Fenix LD01 parasitic drain

Dcon67

Newly Enlightened
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Nov 5, 2002
Messages
29
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Massachusetts
I don't know if this light is defective or what...in looking at previous reviews of the LD01, I don't see where anyone has really complained about parasitic drain.

I have an LD01 is SS, that won't last 2 weeks with ZERO use on a fully charged eneloop. Everytime I want to use it, the friggin battery is dead.

What do I do? I guess I can sell it on eBay...I'd feel bad posting it up in the Marketplace here (which is where I got it, btw), since as far as I'm concerned this light is useless.

I guess I'll probably look into an LF2XT....in natural. I want a reliable keychain light for emergency use that will actually light up when I need it. And take a beating without looking to bad. So either SS or natural HA.

I'm open to other suggestions if anyone has any.
 
Has your eneloop been over charged or over-discharged? That could lead to reduced capacity, and the inability to hold a charge. I'm not sure what the parasitic drain on an LD01 is, but it sure should take a lot longer than that.

If you have no way of determining the real capacity of the cell you're using, might I suggest putting a primary Li AAA in its place, and seeing if it is dead in two weeks? If yes, it is the light, if no, it's the eneloop.
 
My LD01 has an eneloop in it and it lasts for months if not used a lot. I would agree with ragista that it has no or virtually no parasitic drain.
 
The design of the LD01 makes it impossible to have parasitic drain as the battery is disconnected from the circuit when off, unless the light is shorting out inside.
 
I would definitely place an Alkaline or Lithium (Energizer) in there first. I think you will find that while rare your Eneloop is defective.

Bill
 
I would say it is possible when you turn it off you are barely turning it off and put it in a position where it comes on by itself without you knowing it as the threads have a slight bit of give enough you can turn it off and push the light together without turning and it will come on but when let go it will go off again. If this is the case when you turn it off turn it half a turn more after it is off and try pushing the light together to see if it comes on at all.
 
It's not the eneloops. I've used four different ones...each dead within a couple of weeks. I think there's something wrong with the light. There's a spring in the tail piece, so loosening it doesn't completely break the contact...and it I do have it loose enough so that wiggling, shaking bending, etc... doesn't make the light flicker on. So I know it's not coming on while in my pocket.

Troy
 
when you back off the head, the body breaks contact with the negative contact ring on the pcb. hence no path for current drain.
 
when you back off the head, the body breaks contact with the negative contact ring on the pcb. hence no path for current drain.

unless the head is not backed off enough like lynx said, ive killed a batt this way - i had backed it off but was fiddling about in my pocket and must have kept pulsing it with the play in the threads, then i guess when i sat in my car to drive everything in my pocket was squashed so the light was on. i prolly back off a full turn now.
 
Well then I don't know....it's definitely not the batteries, so I guess that leaves operator error. Could something like my keys or other metal in my pocket create a weak contact path on the exterior of the light?

Regardless, I'll try a new duracell alkaline and see how long that lasts. I'd be shocked if it goes longer than a month, and I'll leave it unscrewed a turn and a half...to the point I can just see the o-ring starting to emerge.

Watch, with my luck I'll probably end up with it so loose I'll lose the head and be left with just the tail attached to my keys.
 
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Here's one more thought...I'm going to test the latest "dead" eneloop and see how much juice is left. I've got a MAHA 9000, so I can test it with that. Maybe the light is just overly sensative to a voltage drop. This light is regulated since it doesn't dim as the battery weakens, it goes from full brightness to no light at all. So I suppose the battery could just be slightly used up and something defective in the regulation circuitry could be cutting power to the head?

All I know for sure is, it no-worky every time I go to use it. So maybe a clicky would be a better choice for me. I just really liked the SS body, since it survives life on a keychain with no show of wear.

Troy
 
If you have an ohm meter, you can check to see if there is some sort of path from the center or + terminal in the head to the outer shell of the head. It should read infinite ohms. If you have some sort of a connection then there is something wrong.
 
Are you sure that the battery is really dead. I've had two of the LD01's. The SS model always had contact issues. It would at times refuse to work with rechargeables unless I turned it on and off a couple of times in a row. Other times it was fine. I can't help but wonder if this is happening to you and it makes it seem like the battery is dead when it really is just not making good contact. I know it seemed like these contact issues were a lot worse when were less than fully charged. I could take a battery out of my SS model and but it in my black one and it would fire right up.
 
when you back off the head, the body breaks contact with the negative contact ring on the pcb. hence no path for current drain.
...unless something is shorting against the interior of the head. Unlike the Al models, the lack of anodizing on the threads allows the housing of the head to be part of the circuit.

I have an LD01 SS in which this is the case. It won't light up at all and head gets very warm in a matter of seconds. The SS head on any Al body works fine, as does any Al head on the SS body.
 
If you have an ohm meter, you can check to see if there is some sort of path from the center or + terminal in the head to the outer shell of the head. It should read infinite ohms. If you have some sort of a connection then there is something wrong.
+1, I think that the test cited above has a good chance of getting to the heart of the matter.
 
Ok...using my crappy rat-shack multimeter, I measured 600 Ohms from the positive contact in the center of the head to the outside caseing. So I'm guessing that's enough of a connection to allow the battery to drain, without being enough to actually light up the light.

I tested the battery, and it was completely drained.
 
600 ohms? E=IR or I=E/R, 1.5v/600ohms =0.0025Amps or 2.5ma it would take 800 hours to drain a 2000mah battery at that rate or about a month (33 1/3 days). I would say if it is draining it in a few days you are looking at about 10 times the current flow or about 50 ohms
 
600 ohms? E=IR or I=E/R, 1.5v/600ohms =0.0025Amps or 2.5ma it would take 800 hours to drain a 2000mah battery at that rate or about a month (33 1/3 days). I would say if it is draining it in a few days you are looking at about 10 times the current flow or about 50 ohms

Please remember that LD01 uses an AAA cell whose average capacity is 800 mAh

800 : 2.5 : 24 = 13 days for a complete drainage, but probably after 8 days the light is already dead
 
Ok...using my crappy rat-shack multimeter, I measured 600 Ohms from the positive contact in the center of the head to the outside caseing. So I'm guessing that's enough of a connection to allow the battery to drain, without being enough to actually light up the light.

I tested the battery, and it was completely drained.

That measurement doesn't mean anything. Of course current will flow through the circuit when you apply voltage. The point is that unless something weird is going on, turning off the light completely disconnects the battery for the circuit. I'd say look for crap (machining burrs etc) on the upper edge of the battery tube, and similarly on the PC board ring contact that the tube presses against when the light is turned on. Also, when you turn off the light, make a point of backing it off 1/2 turn or so from when the light actually stops lighting up. There is often quite a bit of slop in the threads of those things. Try turning the light only "slightly" off, then compressing it (pressing the head down lengthwise) with your fingers, and you're likely to see it turn on again. It's possible that is happening in your pocket.
 
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