GD or BBNG for SSC P4 2C Maglite mod?

I have a 2C Maglite laying around that I'd like to bring into the 21st century. It is a "C" serial numbered Mag, purchased around 2003.

Any reason to favor the GD or BBNG board as the driver for an SSC P4 U2SW0H-bin mod of a 2C Maglite? I plan to use the usual 4Sevens, LiteMania, etc heat sink.

How would the selection of the GD vs BBNG be affected by the following potential battery configurations:

- 2xC-Alkaline (or D, if my 2C Maglite is too "weak")
- 2xAA Eneloops in the Eneloop C-cell adapters (or D adapters)
- 2xC-NiMH (or D; I don't have any either of these sized NiMH cells, so I would have to buy some and also get a charger for them)

Has anyone tried to drive the SSC P4 at 1000ma in full regulation with a GD or BBNG in a 2-cell Maglite? Should I abandon that drive current and go with something like 750ma? I tried doing a CPF search, but the results seemed to be all over the map. Some posts simply suggested "use a GD1000", or "use a BB1000", etc. But it was never clear that people made any measurements to show that those boards actually ran in full regulation and delivered 1000ma to the LED.

Thanks.

I would recommend the BBNG. It is more efficient.

As long as you are never planning on putting in a battery configuration where the battery voltage is greater than 3.5V like a single li-ion cell.

All the batteries you listed meet the BBNG for a boost configuration.

Wayne

This post seems to suggest that 2.7V might be around the lower limit for full regulation for a GD1000. No statement as to the host flashlight.

For 4xAA, this thread seems pretty definitive that an SOB1000 is the way to go. For 3xC-cells, a GD1000 looks fine.

This thread has claims that the GD1000 is the way to go for 2xNiMH, but I don't see any statements regarding actual implementation.

The OP in this thread asks essentially the same question as I am asking, but there doesn't seem to be any resolution to the issue.

So the 2xNiMH/Alkaline configuration seems to be the hazy case.

I seemed to have good results using a BBNG1000 to drive an SSC P4 U2SW0H-bin mounted on an AW tower and inserted into a SureFire TurboHead (SureFire 6P body). Power source was 1xLi-ion. I passed the AW tower to another fellow who said it works great when driven by 2xC-alkalines. Unfortunately, I don't have any hard data on lux output, current draw, run time, etc with the 2xC-alkalines.

But a SureFire isn't a Maglite, so I don't know if this same driver/LED configuration would work well in a 2-cell Mag. Unfortunately, it's a C-Mag, otherwise I would consider getting one of those 2D->6AA battery holders and avoid the whole issue.

dat2zip said:

I would recommend the BBNG. It is more efficient.

As long as you are never planning on putting in a battery configuration where the battery voltage is greater than 3.5V like a single li-ion cell.

All the batteries you listed meet the BBNG for a boost configuration.

Wayne

Click to expand...

All right! It looks like I'm going to spend some more money on a BBNG1000.

dat2zip said:

As long as you are never planning on putting in a battery configuration where the battery voltage is greater than 3.5V like a single li-ion cell.

Click to expand...

I don't understand this. Did Wayne mention the BBNG can be used with 1xLi-Ion
https://www.candlepowerforums.com/threads/223348 (post 14)

yazkaz,

From the other thread. That person only wanted to use alkaline and NiCD/NiMH batteries.

In that case the BBNG would always be in boost mode. Using a li-ion with a BBNG could put the converter in situation where the battery voltage is higher than the VF of the LED and risk overdriving the LED.

Maybe, I should have worded it "your are fine as long as you don't use a li-ion type battery...".

Wayne

I just had a crazy idea. Instead of using an SSC P4 U2SW0H-bin, how about a Cree MC-E in 4P? Underdriving it with a BBNG1000 should give a really low Vf, yet still provide at least the same amount of lumens, if not more, compared to the P4.

You may want one or the other LED. The MCE has a larger die footprint and would thus give you a less focused beam as compared to a single die LED.

Wayne

I've noticed the different beam focus when using a P4 vs MC-E in 2.5" SureFure TurboHeads. The MC-E still gives a pretty good hot spot, comparable to a Q5 or R2 drop-in for the SureFire 6P series.

This series of beamshots from StefanFS shows that the MC-E and the P7 also perform pretty well for throw and flood in a Mag.

What attracted me to the idea of using an MC-E (or even a P7) is that at the low drive current, the calculated Vf for the MC-E is about 3.1V. For the P7, about 3.25V (I voltage bin). In comparison, the P4 U2xxxH-bin calculates out to about 3.5V.

I decided to stick with the plan and I built my 2C Mag mod using an SSC P4 U2SW0H-bin LED and the BBNG 1000. It's an easy mod that brings my old Mag up to modern specs. The light had languished in a closet for years.

Performance is quite satisfactory. Beam pattern is surprisingly good using the stock reflector once I twiddled the Mag head to get the best focus. The pattern is actually quite similar to the pattern I get using an SSC P4-based AW Turbo Tower in a SureFire TurboHead. The Mag runs on both 2xC alkalines and 2xAA Eneloops.

Heat sink with P4 inside of the 2C Mag. I removed the bezel ring and the reflector (they are seen in the background).


Reflector view of the P4.


Donut hole beam pattern before focusing (Mag head was screwed down all the way). Distance to the wall is about 6 feet. EV set to -2.


Beam pattern after focusing (edge of the reflector hole about level with the top of the heat sink pedestal). EV -1. Note the thin, bright ring in the spill. That's really the only noticeable beam defect.


Lighting up the basement stairs (pitch black otherwise).

It is my understanding that three 4/5 sub-C NiMH cells have the same overall length as two regular C cells. Is it safe to run the BBNG1000 with 3 of these NiMH cells to drive a Seoul p4 U2SW0H-bin LED in the 2C Mag? Nominal voltage would be 3.6V, but hot off the charger I can envision an initial 4.2V for some "brief" period.