Newbie Questions: Brinkmann 3W/3AAA Luxeon simple mod

I am in the market for a powerful helmet-mounted light and after reading about the Brinkmann 3W luxeon headlamp on this forum, I decided to get one to see if it lived up to the reviews it was getting.

The light was very bright for about an hour, but then disappointingly dimmed fairly quickly over the next couple of hours. The packaging claims up to 9 hours burn time, but my experience is the light is usable for about 1/3 to 1/2 that amount of time for bike riding.

Questions:
Can I substitute an external 2 D-cell battery pack for the internal 3-AAA-cell internal barrel without any other changes? I'd like to maximize the length of time of usable light while minimizing the necessary modifications.

Can I determine (without directly measuring) the number of milliamps driving the Luxeon? What is the "factory default" number of milliamps driving this light with 3AAA (2 in series)?

Can someone help me decode bin info on the star? Mine had this stamped on the back:
TYRJW0106128
0106LXHLLW3C
Having looked at the product binning document from Phillips, I'm more than a little confused.

Thanks in advance.

Legspeed said:

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Can I substitute an external 2 D-cell battery pack for the internal 3-AAA-cell internal barrel without any other changes? I'd like to maximize the length of time of usable light while minimizing the necessary modifications.

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Thanks in advance.

Click to expand...

Surpised no one answered this.

You can easily replace 3 AAA batteries with 3 of any other size cells, such as 3 C or D cells. As long as the voltage is the same, it will work the same, but MUCH longer. 2 D cells would not work, voltage too low.

I have the same headlamp and too am disappointed in the runtime.....although it does pretty well running a 3W off of AAA's.....

brightness is outstanding

dragoman

Use rechargeable batteries. Alkaline AAAs are really not designed for the type of drain a 3W LED draws.

You will still only get about an hour or two of use, but it will remain bright during the useful life. If the maximum brightness is not your priority, consider getting the "1W" version which is not direct drive.

You can definitely run this off of three C or D cells, for much longer runtimes.

The important letters in the bin codes are TYAJ - T means 67.2 to 87.4 lumens at 700 mA (which is the factory default for 3W Luxeons), YA ( I suspect, since there's no YR) will be fairly purplish, and J means the Vf is between 3.27 and 3.51 at 700 mA.

If you have a multimeter, you can measure the amperage pretty easily - just set the meter to the 10 or 20 Amp scale, make sure the leads are connected correctly, then touch the ground lead to the negative side of the battery pack, and the positive lead to the edge of the flashlight body. You should see something like ".70", though it may be higher due to a resistor in series.

Another thing to note: rechargeable batteries have less internal resistance than alkalines, so can drive the Luxeon a little harder. This should not be a problem if the heatsinking is decent, and on a bike, you've got airflow to help cool the head as well. Even 3 NiMH AA's in series ought to give you several hours of bright light, though that gives you the problem of recharging an odd number of cells. Most of the better chargers on the market will, but be sure to do your research first.
If you do use larger cells, make sure they've got larger capacities, and aren't just AA's in a bigger package. I've seen plenty of C and D NiMH's in stores with just 2500 mAh capacities - a true C should be 5000 or a bit more, and D's can go up to 12,000.

Best,
Jon.