10w RGBW using 7.2v battery packs@900 mAh

[Kyp Durron]

Is it normal for a purple saber using a 10w RGBW and a 7.2 volt battery pack@ 900 mAh to only have a 36 minute idle run time? The LED is being fully driven (R&B for purple) and the saber is pretty loud and it's wired for FoC, but that shouldn't matter as it was being timed sitting idle...

[cardcollector]

Well, in order to do the math we will need you mah rating before we can figure out this is normal.

My first instinct is to say yes though.

[Kyp Durron]

The first post stated the mAh rating, it's 900 mAh.

[cardcollector]

Is that both or one?

And what is your LED being driven at? 700ma?

[Kyp Durron]

It's a RGBW led, the red and blue are on constant while the other two dies aren't doing anything while idle, I'm not sure what current the led is being sent to the led, I'm assuming 1500 mAh as I've seen LEDEngine LED's being run at that current...actually, now that I think about it, I believe I just answered my own question assuming that it is being driven at 1500 mAh.

GOD, I really need to wake up fully before turning on the computer in the morning....

[Sunrider]

sounds about right.

[Kyp Durron]

Actually, I found out it's running the LED at 1,000 mAh, not 1500...so it really doesn't make sense to me...

[cardcollector]

Ok so your led is running two dies at 1000ma each. So that 2000 ma total, you batteries combined, if both have a rating of 900mah each, have a total of 1800mah (millilamps per hour).

So we know now you led isn't going to last an hour...
Your timed runtime is pretty darn close to the specs...

So yes, your saber should last that long.

[JamoUp]

LedEngin RGBW are rated @700ma
R= 2.24-3.20v
G= 3.68-5.12v
B= 3.20-4.16v
W= 3.20-4.16

are you wired in series or parallel? is it the same for the FoC?

[xl97]

I would think about 40+ minutes or so is correct.. with FoC and 2 dies running together..

whats the problem? are you expecting more/longer?

[FenderBender]

Ok,

LEDengins are rated minimum at 700ma. Nominal 1000ma, max (pulsed) 1500ma

That saber is running at 1A with a battery pack that says 900mah but really spec'd out at about 800mah. It is running two dice in series at 1A

Lets not forget the 1W speaker, and the CF take like 300ma to run. So you are using roughly 1300ma WITHOUT FOC.

So.....

if the batteries actually had a capacity of 1000mah, which they don't because unfortunately there are no 1000mah 14500s out there yet, Gods how I wish there were. The saber would last roughly 45-50 minutes, close to an hour with heavy pulse. Exactly what it was getting before pulse was removed, even without having 1000mah batteries. They only have a capacity of 800mah though, so you are going to only get about 61.5% of an hour with no pulse settings on the saber, hence 36 minutes give or take.

Add back in pulse settings and you'll stretch that a bit.

[Allaerra Secura]

Ok so your led is running two dies at 1000ma each. So that 2000 ma total, you batteries combined, if both have a rating of 900mah each, have a total of 1800mah (millilamps per hour).

So we know now you led isn't going to last an hour...
Your timed runtime is pretty darn close to the specs...

So yes, your saber should last that long.

No, this is not the math. The LEDs are wired in series, so they are sharing current adding voltage. So, they are using 1000 ma. The batteries are also wired in series, again sharing current adding voltage, so you get a 7.4V battery pack at 900 mah (in a perfect world, 14500s are usually less than stated).

Either way, the batteries are not going to last an hour of continuous use as the board/speaker takes approx. 300 ma (board is 3.3V speaker 1W), as Fender mentioned.

[cardcollector]

No, this is not the math. The LEDs are wired in series, so they are sharing current adding voltage. So, they are using 1000 ma. The batteries are also wired in series, again sharing current adding voltage, so you get a 7.4V battery pack at 900 mah (in a perfect world, 14500s are usually less than stated).

Either way, the batteries are not going to last an hour of continuous use as the board/speaker takes approx. 300 ma (board is 3.3V speaker 1W), as Fender mentioned.


Ah Im sorry about that. I though RGBs were wired in parallel...

My mistake:(

[FenderBender]

You can wire them in parallel, but the ramping and pulsing effects of the CF make mixed colors look UUUUUGGGLLYYY!!!!!!!!!!!! Since red takes less current than blue to run, on the lower end of a ramp or pulse the red is dominant, making it a wierd red to pink to purple kinda transition on start up and shut down as well as with pulse. However, with say the RGGB and a V5 it is actually BETTER to run the two G dice in parallel, cause you'll get the correct power to them and you won't get any kind of wierd effects on ramp/pulse. Most of the LEDengin green dice are over 4v in most bins, so wired in series and run off of 7.4 you BARELY if at all have enough Vf to run them. Wired in parallel with a 7.4V pack with the V5's capability of putting out 2A, you actually get the correct Vf and correct current to the green dice, then your FOC can be wired in series and still be run fine.

[Kyp Durron]

Ok,

LEDengins are rated minimum at 700ma. Nominal 1000ma, max (pulsed) 1500ma

That saber is running at 1A with a battery pack that says 900mah but really spec'd out at about 800mah. It is running two dice in series at 1A

Lets not forget the 1W speaker, and the CF take like 300ma to run. So you are using roughly 1300ma WITHOUT FOC.

So.....

if the batteries actually had a capacity of 1000mah, which they don't because unfortunately there are no 1000mah 14500s out there yet, Gods how I wish there were. The saber would last roughly 45-50 minutes, close to an hour with heavy pulse. Exactly what it was getting before pulse was removed, even without having 1000mah batteries. They only have a capacity of 800mah though, so you are going to only get about 61.5% of an hour with no pulse settings on the saber, hence 36 minutes give or take.

Add back in pulse settings and you'll stretch that a bit.

Ah, now that makes sense as I was only figuring 1000 mAh for the current for the LED, if I'm running 1300 already without the FoC, then the 36 minute run time makes perfect sense.


Add back in pulse settings and you'll stretch that a bit.

Nope, that's quite alright, I like the saber fine the way it is, I was just making sure that time was normal for the set up used.

[FenderBender]

Yeah, batteries are the crux of this industry (used to be switches:D). 18650s are awesome for run time and discharge rates, but it's hard to fit a 6" 18650 stick pack in a removable chassis and still get it to fit in a sub 12" hilt.;) Not impossible, but when you are also trying to fit recharge ports, LED bargraphs and recessed AV switches, the hilt real estate becomes premium. Soon though batteries will catch up to our desires and we won't have these same issues.

[Kyp Durron]

Yeah, batteries are the crux of this industry (used to be switches:D). 18650s are awesome for run time and discharge rates, but it's hard to fit a 6" 18650 stick pack in a removable chassis and still get it to fit in a sub 12" hilt.;) Not impossible, but when you are also trying to fit recharge ports, LED bargraphs and recessed AV switches, the hilt real estate becomes premium. Soon though batteries will catch up to our desires and we won't have these same issues.

And when they do catch up, I'll send my saber back to you for the upgrade, lol. The saber Qui-Gon is building for me is going to have a 14 inch hilt (I like long hilts anyways) and two 25500 Li-Ion batteries @ 3000mAh.

Granted, it won't have that unbelievable CoF, but it will have a really bright, overdriven Green Rebel LED and a really long run time. :P

[Novastar]

I just want to chime in to say... this is an *EXCELLENT* thread regarding how bloody ~important~ battery cell capacity and overall output is these days... on sabers that are (quite amazingly?) starting to draw 2A, 3A, even possibly 4A (!)... depending on how fancy the setup is.

I have a feeling that people will (soon?) be understanding why I have been lovin' on the 18650s since 2006/2007 quite easily now! I have yet to find a setup in which they are incapable of giving the performance needed.

Well... except for maybe the fact that trying to fit THREE 18650s into a hilt will be tough bogus soon enough... :D