able to fit a hipFlex in a D Mag.

 

[alpg88]

the choise of parts is fine imo, i'd go with 3 c lsd nimh cells.

if size matters, why don't you go with 2c, buck driver, and 2 18650 cells?

glass lens isn't necessary, plastic will do just fine, neither is aluminium reflector, plastic one will be just fine too,

 

[irv_usc]

why not a p7 specific heatsink, like H22a or britelumens?

if you are thinking of 3nimh, would you consider direct drive?

 

[Eddie-M]

The SB driver is a linear regulator. It doesn't do any boost or buck driving.

3xC Accupower NiMH has an advertised capacity of 4500mAh. the 1/2D cells you linked are listed at only 3500mAh capacity. The 3xC NiMH will run longer. The extra voltage from 4x 1/2D is wasted by the linear regulator.

When 3xC NiMH falls out of regulation, you'll get a very long "tail" of steadily decreasing output. You should get some decent output for several hours, eventually fading down to a moonglow output that can last for a very long time. You probably should swap out the cells well before then to avoid overdischarging the cells.

How much run time do you need? If you are dead set on a 2D, then you are also somewhat locked in as to your power sources. Thus, to extend run time, reducing the drive current is probably your main option. For example, with the 3-mode driver that you linked to, you can run your light in a lower output mode. If you went with a single mode driver, then you might select a 6xAMC7135 driver (2.1A nominal drive current) instead of a 8xAMC7135 driver (2.8A nominal drive current).

If you are willing to spend more money on the build, then you can spring for a quality buck driver like a Shark Buck 3A (with or without Remora), H6CC, or hipFlex. Then run the light using 3xIMR26500 with a PVC sleeve to fit the IMRs in the DMag tube. You also will need a tail spring/tailcap mod, which is easy. See this thread for an example of a PVC sleeve and tail spring/tailcap mod. Now you will be able to take advantage of the extra voltage, since the buck driver will step down the voltage and your battery current draw will also drop proportionally.

Thanks for the feedback.

Ok, I just read the wiki article on a linear regulator which brings up a few more questions. In my case, any voltage above 3.6 going into the regulator will be turned into heat, so 4X 1/2D will just get regulated from 4.8 to 3.6 by the extra voltage being turned into heat. Even so, since it will take a longer time for 4.8 volts to drop below 3.6 as the batteries discharge, wouldent I still be able to run the driver in high mode (2.8A X 3.6V) longer than if I had 3X C batteries, since they would start at 3.6V and quickly drop below that?

This linear regulator is rated at 2.8-6V, so I take it that 2.8V must be the low end for the regulator to be able to maintain constant wattage in its low light mode (0.140A X 2.8V). If I am running in low light mode and the driver is reducing the voltage going out to the LED to 2.8V from say 3.6V going into it from a set of 3X C batteries, am I still using the same amount of power as if I had it in high mode with 3.6V going out to the LED? Pretty much I'm asking if any of the medium or low modes of the regulator will extend battery life, or if the regulator still always draws the same power and just converts the extra wattage into heat through resistors vs going to the LED.

Part of the reason I like this driver is the 3 light modes, but if they all just acheive that by turning power into heat and it doesn't gain me any battery life, then its pointless and I should just run the thing on high all the time.

 

[Eddie-M]

I have the same build - 2D P7 driven DD by 3 x Accupower LSD 4500 mA cells. Very easy, dependable, and relatively cheap.

If you want a shorter body, you could cut it down and DD using 4 x AA cells or 1 x li-on (26650, 26500, 18650) to give you ~ 1 hr runtime. Plenty of links here if you search.

Good luck.

Thanks. I didn't want to use direct drive it b/c I want to have the P7 driven at the full 3.6Volts for a long while so even if I use the flashlight with less than full cells, I can still have the most pottential light output with 2.8Amps X 3.6Volts at the P7. With direct drive I would only be at the 3.6V for a short while until the batteries started to discharge. Plus I wanted the Hi/Med/Low modes.

Not sure about making a 1D, I want to be able to swap the guts of this flashlight into a new maglite body easily if this one gets too banged up.

 

[Eddie-M]

the choise of parts is fine imo, i'd go with 3 c lsd nimh cells.

if size matters, why don't you go with 2c, buck driver, and 2 18650 cells?

glass lens isn't necessary, plastic will do just fine, neither is aluminium reflector, plastic one will be just fine too,

I wanted a little more capicity than a 2C, so I chose the 2D initially. I didn't want a 3D at all though.

I bought the lens for better optic clarity and cosmetics, and the reflector to avoide the hole in the middle of the hot spot by having the orange peel texture, and again cosmetics.

why not a p7 specific heatsink, like H22a or britelumens?

if you are thinking of 3nimh, would you consider direct drive?

I bought this P7 b/c I knew the star base or whatever it's called would be electrically insulated from the heatsink. The P7 w/o the star base was not as bright and could short to the heatsink. The maglite heatsink I ordered looks to be totally smooth so This should glue to it easily, just have to make sure I center it well.

 

[PCC]

CPFers have been able to fit a hipFlex in a D Mag.

Really? Without boring the Mag or cutting down the hipFlex? I never got around to buying a hipFlex and when George announced the h6Flex I figured I go with that one instead because of the potential for more power to use with Luminous emitters and the smaller form factor.

 

[Nil Einne]

Thanks. I didn't want to use direct drive it b/c I want to have the P7 driven at the full 3.6Volts for a long while so even if I use the flashlight with less than full cells, I can still have the most pottential light output with 2.8Amps X 3.6Volts at the P7. With direct drive I would only be at the 3.6V for a short while until the batteries started to discharge. Plus I wanted the Hi/Med/Low modes.

Not sure about making a 1D, I want to be able to swap the guts of this flashlight into a new maglite body easily if this one gets too banged up.

There are plenty of people who know more about this then me who will hopefully correct me if I'm wrong. But a look at sku 1217 on SB suggests to me it's just an AMC7135 based linear regulator board confirmed by http://www.videofoundry.co.nz/ianman/laboratory/research/driverlist.php As I understand it, this means you're never going to do better then under DD, it's not a boost driver. If you can only manage 2.8A with fresh cells the driver isn't going maintain output when voltage drops (well it may maintain it at a lower level, particularly if you remove some of the AMC7135 chips), in fact if anything it may be slightly worse. http://www.videofoundry.co.nz/ianman/laboratory/research/driverlist.php#AMC7135 and http://www.candlepowerforums.com/vb/showthread.php?t=247543 may be useful

If you're likely to be using a variety of different cells, some of which may provide more volts, using a driver will be good to protect the LED but otherwise sticking with DD would be a good idea I think. One option would be to buy the LED first and test the Vf or see what it draws under DD with your fresh cells. If it's close to 2.8A using a linear regulator or buck driver won't help maintain brightness (well except brightness at a lower level if that's what you desire).

As for the modes, I think you can add modes under DD (basically use PWM for modes but without any regulator) but that's getting a bit beyond my realm of knowledge.

 

[jcvjcvjcvjcv]

I'd opt for the 3xC

I run a P7 CxxxI on three AccuPower D cells in a 3D (DirectDrive), so 3xC should be fine too. Just 45% of the runtime. And a whole lot less weight. My 3D P7 DD is around 880 gram.

 

[Eddie-M]

OP Here. Thanks for the input guys. Turns out I'm building 4 maglites now!

-2D with C bin P7 run with 2X 1D-3AA converters from KD wired in parallel & Shining Beam linear regulator
-3D with C bin P7 run with 3X D NiMh & Shining Beam linear regulator

-2D with P7 DSWOJ emitter, Der Witchtel 6 mode buck driver & Fivemegas 2D-6AA converter
-4D with 3X P7 DSWOJ emitter, Der Witchtel 3X P7 kit with 6 mode buck driver & Fivemegas 4D-12AA converter

The first two are with the C bin p7's from Deal Extreme and I will probably give one to my brother and one to the girlfriends dad.

The second two get the ultraclear lens treatment and aluminum reflector for the single P7 as well as eneloops and Fivemegas battery adapters. Those will be my personal awesome lights.

I'll try to make a build log pretty soon :thumbsup: