1x14500 + AMC7135's + MC-E??

[ti-force]

I'd like to run an MC-E emitter with 7135's using 1-AW 14500 battery. How many 7135's will this battery support? I probably won't be able to run the light very long because of a lack of enough heat sinking, but what are the possibilities for a pocket rocket being used for short bursts, with these materials? What do you guys think?

Casey

 

[LEDninja]

1*14500 is ~700 mAH. Max current should be <2C or <2*700mAH or <1400 mAH. To give yourself a safety margin maybe max out at 1000 mAH.

 

[The Dane]

Even a 18650 or 26650 cant hold up to 3.7V 2.8A for any length of time!
So 7135's are a waste of money! If you get 750-1000mA under load (4W) consier yourself lucky!

 

[ti-force]

1*14500 is ~700 mAH. Max current should be <2C or <2*700mAH or <1400 mAH. To give yourself a safety margin maybe max out at 1000 mAH.

Well, that's not as much fun as I thought it would be. I knew their was a maximum "safe" discharge rate, I just didn't know how much. Thanks for clearing that up for me. I'm guessing that 2c is the general rule of thumb for li-ion batteries? Does anyone make a 14500 size battery (non- li-ion) with a higher discharge rate?

I think I'll save the MC-E for an 18650 light, because I could probably get better results out of an XP-G r5 or XP-E r2 at 1A than an MC-E at 1A, couldn't I?

Would it be safe to drive an XP-G r5 at 1.3A for short bursts?

Thanks for your time.

 

[ti-force]

Even a 18650 or 26650 cant hold up to 3.7V 2.8A for any length of time!
So 7135's are a waste of money! If you get 750-1000mA under load (4W) consier yourself lucky!

What drivers do you suggest running? Must be 17mm or smaller.

 

[Linger]

So 7135's are a waste of money!

Dissenting opinion: a single 7135 will put through a max 300-350ma. Lower levels are usually achieved through a controller which uses Pulse Width Modulation (thruning the 7135's on and off at a very fast rate). In that they are among the most efficient regulators dropping a higher vbat to a more appropriate led vf.
Some popular drivers include multiple 7135's to combine the output creating a higher max. For example, a 3mode driver with 3x7135 with 1050ma max. Or the 8x7135 for a possible 2.5-2.8A max.
As The Dane correctly advises, many batteries will not maintain a high output. I recently ran through my 18650's and found some brands wouldn't break 1.5A even on high (theoretically 2.8A), while other more expensive batteries pushed 2A, and the highest did give 2.8A

So the original question, how many for an mc-e driven by 14500. The answer is this isn't a good combination. The mc-e will work of course, but you'll have a lot of reserve capacity with it. If you're short on emitters, allocating the mc-e to a better powered unit is an option. You could try 1amp and get a decent volume of light, but you could also use one of the new K2's,a U3 binned souel P4 or an xpg at 1A.
I'm not sure what you mean by poor heat-sinking - if the emitter is well connected to the body of a metal flashlight, hold it in your hand and you'll pull a lot of heat off it into you body.
Of course if you're looking for a pocket rocket does it have to be practical? You could try a self-destructable light with 1750ma or 2100ma driver with 3 modes and a 'burst' that is totally impractical and going to ruin your battery life, melt the torch if acidentally left on on high, but is also one heck of an impressive little rocket. *odds are tailcap measures won't reach the 2.1A theoretically permitted by the driver:I suspect because of too much internal resistance in the cell

Best,
Linger

 

[ifor powell]

My home made running headlight has 2 XPG's in parralel and a custom linear regulator. I can run it at 1500ma with a 14500 but I do not normaly push it that hard. The voltages sags quickly and it drops out of regulation. At 1000ma it stays in regulation well with a 14500 cell so I think that's about the limit for good regulation.

my previous design was an MCE but I never tried that with a 14500 only 18650 cells. It's been retired now as the new light is considerably more efficent and lighter with the 14500. If I want more output I can use an 18650 and get 2000ma which is as good as the old MCE light at max.

Ifor

 

[ti-force]

I recently ran through my 18650's and found some brands wouldn't break 1.5A even on high (theoretically 2.8A), while other more expensive batteries pushed 2A, and the highest did give 2.8A

By more expensive batteries, do you mean AW's?

I'm not sure what you mean by poor heat-sinking - if the emitter is well connected to the body of a metal flashlight, hold it in your hand and you'll pull a lot of heat off it into you body.

I'm glad you mentioned this. I wasn't really taking that into account, and no longer than I'll run this light on high, that should work great.

Of course if you're looking for a pocket rocket does it have to be practical? You could try a self-destructable light with 1750ma or 2100ma driver with 3 modes and a 'burst' that is totally impractical and going to ruin your battery life, melt the torch if acidentally left on on high, but is also one heck of an impressive little rocket. *odds are tailcap measures won't reach the 2.1A theoretically permitted by the driver:I suspect because of too much internal resistance in the cell

:devil:.......:devil:................... :thumbsup: I like the way your thinking here. That's exactly what I had in mind.

Of course, I'll be extremely carefull not to leave it on high for too long.

 

[Linger]

By more expensive batteries, do you mean AW's?

yeah, and IMR produced the highest output. The Eagletac 18650 also did well. iirc flame graphic trustfire did OK, blue trustfire, blue unlabeled included with Solarforce lowest.

re: hand heatsink - I'm glad you mentioned this. I wasn't really taking that into account
just so you're warned, you must be an advanced user to do this. you make your light inherently unsafe:accidental activation or child/friend playing with it could be fatal? (in addition to frying the driver, destroying emitter, excessive heat may lead to batteries venting with flame)

:devil:.......:devil:...................:thumbsup: I like the way your thinking here. That is exactly what I had in mind. Of course, I'll be extremely carefull not to leave it on high for too long
It can be a great trick. Batteries will tolerate a burst discharge. Especially useful under/behind objects in otherwise brightly lit rooms. I find a few seconds is all I need to scope the terrain and confirm suspected detail, afterwards i'm happy with .02lumens again.

 

[ti-force]

Is it possible for a protected battery to blow up like that?

Would a protected 14500 be capable of supporting the short bursts we're talking about?

Of course if you're looking for a pocket rocket does it have to be practical? You could try a self-destructable light with 1750ma or 2100ma driver with 3 modes and a 'burst' that is totally impractical and going to ruin your battery life, melt the torch if acidentally left on on high, but is also one heck of an impressive little rocket. *odds are tailcap measures won't reach the 2.1A theoretically permitted by the driver:I suspect because of too much internal resistance in the cell.

What driver are you referring to and what emitter would you recommend for this beast?

 

[The Dane]

@ Linger

Do you cross the street?
Eat meat?
Consume alcohol?
Do you get older?

All of the above vill at some point kill you but not as fast as boredom!!!!

How many have had a Lixx blowup?




So in essens to the topic tarter:
Be cool and use common sence, it'll be a lot of fun

 

[ti-force]

My home made running headlight has 2 XPG's in parralel and a custom linear regulator. I can run it at 1500ma with a 14500 but I do not normaly push it that hard. The voltages sags quickly and it drops out of regulation. At 1000ma it stays in regulation well with a 14500 cell so I think that's about the limit for good regulation.

my previous design was an MCE but I never tried that with a 14500 only 18650 cells. It's been retired now as the new light is considerably more efficent and lighter with the 14500. If I want more output I can use an 18650 and get 2000ma which is as good as the old MCE light at max.

Ifor

:thumbsup:

That's pretty darn cool!!

 

[Linger]

In truth I dunno where you'd find this in a 15mm diameter board. For an standard 18mm (C2, 6P, Solarforce L2) light, Shingingbeam.com has 8x7135 low-mid-high driver. You can desolder a few to make it a 5x or 6x. For an eight inch long light, it'll really impress :devil:
hrm, quick search reveals cell may vent overheated, but it seems the explosive events have involved 2 cells. So maybe one cell won't pipe bomb on you, just melt? You reseach how unsafe it is for yourself. The point behind this is you're aware that if you charge it up and throw it in your luggage, accidental activation could have dire consequences. Somepeople design paramaters to make safe lights, others try to max output potential knowing it requires an advanced user to maintain safety parameters that the design removed. Like, keep the light locked out, when you use it if it gets hot, turn it down. NO ok?
I just don't want anyone thinking I've mis-led you into thinking this was an appropriate configuration.
The lame seems to think it boring for me to warn you, I accept that, for who can say who may stumble on this thread? If you want rational, 800ma. Overdoing it is 1A. Ridiculous is +1.5A

 

[ti-force]

In truth I dunno where you'd find this in a 15mm diameter board. For an standard 18mm (C2, 6P, Solarforce L2) light, Shingingbeam.com has 8x7135 low-mid-high driver. You can desolder a few to make it a 5x or 6x. For an eight inch long light, it'll really impress :devil:

I have about 25 AMC7135 boards that are 17mm. 17mm is as big as I can go with this light, so maybe these will work.

You reseach how unsafe it is for yourself.

Will do. I've done some research, but I'll do more.

The point behind this is you're aware that if you charge it up and throw it in your luggage, accidental activation could have dire consequences. Somepeople design paramaters to make safe lights, others try to max output potential knowing it requires an advanced user to maintain safety parameters that the design removed. Like, keep the light locked out, when you use it if it gets hot, turn it down. NO ok?
I just don't want anyone thinking I've mis-led you into thinking this was an appropriate configuration.
The lame seems to think it boring for me to warn you, I accept that, for who can say who may stumble on this thread?

I understand completely where you're coming from. There's no telling who might read this thread and not understand the danger of some battery types, but rest assured, I'd never throw a light like that into a luggage bag with a battery installed. In fact, truth be known, I probably won't use it very often and when it's not in use, it will be stored without a battery in it.

 

[ti-force]

On second thought, I just found the drivers you're talking about (at shiningbeam.com) and those are 17mm boards:twothumbs. I think this might be perfect for what I want to do.:naughty:

 

[Justin Case]

If you want to run an MC-E at 1000mA (250mA per core for the LED wired in 4P) and are willing to use a 14mm diam driver, then I suggest a GD1000 boost/buck driver. It'll run in regulation from about 2.5V up to the driver's max of 5.4V. 14500 is probably about like 16340 in terms of performance. I would say that as long as the cell can maintain at least 3.5V under load (about 1A draw), you'll run in full regulation.

A roughly 2C current load on the 14500 is stressing the cell, though. So cycle life might suffer.

See my LED turbo tower build thread using this configuration (I'm using 3xC NiMH cells instead of 1xLi-ion, however).

 

[Linger]

I always take Justin Case's comments in high regard, the posts are always well directed and as honest as he knows.
In this case, I'm going to pull out from it that the shiningbeam board @ 1000ma is acceptable.
I understand this is your light, but consider, if you removed one of the chips (left 7x) your low gets lower and medium drops down a bit, maybe not noticable by eye but brings it closer to cells capacity and take run-time closer to 1H on medium. You'd get an nice low (~120ma), a solid medium (900ma) and a ridiculous high.
My first cpf light was a Saberwolf modded Ultrafire MCU-C7 with a warm MC-E, 1.8A draw on high from a 7" long 16340 based light. Small enough it's concealed within my hand, its a sunburst that lights up the street. Total 'wow' factor that lasts for weeks on low but can drain a battery 15min full open.

 

[jasonck08]

If your looking to mod a small light, and what to drive a MC-E pretty hard you could use an IMR16340, according to the specs they can take over 4A discharge, so you could safely drive an MC-E @ spec.

Also, I wouldn't consider running an MC-E at <1.4A. It's a waste of money in my opinion.

The XP-G R5 is a cheaper and more efficient emitter. I've had great success with driving the suckers to 1.4A using a 4x 7135 board. You just need good enough heatsinking. I've driven 2, XP-G's in a maglite @ 2.8A, and the brightness is comparable to a P7 or MC-E.

 

[Justin Case]

Don't get me wrong, I think that AMC7135-based drivers are great for 1xLi-ion applications. I'm using them in several applications, including an LED turbo tower. If a 17mm diam driver is more convenient, and if price is important, then an AMC driver is definitely preferable to the GD1000. I presented the GD1000 to provide another choice which might be more suitable in size considering the desire to use a 14500 (AA-size) cell.

Regarding the XP-G vs MC-E, there are pros and cons to both.

The XP-G tint lottery IMO is iffy at best and I think that the chances of getting a non-greenish tint are low. Neutral and warm tints are still unavailable for the XP-G. On the other hand, the MC-E is more of a hassle to connect since you are probably looking at connecting its tiny terminals in 4P, if you work with a bare emitter. If you use an MC-E on a star, then you just buy the appropriately wired version.

An M-bin MC-E is rated at 430 lumens at 350mA per core (1.4A total). An XP-G R5 tested by jtr1962 put out about 440 lumens at 1.4A. Basically a wash. However, the XP-G is being overdriven at that drive current, while the MC-E is well within spec. Both have very low Vf, which is good.

I would expect that for the same reflector, the XP-G will have a brighter hot spot than the MC-E and thus better throw.

Underdriving an MC-E is a more expensive way to go. Even the DX/KD prices are in the ~$20 range, vs about $10 for an XP-G on an MCPCB.

But I wouldn't sell short an underdriven MC-E. My MC-E/GD1000 build runs very cool, with a very long run time. The LED draws only about 3W, yet delivers an estimated 300 lumens.

 

[ti-force]

If your looking to mod a small light, and what to drive a MC-E pretty hard you could use an IMR16340, according to the specs they can take over 4A discharge, so you could safely drive an MC-E @ spec.

Also, I wouldn't consider running an MC-E at <1.4A. It's a waste of money in my opinion.

The XP-G R5 is a cheaper and more efficient emitter. I've had great success with driving the suckers to 1.4A using a 4x 7135 board. You just need good enough heatsinking. I've driven 2, XP-G's in a maglite @ 2.8A, and the brightness is comparable to a P7 or MC-E.

I wish AW offered an IMR14500. That would be perfect for my needs. I have a single 123 light, but it's too short for my tastes. If I had one a little longer, that would be a great host. I may try to put an MC-E in my Eagletac T10C2. That would still be a smaller light, but 1x 18650 capable.