Whats the best route for batteries with the 3W Driver?

[Ryma Mara]

I know you can stick rechargables in any of the holders and it would be just like you were using a rechargable pack but in the diagram it says for the 1W to use 4 AA's and for the 3W to use 5AA's.

Now is that regular non rechargable batteries or rechargables?

I plan on using rechargables.

Whats the voltage limit of the driver?

[Jonitus]

Are you talking about Corbin's driver? If so, then it uses PWM (pulsed-width modulation) which varies the current from high to low, and the LED "sees" the average, hence needing approximately one more volt than normal.

I think, and don't quote me on this, that Corbin has gone as high as 9 volts on the driver, but I personally wouldn't do it.

LED's are more current dependent than voltage dependent, so as long as the outputs to the LED from the board are acceptable, you should be fine with four cells in a pack. If you want to play it safe and feed the LED plenty of current, get a 6 cell pack and a resistor between the pack and the board to step it down from 7.2 volts to 6 volts. Else, since Tim is making the packs "in-house", he could probably make you a 5 cell pack if you asked nicely.

[Ryma Mara]

Yeah after all it is the only 3watt driver that I know of. :P

But yeah thanks for the info. I will just play it safe and go with the 4.2 pack. Wil make things alot easyer I think.

Thanks

[LordArgyll]

It's 5 cells, rechargeable, for 6.0V. I've run 6V through it with nary a problem. More voltage is better, because as the current drops so will the voltage, and thus the brightness. 4.2V will do okay, but I think that's just a bit below the maximum voltage for a green 3W? So your voltage drop as the batteries drain might be more noticible.

[Ryma Mara]

Oh yeah I forgot voltage and such is different from blues/greens and reds and ambers. but I plan on using a 3W amber.

[Marsupial]

There are tons of 3W drivers out there, but the 3W driver here is from corbin's specifications.

Someone correct me if I'm wrong, but his PWM driver regulates the output current to be specifically what's needed for the LED, while pulsing it. With the PWM driver you won't see a lower brightness like in battery-operated circuits - the driver will delivers the maximum brightness untill there's not ennough juice in the batts.

Also, you can get more batteries - the minimum being 1V more then what's required (otherwise you go direct current and not PWM) and the max is around 9V IIRC.

I know I drive my 1W board with 6 alcaline AA (9V) with no problems - been doing so for more then 18 months already. The battery life is incredible with that.

hope this helps.

[Ryma Mara]

BTW the driver here and corbins is the same thing

So If I understand this correctly, I could take the 7.2 Pack and not worry about supplying to much power to it then?

Cause the board will only take the power it needs and teh rest is used for insain battery life?

[Jedi Ranger]

BTW the driver here and corbins is the same thing

So If I understand this correctly, I could take the 7.2 Pack and not worry about supplying to much power to it then?

Cause the board will only take the power it needs and teh rest is used for insain battery life?

You are correct! That's (one of) the beauties of Corbin's board(s)!!

[Ryma Mara]

Well then no doute in my mind. I want one.

Thanks guys

[xwingband]

Someone correct me if I'm wrong, but his PWM driver regulates the output current to be specifically what's needed for the LED, while pulsing it. With the PWM driver you won't see a lower brightness like in battery-operated circuits - the driver will delivers the maximum brightness untill there's not ennough juice in the batts.

Correct, you won't see a gradual dimming. I have noticed a step though... and depending on the battery combo and astuteness of the observer some will too.

There is a point where the batteries can't provide the 1V juice to use the PWM, but it still is enough to light it. If you use 4.8V Ni-MH this point is harder to see, but let's say you ran a 3.7V li-ion for a Amber/Red LED you'd see it... then bam it'd die pretty quick because of the nature of li-ions.

BTW for others knowledge... the limit of Corbin's board is maybe 12V. You can use a 11.1V li-ion pack and be okay.

Also it is a neat advantage of drivers. A 6V pack will have a longer run time over a 4.8V pack if amperage is the same. The funky part is think about things like a 4.8V Ni-MH at 2200mAh vs. a 7.2V li-ion at 1400mAh.

Ni-MH have a linear voltage curve, but li-ions hold there voltage really well then die fast. Which in that combo would run longer... it's a good question! One I'm not sure of, but it should be considered.