XP-G drop-in and problems - I need some schooling

I've got an R4 drop-in. Single - mode, run at 1.4 amps. 3.6 to 6 volts.

I put two cr123s in it and it lights up fine and has worked fine for two weeks. Current at the tail cap is a steady 1.39 to 1.40. All good here. Exactly what I wanted.

Finally get my 18650s (AW - 2600 maH) and my charger. Charge them up to 4.18 and 4.20. Put one in and the light is noticeable dimmer. I look closer and it's blinking. I try to measure current at the tail cap and it's all over the place. I made sure I was being very still but it fluctuates.

So I throw the other 18650 in and it does the same thing. Then I noticed this.


After ten minutes of blinking, dim output I measured the 18650 at 4.08. I measured it at 4.18 before putting it in. That's .10 volts for every 10 minutes. After 40 minutes the battery will be at 30%. At 1 hour I'll be at 3.6v.

How is it running through 18650s much faster than cr123s, but with a dim BLINKING output. What is wrong with this thing? Driver maybe?


Now I've been looking for an answer to this question, but haven't found it. If I have a drop-in, and lets go with the range of this R4 drop-in, with a voltage range of 3.6 to 6. That allows my 18650 and two cr123s. If it was running at 1.4 amps, would it be brighter with the primaries? I mean, noticeable brighter?

I bought 18650s for the "guilt free lumens". I just didn't realize it was going to be dimmer with all my drop-ins that support both battery types over my primaries. This second part is where I need a learning lesson.

If this is a DX/KD drop-in, i'd suspect it's a driver problem.

If the driver is designed for 3.6 - 6.0v, it should be working fine, but it appears that particular driver prefers higher voltages.

I have a gut feeling it's a NB drop-in.

Black Rose said:

If this is a DX/KD drop-in, i'd suspect it's a driver problem.

If the driver is designed for 3.6 - 6.0v, it should be working fine, but it appears that particular driver prefers higher voltages.

Click to expand...

It's not a DX/KD. I'm sending it back to where it came from tomorrow to be looked at. I just don't want to bring up who made it for me until afterwards. Giving them time to back their product.

I just want to make sure it isn't something else. I too suspect a driver issue.


I'm just a little disheartened with my 18650s. I have another drop-in and it is also noticeable dimmer with 18650s over primaries. I thought the drivers were designed to put the same power at the LED with both setups giving equal output. I am assuming some do and some don't. I guess mine is one that doesn't with the other drop-in and I'm hoping my R4 drop-ins driver is just flawed and it isn't also going to be dimmer with an 18650. It sort of defeats the purpose of the rechargeable setup for me

I've got an XR-E drop-in here (came with a light I bought) that has a driver that can handle 4v - 11v.

It appears to produce the same amount of light whether powered by a pair of CR123A primaries, a pair of 16340s, or 1x17670/18650.

It sounds like the driver in your drop-in has an issue.

It's frustrating, but drivers can be finicky things at times. It'll get resolved.

I've had a really expensive driver crap out on me for no apparent reason, so don't get discouraged with the 18650s.

The P4 DX drop-in I mentioned (sku 6090) has a range of 3 to 18 so.. I'm going to chalk the difference in output up to that It's in a 6P on my fiances nightstand with primaries so I really don't care.


However yea I think your right. I'm sending this one off to be fixed so it's no big deal. I was just worried I was going to get a good module, but with the dimmed output.

Thanks for the quick answer.

If it helps, from purchasing several multi-voltage XP-G R4 and R2 drop-ins they make more OTF lumens when using close to the Max input voltage.

Still; my tail readings reveal similar total watts but always more peak watts at the higher voltage inputs. Driver problems are out of the hands of the custom builders and I have had some of the best fail on me, but thankfully they are all CPF members that back up their products.

There is no standard method for specifying the voltage range for a driver. The upper limit is often based on the maximum rating of the buck, boost, boost-buck, or linear regulator IC that is used. Or sometimes, there is some other component that is the limiting factor (e.g., a diode), while the converter IC can actually run at a higher voltage. In addition, the max rating could be a recommended max or an absolute max.

The lower limit is typically the iffy figure. Is it the minimum voltage required to run in regulation? Is it the minimum rating of the buck, boost, boost-buck, or linear regulator IC? Is it the voltage for initial LED turn-on (and which LED -- a new XP-G, an old XR-E, a Seoul P4,...?). Is it the voltage that gives 50% of the rated output current (again, which LED is used when determining this)? Something else? Who knows?

What kind of driver is it? Buck? AMC7135 or similar linear regulator?

Hmm... doesn't sound like a healthy circuit.

It draws 1.4A at 6V from the two CR123 cells. That raises some eyebrows. I would expect 1.4A tailcap draw from ONE 18650. Two fresh CR123 cells will be slightly over 6V. A decently regulated circuit should draw considerably less current from 6V compared to 4.2V.

What DC-DC board did you use for the build? What drop in is it? Is it a DX? I have seen others spec 7135 based designs as being 6V capable... but I don't think they are optimal for Vin this high.

Donno what driver it is. Just it's an XP-G R4 ran at 1.4 amps with an input range of 3.6v - 6v.

However, when measuring at the tailcap, I thought I should be reading 1.4 with primaries or an 18650. It is ran at 1.4 amps? Is amps not current draw?

Amps and current draw mean the same thing but you shouldn't expect the same current from both battery configurations. The 2 x 123 setup should have a lower current draw because it's higher voltage means less current (amps) is needed to hit the same power rating. Usually when manufacturers say the driver is "1.4A" or "1.0A" or whatever, that means how much current the LED itself is supplied with, not necessarily how much is drawn from the cells.

Like Kramer said, 1.4 A at 6V seems high, that's about 8.5 watts of power.

Wiggle said:

Amps and current draw mean the same thing but you shouldn't expect the same current from both battery configurations. The 2 x 123 setup should have a lower current draw because it's higher voltage means less current (amps) is needed to hit the same power rating. Usually when manufacturers say the driver is "1.4A" or "1.0A" or whatever, that means how much current the LED itself is supplied with, not necessarily how much is drawn from the cells.

Like Kramer said, 1.4 A at 6V seems high, that's about 8.5 watts of power.

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Ah so it should be backwards from what I've got.

Sometimes my 18650 draws from .55 to .75 and then sometimes it's drawing around 1.00 - 1.20. Then sometimes it's drawing from .20 to 1.20. It's just a big fluctuating cluster ****.

My primaries draw a steady 1.4 or 1.39.


I should be drawing around 1.4 with my 18650, but less with my primaries. Whether or not those numbers are right, mines backwards Sounds like I've just got a bad driver.

The tail current draw measurement depends on the type of driver and the input voltage.

For a constant current buck driver, the tail current draw will steadily decrease roughly in proportion as Vin increases. Thus, if the current draw is say 0.8A at 5V, then it will be about 0.4A at 10V (assuming that the driver can run at these voltages). Also, tail current draw in regulation is not the same as the drive current.

For an LDO regulator like the AMC7135, the current draw in regulation will be constant from Vmin to Vmax. Thus, if you have a 4xAMC7135 driver (1.4A drive current), you should measure ~1.4A at the tail once Vin exceeds the voltage needed to run in regulation and it will stay at ~1.4A even as Vin increases.

The voltage range for your drop-in suggests an AMC7135-type driver, but you never know. If it is an AMC-based driver, then 1xLi-ion should run an XP-G just fine.

When you say that the drop-in blinks, do you mean a steady, periodic blink or a more random flickering periodicity? For an AMC-based driver, if the board uses diodes for reverse polarity protection, it might be that your XP-G's Vf is too low for the driver to run right. The thing that doesn't make sense is the rapid draining of your AW18650 cells.

6v @ 1.4A = 8.4watts

18650 @ 1.2A = 5watts

Yeah , kind of backwards . If it works with primaries ?
But kind of sounds like a short to me , try unscrewing the reflector just a little and see if it becomes OK .

I found with XP-G that the LED is so small , a lot of the time you need to screw the reflector down [ possibly too hard ] and the wires to the led get crushed and then there is a short , I found backing out the reflector so not to crush the wires and then super gluing it in position solved the problem . [ Super glue reflector in position ]

I just picked up the Dereelight XP-G R5 P60 drop-in and it has that 1.4A driver. I put my IMR 18650 cell and I get a solid 1.5A at the tail. MrGman will test it monday for OTF lumens. I think it will be close to 300 OTF, but my Anto XP-G R4 306 OTF version looks noticeably brighter. It reads 1.40ish at the tail.

bigC

old4570 said:

6v @ 1.4A = 8.4watts

18650 @ 1.2A = 5watts

Yeah , kind of backwards . If it works with primaries ?
But kind of sounds like a short to me , try unscrewing the reflector just a little and see if it becomes OK .

I found with XP-G that the LED is so small , a lot of the time you need to screw the reflector down [ possibly too hard ] and the wires to the led get crushed and then there is a short , I found backing out the reflector so not to crush the wires and then super gluing it in position solved the problem . [ Super glue reflector in position ]

Click to expand...

Not necessarily backwards if it is an AMC7135-based driver, which I suspect it is. The 2x123A @1.4A is expected for 4xAMC7135. Also, it isn't 6V under load. At 1.4A, the cells no doubt sag to less than 2.5V per cell.

Normally, 1x18650 should power 4xAMC7135 in regulation and thus draw 1.4A at the tail as well. However, if there is some high contact resistance, coupled with a low Vf emitter and reverse polarity protection diodes on the AMC driver, the light might flicker and also draw less than 1.4A.

It's always good to check the simple things like shorts and such, but I doubt it is a short since the light seems to work as expected with 2x123A.

Super glue is a horrible adhesive to use with Cree LEDs. The vapors from cyanoacrylates can damage (cloud) the dome. Cree explicitly warns against using super glue.

bigchelis said:

I just picked up the Dereelight XP-G R5 P60 drop-in and it has that 1.4A driver. I put my IMR 18650 cell and I get a solid 1.5A at the tail. MrGman will test it monday for OTF lumens. I think it will be close to 300 OTF, but my Anto XP-G R4 306 OTF version looks noticeably brighter. It reads 1.40ish at the tail.

bigC

Click to expand...

That's odd, all the drop-ins on the dereelight site state 1.2A. Is yours standard?

qtaco said:

That's odd, all the drop-ins on the dereelight site state 1.2A. Is yours standard?

Click to expand...

I got it from Craig for testing and the label reads as follows:

3SD XP-G R5
Input: 2.8~4.2v

Maybe they sent Craig (csshih) a higher current model considering he will review it

The last sentence is just for fun, not conclusive and just my silly opinion.:naughty:

I just saw the Dereelight website now and sure enough it is suppose to be a 1.2V regulated drop-in.

------------------------------------------------------------------------------------------
3SD(3-stage digital) Cree XP-G R5 module

• 1. • Emitter: Cree XP-G R5.
     • Input Range: 2.8~4.2V
     • Output Range: 1.2A
     • Battery Type: 1x18650, 1x17670
     • Features:

EDIT: I just put in a topped of IMR 18650 cell at 4.21v and now this drop-in reads 1.9A~2A at the tail..

I got the module from FlashlightConnection. :shrug:

now that you're getting 2A, I doubt a dealer would have any 2A modules on hand.. bad idea! :nana:

that is very strange though.. the non-IMR cell would have easily provided the 2A.. so it's the higher voltage from the IMR doing this. :thinking: