Parasitic Drain

[bykfixer]

The processor should be sleeping most of the time, where quiescent drain should be a small handful of microamps, if that much. Every now and then the processor wakes up, either by a hardware interrupt, or a simple timed interval. Once awake, the processor scans the user interface (probably a single button). If a state-change of is not detected, the processor goes back to sleep. That's the way it's supposed to go. Very, very low parasitic drain should be the norm. Anything short of that is a problem with firmware, a problem with hardware, or a problem with both.

Cheers

Thank you for explaining how it works.

I have some vintage lights (read incan from the 20's to the 50's) that drain the battery in some cases a few days.
Nothing electronic, just seemingly a circuit that never gets completely cut when sliding the switch to off. Some do, some don't. (I wonder if that may be the case to cause this thread.)

Being they aren't very bright anyway I don't figure them as emergency lights and store batteries outside the light(s).

 

[archimedes]

I have a decent collection of flashlights. My true love are the emitters. I am hopelessly in love with LED's, a love that spans decades. To me, the flashlight is a life support system for the LED ....

:welcome:

.... Specifically, what have I stated that is factually inaccurate?

Oboy, where to start.... Parasitic drain is not nearly as power hungry as you think....

If parasitic drain is a big deal for you, charge the battery for one minute once (if that much) a month.

I'm new here. I registered to reply to your comments, which, IMO, are factually inaccurate.

I didn't post anything about factual inaccuracies.

Many ( even most? ) of the flashlight enthusiasts here have personal experience, however, with at least one light having drained a full battery sitting idle in ~ one month or less.

Charging a battery for one minute, once per month, would not solve that problem.

Some flashlight users here must exclusively rely on primary (non-rechargeable) cells, for any of a variety of reasons.

This, too, would preclude simply dismissing the concerns of even relatively "limited" parasitic drain.

I have spent the better part 50 years repairing devices that customers attempted to repair themselves. We had a customer trash a $55,000 bioluminescence microplate reader ....

I would hope that our flashlight experts here would not use their first post on a bioluminescence microplate reader forum to explain how mistaken they all were over there.

It sounds like you have a lot of technical knowledge, however, and hope you will stick around to share it with us here on CPF.

Perhaps you will even learn something here yourself ... cheers

 

[vt2nv]

First and foremost, thank you for your kind welcome.

What is required of the processor in a flashlight? Lacking specifics, but considering input, output and housekeeping tasks, I would say not that much. Wake up, take a look around, go back to sleep. That a turned-off flashlight would drain an 18650 in a few weeks is obscene, indicative of (at least) poorly written code.

I plan on learning a great deal here. Mostly, I use CPF as a resource that points me in the right direction when the bug bites me and it's time to buy another light. My purchases are in spurts, dependent on what emitters are out there and what's new and exciting.

Thanks again for the nice welcome.

Cheers

:welcome:





I didn't post anything about factual inaccuracies.

Many ( even most? ) of the flashlight enthusiasts here have personal experience, however, with at least one light having drained a full battery sitting idle in ~ one month or less.



Charging a battery for one minute, once per month, would not solve that problem.

Some flashlight users here must exclusively rely on primary (non-rechargeable) cells, for any of a variety of reasons.

This, too, would preclude simply dismissing the concerns of even relatively "limited" parasitic drain.



I would hope that our flashlight experts here would not use their first post on a bioluminescence microplate reader forum to explain how mistaken they all were over there.

It sounds like you have a lot of technical knowledge, however, and hope you will stick around to share it with us here on CPF.

Perhaps you will even learn something here yourself ... cheers

 

[archimedes]

First and foremost, thank you for your kind welcome.

Certainly

What is required of the processor in a flashlight? Lacking specifics, but considering input, output and housekeeping tasks, I would say not that much. Wake up, take a look around, go back to sleep. That a turned-off flashlight would drain an 18650 in a few weeks is obscene, indicative of (at least) poorly written code....

Yes, I believe this was the general point that the OP was trying to make.

It is important to note (speaking for myself at least) that many of the particular flashlights with excessive parasitic drain use far smaller power sources than 18650.

Modern 18650 may have over 3000 mAh, but some of the problem devices have battery capacity of 500 mAh or less.

As you rightly note, these can reflect firmware issues, hardware problems, either or both.

 

[vadimax]

Thank you for explaining how it works.

I have some vintage lights (read incan from the 20's to the 50's) that drain the battery in some cases a few days.
Nothing electronic, just seemingly a circuit that never gets completely cut when sliding the switch to off. Some do, some don't. (I wonder if that may be the case to cause this thread.)

Being they aren't very bright anyway I don't figure them as emergency lights and store batteries outside the light(s).

With an old light there are two options: degraded isolating material or fine metallic dust from moving parts.

 

[vt2nv]

Hmm, I haven't considered that, and it seems reasonable. Cheers.

With an old light there are two options: degraded isolating material or fine metallic dust from moving parts.

 

[vadimax]

Hmm, I haven't considered that, and it seems reasonable. Cheers.

Yeah, if you see that dirt, most likely it is conductive

 

[vt2nv]

I just learned something new. Probably worth taking my older lights apart to clean their interiors. Maybe time to break out my trusty Fluke 8845A and take a serious look at the parasitic drain of the lights in my collection. I assumed that parasitic drain would be a non-issue, it looks like that was a flawed assumption.

Yeah, if you see that dirt, most likely it is conductive

 

[xxo]

One of the mil specs tests for the mx991U "moon beam" angle head flashlights involves checking the switch with a meter to make sure there is no current drawn when off.

 

[bykfixer]

Wow xx. I did not know that. But it makes as much sense to a soldier as cleaning his rifle.

I've restored dozens of old lights, part of which is achieving the least resistance practical. But it never dawned on me to check it while turned off.
:duh2:

 

[GaryF]

The Nitecore Pionerr / EA4 is another example of high parasitic drain. It would be one of my most used lights if not for the fact that it will be dead within 2 months even if I don't use it. And with 4 aa batteries in series, these deep discharges are hard on the batteries.

It's just poor, sloppy design. There are plenty of good examples out there, my Zebralights have parasitic drain, but it's so low that you would never notice it.

 

[markr6]

The Nitecore Pionerr / EA4 is another example of high parasitic drain. It would be one of my most used lights if not for the fact that it will be dead within 2 months even if I don't use it. And with 4 aa batteries in series, these deep discharges are hard on the batteries.

It's just poor, sloppy design. There are plenty of good examples out there, my Zebralights have parasitic drain, but it's so low that you would never notice it.

Exactly. Ironically, some of my "would be" favorite lights are the ones with high parasitic drain. Total bummer!

 

[xxo]

Wow xx. I did not know that. But it makes as much sense to a soldier as cleaning his rifle.

I've restored dozens of old lights, part of which is achieving the least resistance practical. But it never dawned on me to check it while turned off.
:duh2:

It was not a test used to see if the switches were kept clean, but a random sample test that they used to do on each batch of lights coming from the manufacturer to see if they are making 'em right, but it would probably be a good test for a old light during restoration.

 

[tatasal]

The Nitecore Pionerr / EA4 is another example of high parasitic drain. It would be one of my most used lights if not for the fact that it will be dead within 2 months even if I don't use it. And with 4 aa batteries in series, these deep discharges are hard on the batteries.

It's just poor, sloppy design. There are plenty of good examples out there, my Zebralights have parasitic drain, but it's so low that you would never notice it.

Yes, some Nitecore models are just notorious in extra high parasitic drain for I have them too, and yes, my ZL SC600 has, as an opposite, an ultra low parasitic drain that I just left for years and never worried about it.

Not until you have a light with horrendous drain rate and ruined a cell/s will you understand the significance of a light with very minimal drain.

It's just a PITA looking after those high drain lights...we are supposed to enjoy this hobby, and not become 'caretakers' of such poorly-designed offerings.

 

[18650]

Yes, some Nitecore models are just notorious in extra high parasitic drain for I have them too, and yes, my ZL SC600 has, as an opposite, an ultra low parasitic drain that I just left for years and never worried about it. Not until you have a light with horrendous drain rate and ruined a cell/s will you understand the significance of a light with very minimal drain. It's just a PITA looking after those high drain lights...we are supposed to enjoy this hobby, and not become 'caretakers' of such poorly-designed offerings.

Too many models. Too many people making excuses for Nitecore in a thread in the LED forum. High parasitic drain should not be a problem in a modern light but for Nitecore it is.