Powering all Tri-Cree LEDs at once? Requirements?

[Dogo]

If I wanted to power all three LEDs in a Tri-Cree at once (All Blue) for a stunt saber with a recharge port, would I need three Lithium Ion batteries to power three ? What would the requirements be for that? And is this a dumb question?


Also, would each LED need its own resistor?

[phook15]

I would use a single 3.7 volt 3400 mAh battery, and wire the leds in parallel(running the positive wire to the leds, spitting it up to the three die). You could add a 1 ohm 2 watt resistor for each led or one resistor and split the wire off to all the led pads. You also might not need a resistor because you won't have a soundboard, but I would use them to save power. You are using the 3.47 volt blue leds?

[FenixFire]

I would use a single 3.7 volt 3400 mAh battery, and wire the leds in parallel(running the positive wire to the leds, spitting it up to the three die). You could add a 1 ohm 2 watt resistor for each led or one resistor and split the wire off to all the led pads. You also might not need a resistor because you won't have a soundboard, but I would use them to save power. You are using the 3.47 volt blue leds?

The resistors wont save you power, they protect the LEDs from over driving beyond their capability. Resistors actually dissipate the excess voltage as heat (the Wattage rating). There are several ways to wire the system you want depending on what you want to spend and what components you have access to at the moment, such as a buckpuck with a 7.4v battery. Technically no 1 resistor for all leds would work, but the chance of a runaway voltage condition increases. It is safer to use one resistor per LED.

[Greenie]

I have to concur with FenixFire, 7.4v and a buck puck would be my choice for a tri led stunt saber.

[Dogo]

So I'd be looking at a buckpuck, three resistors and a 7.4v?

Also, how long of a battery life would I be looking at? A much more vague question, I know, but a ballpark in increments of 10 or 15 minutes would be helpful.

[NanoRex]

I have to concur with FenixFire, 7.4v and a buck puck would be my choice for a tri led stunt saber.

How would one wire this up with 3 LEDs?

[FenixFire]

So I'd be looking at a buckpuck, three resistors and a 7.4v?

Also, how long of a battery life would I be looking at? A much more vague question, I know, but a ballpark in increments of 10 or 15 minutes would be helpful.

No resistors needed when using the buckpuck. The purpose of the puck is to regulate the current.

[Forgetful Jedi Knight]

No resistors needed when using the buckpuck. The purpose of the puck is to regulate the current.

1 Amp divided by 3 dice? I don't see that ending real well.

[Silver Serpent]

If you insist on using a buckpuck with a B/B/B LED, the best solution is to wire all three dice in series, and use a 3-cell li-ion pack.
You could also use 2 dice in series with the buckpuck and a 2-cell pack, and then wire up the third die by itself with a resistor.

Honestly, personally I'd build it the way phook15 stated. A single li-ion, and all three dice wired in parallel with their own resistor.

[Richei Blasto]

I'm still trying to figure all this out myself, so I'll post my understanding of the 2 options discussed above to drive all 3 LEDs at full brightness, and would be grateful if someone would point out any mistakes! I certainly don't want to give Dogo (or others) any incorrect information based on my limited research so far...

Option 1 - 1x 3.7 volt li-ion 3400 mAh battery (the higher mAh the better as each die will want to draw 1000ma for 3A total, but be aware of fake ratings, such as many claiming 5000 or 6000mAh), and running the 3 dies in parallel each with their own resistor - as recommended above. While some have found you can run a 3.47v LED from 3.7v battery without a resistor, others say that because these batteries are at 4.2v when fully charged (the 3.7v rating is the average voltage) resistors are cheap but valuable insurance.

Pros: cheap, simple, takes up little space. Cons: short battery life - could use 2 or more batteries in parallel, recharge port etc.

Option 2 - TCSS 1000ma BuckPuck http://www.thecustomsabershop.com/Bu...wire-P364.aspx. A BuckPuck is a current regulator, so it will pump out the advertised current over a range of voltages (5v - 32v in this case). So if your LED is happy with 1000ma, this is what you'll get from the BuckPuck as long as you're putting in at least 1.5v above the LED's forward voltage - it will run safely and reliably at max brightness. No resistors are needed because they are only used here for quick and dirty current regulation, and the Buck Puck is designed to do that job.

But the 5v min won't pump enough 'juice' into the BuckPuck for more than 1 x 1000ma die. The link says to use around 8v for 2 dies and around 12v for all 3. As long as the LEDs are getting their 1000ma at above their forward voltage, they don't care about the voltage going into the BuckPuck. You'd wire these in series rather than parallel, and of course they're still drawing a total of 3A, just like in Option 1.

So, the question becomes how best to get 12v-15v into the BuckPuch to get them to full brightness. 4 x 3.7v Li = 14.8v would seem perfect, except that fully charged you've got 16.8v - I don't know how much of a problem this would be given the 15v max rating, but you could always use a voltage regulator (or a resistor!) for insurance. 3 x 3.7v Li is 12.6v fully charged, so that's good, but at their average voltage you're only looking at 11.1v, so you might not be getting every little bit of brightness out. Of course you might get better numbers using Ni-mh or vanilla alkalines etc.

Pros: Much longer battery life using 3+ batteries for about 12v than using one battery per Option 1. Cons: More expensive, takes up more space.

I hope I got this right, but would welcome your feedback.

Rich