mag 2c q5 led mod w/ coin as heatsink

[silverhare]

I decided to mod a mag 2c with a Cree XR-E Q5 Emitter on Premium Star that I got from DX.

I could have ordered a "hotlips", but I was bored so I decided to use a coin as heatsink. A swedish "5 kronor" coin. (I'm a noob after all :nana.
The coin is glued to the top with DX thermal glue.

The solder joints are probably quite bad, but it'll do for now...

As a driver I used this. According to a review at DX it should run the Q5 @ around 500mA and 3.1 V.

The led is running cool now, but I'm planning to use higher current driver @ ~700mA. Or pherhaps it can take 1000mA?

I'm not sure how this heat this "heatsink" can transfer, LOL.

Some pics:

Anyway, I'll order a mag C hotlip next time. I'm planning on a 2x18650 mag 3c mod. Any advice on drivers?

2 trustfire 18650s are ~10.5 volts (overcharged?)...

 

[Norm]

2 trustfire 18650s are ~10.5 volts (overcharged?)...

Definitely overcharged anything above 4.2 Volts per cell and you're into dangerous territory.
Please be careful overcharged lithium ion batteries are very dangerous.
Norm

 

[silverhare]

Definitely overcharged anything above 4.2 Volts per cell and you're into dangerous territory.
Please be careful overcharged lithium ion batteries are very dangerous.
Norm

According to DX they're supposed to have overcharge protection...

:thinking:

 

[EvilLithiumMan]

First and foremost, if you really have 10.5 volts on a two cell Li-Ion pack,
it's a bomb, a real bomb. I would connect a 1K ohm resistor and slowly discharge the pack to somewhere around 6.0-6.6 volts. I would then throw them away.

Second - Welcome to CPF!
Third - I think that's kind of neat using a coin as a heatsink.

But yes, you really want that Hotlips. It will get the Cree "into" the
reflector. As it is now, your hotspot is not anywhere near proper focus.

 

[silverhare]

I was wrong. It's the multimeter.The multimeter battery is running low (the low battery icon is flashing).

I'll buy a new & better multimeter tomorrow and see what it says...

 

[EvilLithiumMan]

Does your meter have a LCD display? If so, I wouldn't count it out. My experience with LCD meters and low batteries is that the display loses contrast first. Even when the LCD was barely visible, the meter reading remained steady.

 

[CM]

First and foremost, if you really have 10.5 volts on a two cell Li-Ion pack,
it's a bomb, a real bomb. I would connect a 1K ohm resistor and slowly discharge the pack to somewhere around 6.0-6.6 volts. I would then throw them away.

Second - Welcome to CPF!
Third - I think that's kind of neat using a coin as a heatsink.

But yes, you really want that Hotlips. It will get the Cree "into" the
reflector. As it is now, your hotspot is not anywhere near proper focus.

Is that a Mag 2D reflector? I didn't think the Cree would produce a good beam with it. I may have to pick up a hotlips and some Q5/R2's.

 

[EvilLithiumMan]

Is that a Mag 2D reflector? I didn't think the Cree would produce a good beam with it. I may have to pick up a hotlips and some Q5/R2's.

Mag C & D reflector are the same part, but you are right, it's a D . A 1D actually, using an AW 3300mah C Li-Ion to direct drive the Cree (no resistor). My overexposed beamshot doesn't reveal the minor "undulating lobes" that orbit the hotspot as one attemps to find the tighest focus. It is not a great beam. Nor is it a horrible beam. I guess on a scale of 0 to 10, I'd give it a 5.

I still can't get over the illusion of looking at a Mag D next to the Tiablo A9S - I'd swear the Mag has the deeper reflector. But when looking at the reflectors themselves, you can see why the A9S throws a superior, penetrating tight beam.