What is the max current I can expect from -

[wtraymond]

I just bought a BB1000 Nexgen from the Shoppe with the intent of running it on a AA lithium, but I don't expect a single AA Li-ion or a 123 will provide that much current alone.

How much max current should I expect from single AA Li-ion, CR123, R123, AA NiMH, AA NiCD, and AA Alkaline?

Will the BB1000 be less efficient than a BB750 at driving a Lux III off one cell? /ubbthreads/images/graemlins/confused.gif

 

[srue]

I can tell you right now that a single AA NiMH/NiCD/Alkaline/Lithium will not run a NexGen BadBoy, especially at a high current such as 750 or 1000mA.

I also want to make clear the difference between an AA Lithium and an AA Li-ion. Energizer makes some Lithium AA batteries that run at 1.7V and are generally better than Alkalines. They are not rechargeable. Li-ion batteries of any size/shape run at 3.6V nominally (4.2V starting voltage) and are rechargeable. Not only can the Li-ion chemistry provide decent currents, but the higher starting voltage means the converter doesn't have to tax the battery as much.

Li-ion (whether it be AA or R123) is pretty much your only bet for running a NG1000 at full capacity. A CR123 will probably only enable "safe mode," which I think is something like 750mA.

 

[AuroraLite]

Hi, Wtraymond.

Not an EE person, but I will give it a shot from what little I know:

As far as I know, unlike the MM lite, the BB NG could not be runned by one normal AA cell only(Alkaline, Nimh, Nicd)

It probably should run fine on CR 123 and AA li-ion(if V of it is 3V), I am not sure about R123.

BB NG 1A is to provide 1A of current to the Lux, but in order to maintain that current regulation, it might have to pull more than 1A from the batterie(s).

And since there is a high current, the voltage of those batteries(especially alkaline) will not hold up well aganist the high current; which in turn will also mean the BBNG will drop into it's safe mode sooner(shorter regulation time)

Personally, I have and used BBNG 500 and 750 for minimag sandwich(and 1A for PM6 mod), and I think there is for sure some noticeable diminishing return here for increasing the current like that.

A user might experience much shorter runtime(from 500 > 750 with same bin Lux III, my experiment had shown about 30% less runtime), in trade for not very obivious gain of light by naked eyes(I would say the preceived increment will be 10-20% from the same reflector, again same bin).

For powering by 1AA, and if you desire some degree of brightness, I would suggest Madmax+(~700ma?) for Minimag setting; MM+/MM/maybe a BBNG 1A for single CR123 battery. And Madmax series, from my understanding, seems to be more 'effcient' since it will suck the batteries drier.

Hope this helps! /ubbthreads/images/graemlins/smile.gif

 

[AuroraLite]

Haha...Srue! You'd bet me to the answering, good job! /ubbthreads/images/graemlins/grin.gif

 

[wtraymond]

I guess I misspoke in that I said lithium when I meant Li-ion. I intended to use one Li-ion AA which would provide about 3.7v or maybe an R123, or Pila cell. All would provide me with the necessary starting voltage to drive the BB.

But since I was asking, I also was curious about what kind of max current each single cell would give if I were to use two or more of a different cell type (eg. NiMH, NiCD, alk...)

I'm guessing that I'll get ~700ma max out of a AA Li-ion. Will a R123 provide more current than the Li-ion AA or just more capacity? Would the BB750 config do a better job than the BB1000 since the max current is only ~700 anyway?

 

[greenLED]

Auroralite, you mention the converter would need to pull more current off the battery when running at 1000mA. How is this additional current related to the efficiency of a circuit. If a circuit was, say, 80% efficient, does this mean that it has to pull 1200 mA from the battery? I'm not sure if I explained my self properly.
...
...
Rephrasing: How much extra current does a circuit need to pull if its efficiency is 80% and it runs at 1000 mA. (or any other set of efficiency and current). Are efficiency and this additional current even related? /ubbthreads/images/graemlins/icon3.gif

I'm trying to learn this EE stuff. Thanks!! /ubbthreads/images/graemlins/thumbsup.gif

 

[AuroraLite]

Hi, Greenled!

Hope I'd have straight answer for you, but unfortunately I am hardly an EE person and my knowledge is based on what I read and experiment with what I had. /ubbthreads/images/graemlins/blush.gif

From posts here:
Safe Mode and Full Mode for NGs
NextGen BadBoy, when?

are where I had learned some very basic ideas as how BB and BB NG works, it seems to me that BB NG is 'better' than BB because of its efficiency, where it will not 'suck' the battery as hard to make the regulation. Thus, it probably will allow longer runtime and less heat generated.

And as Srue puts it(which Wayne had also mentioned in his post), 1A with CR123 will probably always start in 'safe mode'--

The magic equation is(from Wayne):

Full regulation when:
1A * Vin <= Vf * ILED

The 'average' of J bin Lux III has the Vf of 3.4v(which worst case scenario is 3.51v)

By the equation, we then know that for 1A current supplied to Lux III(Iin = 1A), the Vin will have to be 3.4 to stay regulated.

I don't know exactly how much voltage drop for various batteries, but from those posts, it states that for BB board, 123 will drop 0.5v when 1A is being drawn from it. /ubbthreads/images/graemlins/icon15.gif

Hope this helps. /ubbthreads/images/graemlins/smile.gif

 

[srue]

[ QUOTE ]
wtraymond said:
I'm guessing that I'll get ~700ma max out of a AA Li-ion. Will a R123 provide more current than the Li-ion AA or just more capacity? Would the BB750 config do a better job than the BB1000 since the max current is only ~700 anyway?

[/ QUOTE ]

An AA battery is actually about the same volume as a CR123, and since capacity and ability to provide high current are roughly analogous to volume, a li-ion AA should perform similarly to a li-ion 123.

My guess is that both types would adequately handle a NG1000, but a NG750 would be a safe bet. CPF motto: get both.

 

[wtraymond]

Well, the links worked great for shedding a little... well you know. Thanks AuroraLite.

It appears the NG1000 I bought will work great on one Li-ion AA or R123 albeit a very short time. Maybe about 30min if left on. But it seems that the K binned Luxs I bought will be cutting it close on start up voltage for full regulation. I may have to buy a J binned Lux.

The BB (and NG BB) will NEVER drop into safe mode from full-regulated until you turn power off and then back on. When you turn your light on and the battery voltage is enough for full regulation, that light will burn with a full-regulated (constant current) output until battery voltage drops below ~1.8v. At that point useable light is gone.

The BB doesn't suck the batteries any drier than the NG but it does suck them down faster. The NG boards are ~5% more efficient and draw less current from the batteries to drive the Lux at a constant current. Less current draw from the batteries keeps the battery voltage higher for a longer time. THe higher battery voltage makes it easier for that battery to deliver the current (eg. If you put a 1000mA load on a fresh 3.7V Li-ion battery, its voltage will immediately drop ~.5v to ~3.2v. If you put a 750mA load on the same freshly charged battery, its voltage will only drop ~.3v to ~3.4v)

The efficiency of the Badboy and NexGen is a percentage of current drawn from the battery that is delivered to the emitter. The rating of each board (ie. BB400, BB500, BB750...) is the approximate current regulated output to the emmitter in full regulation mode.

I think I've answered all my own questions to this point. You've all been very helpful.

 

[AuroraLite]

[ QUOTE ]
wtraymond said:

The BB (and NG BB) will NEVER drop into safe mode from full-regulated until you turn power off and then back on. When you turn your light on and the battery voltage is enough for full regulation, that light will burn with a full-regulated (constant current) output until battery voltage drops below ~1.8v. At that point useable light is gone.


[/ QUOTE ]

From my little own runtime experiment, I actually think it might drop into a 'moon' mode whenever the Vin is lower than that 'magic threshold'(from the equation above). I had taken pictures from a BBNG 500, BBNG750, with a Madmax(only on when picture is taken) at every ~10 minutes with the same exposure and focus.

The result is a very obvious drop of light output(30% of the 'regulated brightness' or less from naked eyes) around 50 minutes for BBNG750, and around 90 minutes, the drop occured for BBNG500. And then that 'moon mode' just last forever, and it gradually dim ever so slowly for hours(I cut off the experinment a few hours afterwards.)

So you are definitely correct that, for the Nth time you turn on the light, if there is enough Vin(above threshold), then there is regulation. But it would probably still drop out of regulation(entering the moon mode?) if the threshold is crossed.

The 1.8v number is probably a good estimation for the Lux III J bin, BBNG 500 'magic threshold' Vin in order for it to stay in regulation--

From the equation,
Full regulation if,
1A * Vin <= 3.4v * 0.5A
Vin = 1.7

And as for BBNG 1A, full regulation will fail when the Vin is below 3.4v.

Good luck with your setup! /ubbthreads/images/graemlins/smile.gif

 

[greenLED]

Thanks for the linkies, Aurora! I've totally ignored the NG converter.

 

[AuroraLite]

Greenled: Don't mention it /ubbthreads/images/graemlins/blush.gif

Btw, I mistakenly wrote the output drop from naked eyes are '30% or less', but what I actually mean is it dropped to '30% of the regulated brightness or less'. Post edited. /ubbthreads/images/graemlins/icon15.gif /ubbthreads/images/graemlins/smile.gif