# Flashlights with "parasitic drains"



## Mikellen (Mar 3, 2009)

Can someone please inform me of which specific brands and models of flashlights have a very slight drain on the battery even while not in use? I know the D10 (Edgetac?) has a parasitic drain, but what are some examples of other brands? Do all or most programmable lights have that type of battery drain? What about Fenix, Olight, and Surefire?
I'd appreciate if anyone can provide an explanation as to what are the characteristics of a flashlight that would determine the need for a constant and slight current draw on the battery.

Thank you.


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## techwg (Mar 3, 2009)

I would like to know also, i keep away from lights that drain like that. It would be good to have a conclusive list to know what to not buy.


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## Beacon of Light (Mar 3, 2009)

The Streamlight Tasklight 1AA and 2AA do this. Not sure why they incorporated this as a necessity. I overlook that as it is a nice light and it has a low/high setting as well as strobe and I always lockout that light to make this a moot point.

I guess the same thing can be said for the Maglite that uses a NiteIZE IQ switch. Again I lock it out to avoid this problem.


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## Everett (Mar 3, 2009)

Most programmable lights will do this. Novatac and Ra lights do this, but you should be aware that the draw is in the microamp range. At the levels I measured on my NT and Ra, the draw was so low that the battery's self drain outweighs it. It would take much longer than the battery's 10-year shelf life for the light's drain to empty it.


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## Beacon of Light (Mar 3, 2009)

Everett said:


> Most programmable lights will do this. Novatac and Ra lights do this, but you should be aware that the draw is in the microamp range. At the levels I measured on my NT and Ra, the draw was so low that the battery's self drain outweighs it. It would take much longer than the battery's 10-year shelf life for the light's drain to empty it.



Compare that to when you use common NIMH batteries that do have a high discharge rate already, coupled with the parasitic drain (is this the proper term for this phenominon?).


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## cave dave (Mar 3, 2009)

The Nitecore PD lights can be locked out by untwisting the bezel. As long as they are not in "clicky" mode there is no drain.

Some of the Fenix models had a incorrectly speced o-ring in the tail of the light around the spring. This tail cap allowed some current to pass and acted as a parasitic drain. 1 out of 5 of my tailcaps had this problem. I removed the o-ring as its only purpose was decorative. The tail cap can be tested with a multimeter but I don't remember how. The ohm-meter function I presume.
Some other lights have also displayed similar problems.


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## Phaserburn (Mar 3, 2009)

I hate parasitic drain lights; I just do.

Any light with a "find me" blink led will be a drainer. There are a bunch of these, especially some headlamps.


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## cave dave (Mar 3, 2009)

Everett said:


> Most programmable lights will do this. Novatac and Ra lights do this, but you should be aware that the draw is in the microamp range. At the levels I measured on my NT and Ra, the draw was so low that the battery's self drain outweighs it. It would take much longer than the battery's 10-year shelf life for the light's drain to empty it.



However there is more to it than that, when CR123's sit unused they form a passivation layer between the cathode and anode which stops current from flowing and is the reason a primary lithium has such a long shelf life. I am not sure but the parasitic drain may interfere with the formation of the passivation layer and therefore cause the self drain to be much higher than expected.

However as a flashaholic if you let your lights sit unused so long as to notice this drain then Sasha will hunt you down and take away your CPF membership card.


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## Lightraven (Mar 3, 2009)

This has been a minor problem with almost all of my LED flashlights, except the Surefire X-300 which has only one brightness level. I have experimented with CR-123A drainage in my Favourlite 3 watt headlamp, HDS EDC 60, Novatac 120T (slight), and First Light Liberator--all multi level lights. The results were discouraging. The EDC60 would drain a half drained CR-123A from 60 lumens at turn on to .8 lumens (or whatever minimum is) at turn on in 3-4 months. The Favourlite could kill 2 fresh cells in 6 months to a year. The Liberator gradually drained one of its two new 123 batteries and would lock itself out when momentary or strobe was activated. The 120T has a slower drain, not too bad. 

I have read on CPF my Nightcore Extreme also does this.


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## Mikellen (Mar 3, 2009)

Thanks for all of the responses. I recently purchased a Fenix L1D and I hope the switch design and head circuitry does not have that slight constant battery drain. I am looking to purchase either another AA or a single CR123A battery powered flashlight as my next purchase. I know it might seem trivial to some, but I just don't want to purchase a flashlight that draws current from a battery when not in use. 
Please keep the examples coming.

Thank you.


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## Lightraven (Mar 3, 2009)

Oh, yeah. Forgot to mention my Fenix P2D Cree. I have had some problems with two of them, but not battery draining. They seem to hold a charge.


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## selfbuilt (Mar 3, 2009)

Mikellen said:


> Thanks for all of the responses. I recently purchased a Fenix L1D and I hope the switch design and head circuitry does not have that slight constant battery drain.


You should be fine - the faulty tailcap o-ring was from a limited period of time (back when Fenix was using mainly Q2 emitters, and some of the early Q5s). And in those cases, removal of the ring or locking out the tailcap resolved the problem (I have one such switch myself, just keep it locked out).

As previously mentioned, a low-current draw when off is typically necessary for programmable lights with electronic switches. In a well-designed light, it is generally neglible and not a concern. Tailcap lock-out can again typically resolve the issue if you are worried.

The Streamlight 1xAA and 2xAA tasklights (Nichia emitters) from a couple of years ago were a particularly egregious example of a poorly-designed electronic switch. The drain was sufficient to discharge a full battery within a matter of months. Fortunately, that's a rare anomaly.


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## Beacon of Light (Mar 3, 2009)

selfbuilt said:


> The Streamlight 1xAA and 2xAA tasklights (Nichia emitters) from a couple of years ago were a particularly egregious example of a poorly-designed electronic switch. The drain was sufficient to discharge a full battery within a matter of months. Fortunately, that's a rare anomaly.



Did they redesign the Streamlights since then. They are almost my favorite design for a 1AA/ 2AA and bang for buck light I have ever owned. The drain is the only reason I have a beef with it.


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## selfbuilt (Mar 3, 2009)

Beacon of Light said:


> Did they redesign the Streamlights since then. They are almost my favorite design for a 1AA/ 2AA and bang for buck light I have ever owned. The drain is the only reason I have a beef with it.


Sorry, don't know if they ever fixed it. Unfortunately, those light don't have anodized threads, so tailcap lock-out isn't even an option. But I agree they have a nice form factor.


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## Mikellen (Mar 3, 2009)

Some flashlights that I'm interested in are the Proton Pro, NDI, Lumapower ConneXion X2, 1 cell Surefire lights, and the Olight M20 Warrior Premium R2. Any of these have a "parasitic battery drain"?


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## Marduke (Mar 3, 2009)

I know the NDI has none. Not sure about the others.


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## Flying Turtle (Mar 4, 2009)

I've never seen this mentioned in regards to the Proton Pro, and I think I've read everything mentioned about it here. Not to say it doesn't exist, but since the same UI is used in many Photon lights, seems it would have been noted by now.

Geoff


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## houtex (Mar 4, 2009)

First Light Tomahawk.


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## Splunk_Au (Mar 4, 2009)

Fenix P1D CE.


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## HKJ (Mar 4, 2009)

Splunk_Au said:


> Fenix P1D CE.



NO, Fenix does not have any parasitic drain.


LiteFlux does, but the drain is very low, i.e. it takes many years to drain the batteries.
Nitecore has a rather high drain, i.e. it will drain the batteries in less than a year (At least for some models).
Zebralight, the lights with buttons uses standby power

A general rule for detecting light with standby power drain is to look after the switch, if it is a non-locking switch, the light has a microprocessor that is always powered to control the power and for some lights they also need a running boost converter to power the microprocessor (That will increase the drain).


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## Marduke (Mar 4, 2009)

General rule of thumb is lights with an MCU switch will have some small drain. Lights with traditional clicky switches will most likely not.

I haven't seen it spelled out explicitly, but just because a light has some user defined memory does NOT mean it necessarily has a parasitic drain. Most of these lights remember their user setting even with no battery installed.


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## Mikellen (Mar 7, 2009)

According to post# 4, RA lights have a parasitic drain. Does this also include the RA Twisty or just the clicky versions.

Thanks.


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## Bushman5 (Mar 7, 2009)

i go thru batteries so quick (2, 3 4 times daily) that parasitic drain is not an issue. :nana:


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## WadeF (Mar 7, 2009)

I have a bunch of lights that have, as you describe, a "parasitic drain". It has been a total non-issue. Unless you plan to shove a battery in a light, and wait a year or two to use it, it shouldn't be a problem. If you use a light so infrequently, leave the battery out, or lock out the light if you can. To put this lights on some kind of black list, or avoid list, seems silly. Some of my favorite lights do this, Liteflux LF3XT, Nitecore EX10/D10, Zebralight H30, H60.


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## gswitter (Mar 7, 2009)

WadeF said:


> If you use a light so infrequently, leave the battery out, or lock out the light if you can. To put this lights on some kind of black list, or avoid list, seems silly.


But it isn't always practical to keep the batteries outside the light.

I don't mind a light that puts a small load on the battery when "off" if it's a light I use on a regular basis and will be frequently changing/recharging the battery anyway. But lights I have stashed for emergencies tend to not get used for very long periods, and I won't even consider a light that can't truly be turned off for these cases.


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## Marduke (Mar 7, 2009)

gswitter said:


> But it isn't always practical to keep the batteries outside the light.
> 
> I don't mind a light that puts a small load on the battery when "off" if it's a light I use on a regular basis and will be frequently changing/recharging the battery anyway. But lights I have stashed for emergencies tend to not get used for very long periods, and I won't even consider a light that can't truly be turned off for these cases.



Any light in extended storage should always be stored separately from the cells.

Lights in emergency storage which must be kept in operational status are also usually KISS lights, so that anyone can use them at a moment's notice under duress without having to read an instruction manual first. That is most definitely NOT most of the aforementioned lights.


Either way, moot point.


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## Dan FO (Mar 7, 2009)

Mikellen said:


> According to post# 4, RA lights have a parasitic drain. Does this also include the RA Twisty or just the clicky versions.
> 
> Thanks.



Typically a twisty does not drain because when you turn it off you are breaking battery contact. This is what is making it turn off.


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## gswitter (Mar 7, 2009)

Marduke said:


> Any light in extended storage should always be stored separately from the cells.
> 
> Lights in emergency storage which must be kept in operational status are also usually KISS lights, so that anyone can use them at a moment's notice under duress without having to read an instruction manual first.


AFAIC, emergency storage is extended storage.

And I'd assume the point of this discussion is to determine which lights shouldn't be used for emergency storage because of the potential for draining the battery when "off". I consider the HDS/NovaTacs and maybe even Mr. Bulks KISS lights, but I wouldn't consider them for emergency lights because there is some drain on the battery (regardless of how small that drain actually is).


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## carrot (Mar 7, 2009)

Please people use your noodle. Any light that has breaks the circuit physically (real clickies, vs. electronic clickies) will not have a parasitic drain. 

http://cpf.carrot.googlepages.com/flashlight_guide#clicky


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## gswitter (Mar 7, 2009)

Mikellen said:


> According to post# 4, RA lights have a parasitic drain. Does this also include the RA Twisty or just the clicky versions.


Both. Due to the sprung contacts at both ends of the battery, you don't break the circuit in the Ra Twisty when you turn it "off".


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## Mikellen (Mar 12, 2009)

I just purchased an Olight M20 Warrior Premium R2. 
Anyone know if this flashlight has a parasitic drain? (Don't know the correct term).

Thanks.


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## HKJ (Mar 13, 2009)

Mikellen said:


> I just purchased an Olight M20 Warrior Premium R2.
> Anyone know if this flashlight has a parasitic drain? (Don't know the correct term).
> 
> Thanks.



It does not, the switch disconnects all power.


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## jayb79 (Mar 27, 2009)

My HDS B42 has a 18650 tube. In about 3 weeks just sitting on the shelf the 18650 is to low to turn on the light.


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## Bullzeyebill (Mar 27, 2009)

jayb79 said:


> My HDS B42 has a 18650 tube. In about 3 weeks just sitting on the shelf the 18650 is to low to turn on the light.



Interesting. Drain should be in 1/100,000 of a volt range. Email, Henry about the excessive drain on your HDS. What voltage did you store it at?

Bill


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## jayb79 (Mar 27, 2009)

It was fresh of the charger. I just loosen the tube when i store it and it is ok for now. If i get some time this weekend i will see if i can see what it is drawing. If the 18650 has only 1.1 ah of capacity then 3 weeks is 504 hours divided into 1.1ah is only .002ahs of drain to kill it. So it may not have a problem.


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## Bullzeyebill (Mar 27, 2009)

jayb79 said:


> It was fresh of the charger. I just loosen the tube when i store it and it is ok for now. If i get some time this weekend i will see if i can see what it is drawing. If the 18650 has only 1.1 ah of capacity then 3 weeks is 504 hours divided into 1.1ah is only .002ahs of drain to kill it. So it may not have a problem.



A freshly charged 18650 will have between 2000-2200mAh. A good 17500 will have the 1.1 Ah. Should not have that high a drain with your HDS.

Bill


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## Norm (Mar 27, 2009)

You should be able to put your HDS away for a number of years and not have the battery go flat.

I was searching for the HDS beacon run time test but cant find it, I think it is well over 12 months now.
Norm


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## Justin Case (Mar 28, 2009)

The Blackhawk Gladius has a parasitic drain. Fortunately, shelf life is on the order of several years, and the Gladius has a low battery indicator.

OpticsHQ's multifunction tailcap for the SureFire 6P series also drains batteries even when "off". Drain in this case is high. I'd estimate one month shelf life for 2xAW16340.


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## Mikellen (Apr 16, 2009)

O.K. I now realize the RA Twisty has a "parasitic drain". Is there any way to lock out the head to break the circuit in order to stop the ever so slight current flow, and if so would this be practical, (would it be less water resistant?), or should I just accept the fact that this light has a "parasitic drain" and maybe will have to replace the battery more often.
I really like what I've read about this light and I am considering on purchasing one but I admittedly have a hang up (whether warranted or not) with "parasitic drain" type flashlights. 

Thanks for any answers.


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## carrot (Apr 16, 2009)

Don't focus too much on the idea of parasitic drain. It is very, very low on most lights and if you carry your light at all then you will never be able to blame the parasitic drain for a dead battery. If you want to store your lights then obviously just take the battery out!

I was pretty sure the RA Twisty did not have parasitic drain, only the Clicky. Only lights with electronic clickies have parasitic drain.


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## Ble (Apr 17, 2009)

Anyone know if the Liteflux LF2 has "parasitic drains"?


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## Bullzeyebill (Apr 17, 2009)

Ble said:


> Anyone know if the Liteflux LF2 has "parasitic drains"?



Yes. Another, if not already mentioned, is ArcMania Extreme III AAA. Excellent circuit. Good thing it has parasitic drain. Probably draws about 1/1,000,000 of a volt. 

I think that the OP's question has been answered, and I, personally, can think of no reason to hold a bias against so called "parasitic drain" as a reason not to like a flashlight, particularly with the information presented in this thread. Flashlight technology is evolving, good for that, and different electronics are being employed along the way to enhance our use and enjoyment of flashlights.

Bill

Bill


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## HKJ (Apr 17, 2009)

Ble said:


> Anyone know if the Liteflux LF2 has "parasitic drains"?



All LiteFlux has a standby drain, but it is usual very low.
I have measured LF2X to 5uA on NiMH and 20uA on LiIon. That means that you have to recharge LiIon each year and on AAA batteries you just uses their "use before" date, the drain will not empty the battery premature.


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## imgadgetman (Apr 20, 2009)

I carry the Fenix P1D in my pocket as a backup. When I put in a fresh surefire it measures 3.27v. Two months later without using it the voltage is about 3.10. It is a twisty so I cannot twist it enough to stop contact with the spring. Also I carry a Fenix LOD as a backup to my backup and it seems to have the same parasitic drain. I was thinking of doing a voltage drop check for one month on both of these comparing it to my P3D CE with clicky. If I want to stop parasitic drain, what material would be the best to place between battery and positive end contact? Plastic is available with very thin layers, cardboard?

imgadgetman


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## HKJ (Apr 20, 2009)

imgadgetman said:


> I carry the Fenix P1D in my pocket as a backup. When I put in a fresh surefire it measures 3.27v. Two months later without using it the voltage is about 3.10. It is a twisty so I cannot twist it enough to stop contact with the spring. Also I carry a Fenix LOD as a backup to my backup and it seems to have the same parasitic drain. I was thinking of doing a voltage drop check for one month on both of these comparing it to my P3D CE with clicky. If I want to stop parasitic drain, what material would be the best to place between battery and positive end contact? Plastic is available with very thin layers, cardboard?
> 
> imgadgetman



Neither of these lights does have any standby drain, except maybe due to moisture. The contact is between the top of the tube and the PCB in the head, when you break that contact, you break the circuit.


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## Russel (Apr 20, 2009)

imgadgetman said:


> I carry the Fenix P1D in my pocket as a backup. When I put in a fresh surefire it measures 3.27v. Two months later without using it the voltage is about 3.10. It is a twisty so I cannot twist it enough to stop contact with the spring. Also I carry a Fenix LOD as a backup to my backup and it seems to have the same parasitic drain. I was thinking of doing a voltage drop check for one month on both of these comparing it to my P3D CE with clicky. If I want to stop parasitic drain, what material would be the best to place between battery and positive end contact? Plastic is available with very thin layers, cardboard?
> 
> imgadgetman



As TurboMan suggested in a similar thread, with many flashlights you can simply unthread the tail cap so that the battery is disconnected. I store my Fenix L2D in my briefcase that way. It also protects against accidentally turning it on while it is a bag or pocket, etc.


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## cave dave (Apr 20, 2009)

Norm said:


> You should be able to put your HDS away for a number of years and not have the battery go flat.
> 
> I was searching for the HDS beacon run time test but cant find it, I think it is well over 12 months now.
> Norm


It is now 31 months. The thread is over on Marketplace.
http://www.cpfmarketplace.com/mp/showthread.php?t=132584



carrot said:


> I was pretty sure the RA Twisty did not have parasitic drain, only the Clicky. Only lights with electronic clickies have parasitic drain.


The Ra is not your normal twisty. Curent goes through the threads at all times (including a very small parasitic drain). The loops of wires are just signal wires. The microprocessor looks for the signals to tell it what mode to be in.

For instance, when you first screw the battery cap on it lights up dimly for 1 second to let you know the circuit recognizes a good battery. There is no way to lock it out.



Russel said:


> As TurboMan suggested in a similar thread, with many flashlights you can simply unthread the tail cap so that the battery is disconnected. I store my Fenix L2D in my briefcase that way. It also protects against accidentally turning it on while it is a bag or pocket, etc.


The P1D and LOP don't have a tailcap to unscrew. So that doesn't help imgadgetman.


Not all Parasitic drains are equal. Some lights have a high drain and others are negligible. It is also possible to have defective lights or software glitches that cause a drain to be higher than it should. Physical issues could be anodize (or that bad fenix oring) that lets just a bit of current flow through. Moisture in the circuit board or switch can also do this. Firmware bugs can also cause the circuit to not enter sleep mode properly.


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## Bullzeyebill (Apr 20, 2009)

We are not sure that the P1D and LOP have "parasitic drain", so let us not jump to conclusions. We need good data not just us guessing around. Too much subjective stuff going on.

Bill


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## Marduke (Apr 20, 2009)

Bullzeyebill said:


> We are not sure that the P1D and LOP have "parasitic drain", so let us not jump to conclusions. We need good data not just us guessing around. Too much subjective stuff going on.
> 
> Bill



They don't. Not guessing, just the nature of their construction.


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## Bullzeyebill (Apr 20, 2009)

Marduke said:


> They don't. Not guessing, just the nature of their construction.



Hi Marduke, uh, the nature of whose construction? Please explain, thanks,

Bill


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## cave dave (Apr 20, 2009)

Marduke said:


> They don't. Not guessing, just the nature of their construction.



The nature of the P2D construction would also indicate no parasitic drain and yet it happened on a few units because of a defective rubber o-ring that could allow a small amount of current to pass when it was subjected to compression. Hard to believe but true.

Any light that relies on the anodizing of two threaded parts to stop current flow might eventually develop a drain when that anodizing wears thin. I'm not saying the P1D would do this because I don't know what happens if the module is energized at the threads.

Also the use of a conductive grease could cause a parasitic drain if it migrates somewhere it doesn't belong.


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## Marduke (Apr 20, 2009)

Bullzeyebill said:


> Hi Marduke, uh, the nature of whose construction? Please explain, thanks,
> 
> Bill




The lights you mentioned...


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## shuter (Apr 21, 2009)

I was wondering about parasitic drain in my Mr. Bulk lights so I asked the creator of the boards, George.

In both the direct drive and regulated boards used in the LionHeart, LionCub, Chameleon and DragonHeart, there is a drain of less than 0.2mA when "sleeping." Using a 750mA RCR123 it will take 80+ days to drain it to 50%. Good to know.

Thanks George! :wave:


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## ntalbot (Apr 21, 2009)

Thank you for starting this thread OP.
My EDC an LF2X, drains it's battery pretty significantly in about 2 months. It's ok for an EDC, I just make sure I charge it once a month, but that would bug me for an occasional use flashlight. Especially if I had primaries in it!!
Do you think the new Olight M30 or the Eagletac M2X will have parasitic drains? I think the Eagletac won't, especially not if you install the tactical clicky.


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## Bullzeyebill (Apr 21, 2009)

ntalbot, this is post 43 in this thread re LF2X parasitic drain.



HKJ said:


> All LiteFlux has a standby drain, but it is usual very low.
> I have measured LF2X to 5uA on NiMH and 20uA on LiIon. That means that you have to recharge LiIon each year and on AAA batteries you just uses their "use before" date, the drain will not empty the battery premature.



Bill


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## crizyal (May 25, 2009)

ntalbot said:


> Thank you for starting this thread OP.
> My EDC an LF2X, drains it's battery pretty significantly in about 2 months. It's ok for an EDC, I just make sure I charge it once a month, but that would bug me for an occasional use flashlight. Especially if I had primaries in it!!
> Do you think the new Olight M30 or the Eagletac M2X will have parasitic drains? I think the Eagletac won't, especially not if you install the tactical clicky.



The Eagletac M2 and M2X does seem to have a "parasitic drain" until you install the optional clicky switch. The switch does in fact lock out the drain. I believe that I have read .7mA standby drain without the switch installed.


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## Bullzeyebill (May 25, 2009)

crizyal said:


> The Eagletac M2 and M2X does seem to have a "parasitic drain" until you install the optional clicky switch. The switch does in fact lock out the drain. I believe that I have read .7mA standby drain without the switch installed.



That sounds high, 0.7mA drain. Maybe 0.007mA would be more like it. 

Bill


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## HKJ (May 26, 2009)

Bullzeyebill said:


> That sounds high, 0.7mA drain. Maybe 0.007mA would be more like it.
> 
> Bill



0.007 mA would have been much better, but it is 0.7mA, draining the batteries in about 4 months.


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## Burgess (May 26, 2009)

How about the LumaPower ConneXion X2 ?



and, the upcoming LumaPower Avenger GX ?





Thank you.

_


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