*SOLVED - Thank you!* Li-ion batteries going to 0.01 volts instantly - HELP!

[RichS]

I really need your help with this one! I haven't ever seen or heard of anything like this happening, and it's happening with one of my very favorite builds!

I have a 2x18650 Leef body (new) and an M3 head with a SW01 tailcap (thanks DM51). This light has worked fine up until today. I have used it several times with an MN11, and recently received an IMR-M3 to use with it. I was assured by Mark at LF that normal 18650 li-ions will work with it just fine, but not to use anything smaller. It's only pulling 2.4A, so no problem. I tested it out for a little bit - worked great - nice and bright with nice white color.

Today though, I went to test it out against my new M6 HO-M6R setup, and when I inserted my newly charged 18650 Ultrafires (4.05v) - nothing. I took them out, tested them on my multimeter and one of them showed full charge and the other one showed 0.1 volts! I thought - I'll never buy Ultrafires again and threw it in the trash. I put in another battery (Tenergy) with the good Ultrafire, same problem - no light. I again tested one of the batteries - 0.01 volts again. Then I knew I had a major problem.

I don't know what is causing this, but it seems the top battery (the one closest to the bulb) is instantly draining to 0 volts as soon as I screw together the light. Now after 3 batteries "fried", I took a chance and threw one back in the charger. Within minutes it was back up to it's full charge again. Was it just something with the protection circuit?? This setup literally worked perfectly a day ago, and today it went bezerk.

Any ideas at all? Here is my setup, and I took some pics just to see if any of you noticed anything wrong. I don't even know where to begin to look....thanks in advance for any help you can provide!

The light

The Problem - from fully charged to 0.01 volts!!

Inside of the SW01

Back end of the Leef battery tube

Back of the head with lamp inserted

Inside of the M3 Head

The MN11 lamp

The LF IMR-M3 Lamp

 

[carbine15]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

its not draining to zero, its protection circuit is kicking in. Thermal protection maybe? Only takes a second to reset the protection circuit by charging for a second.

 

[spencer]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

Maybe there's a short somewhere.

 

[mdocod]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

The Tenergy and UltraFire PCBs are very likely not designed to allow you to fire up the inrush current of a high power lamp like that. The instant near-0V reading is the PCB tripping access to the cell OFF because it thinks something is wrong. This does seem weird to me though as I know UF has some xenon flashlights that draw at least this much current and are designed to use these cells, hmmmmmm......

-Eric

 

[wapkil]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

(...)

Today though, I went to test it out against my new M6 HO-M6R setup, and when I inserted my newly charged 18650 Ultrafires (4.05v) - nothing. Was it just something with the protection circuit?? This setup literally worked perfectly a day ago, and today it went bezerk.

(...)

Any ideas at all? Here is my setup, and I took some pics just to see if any of you noticed anything wrong. I don't even know where to begin to look....thanks in advance for any help you can provide!

Have you tested this setup with different lamps after the problem appeared? I'm not sure if I understand precisely what parts are there in the light but it wouldn't hurt to start from eliminating the possibility of something shorting inside the flashlight (as spencer suggested). Maybe this new HO-M6R is faulty and shorts the battery? If it was the HO-M6R lamp fault other lamps should work ok.

 

[Moddoo]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

My ultrafire cells don't like high current either.
Similar problems with the protection circuits.

cough::junk;;cough

 

[RichS]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

All - thanks for the input. It makes total sense what several of you have said about the PCB kicking in and turning the cells off.

I must be looking at a short of some kind that is causing this, because it happens with both lamps - the MN11 and the IMR-M3. The MN 11 has been a lamp known to work fine with 18650s, and I've used it in the past with no problems.

So what could be causing the short?? I don't know where to begin to look, or even how to test to see if there is one. I know that the lamps are in good shape (the IMR-M3 is brand new), the M3 head and Leef tube are in mint condition (no missing anno, etc.), and the SW01 I got from DM51 looks in very good shape too.

As far as testing equipment, all I have is a digital multi-meter. Would I need something else to test this, or is there other troubleshooting that I can do? Boy - it's nice to have such ready access to experts in this field - thanks CPF!!

EDIT: I just thought of something - I have a couple of brand new MN10 lamps which draw only about 1.3 amps. If I tried this lamp and it still tripped the PCB would this confirm that there is a short somewhere?

Thanks again guys!!

 

[wapkil]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

(...)

So what could be causing the short?? I don't know where to begin to look, or even how to test to see if there is one. I know that the lamps are in good shape (the IMR-M3 is brand new), the M3 head and Leef tube are in mint condition (no missing anno, etc.), and the SW01 I got from DM51 looks in very good shape too.

As far as testing equipment, all I have is a digital multi-meter. Would I need something else to test this, or is there other troubleshooting that I can do? Boy - it's nice to have such ready access to experts in this field - thanks CPF!!

EDIT: I just thought of something - I have a couple of brand new MN10 lamps which draw only about 1.3 amps. If I tried this lamp and it still tripped the PCB would this confirm that there is a short somewhere?

Thanks again guys!!

I'm not sure if it's a good idea to proceed with testing the light with LiIon batteries if you suspect that there may be a short somewhere. The batteries have a protection circuit but I don't know whether it affects their future performance when the circuit is forced to intervene. Moreover if something goes wrong with the circuit, the current they are able to deliver will be really high and dangerous.

If in the same setup the batteries and the lamps worked until today, I don't see how they could suddenly stop to be compatible now (although strange things sometimes happen so who knows).

The tailcap when turned on should conduct current (i.e. short the circuit) so I would suspect it's not its fault if the problem is indeed in some shorting that makes it possible for the current to bypass the lamp.

I have no idea what could cause the short. If you know that the lamps are working correctly, the only possibility for the short I can see would be if the springs in the lamp touch when compressed. Maybe someone has another idea?

Or maybe after all it's not a problem with a short circuit. Were those Ultrafire batteries previously working correctly? Was it the Tenergy battery that read 0.01V in the second test or it was also an Ultrafire?

 

[RichS]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

I'm not sure if it's a good idea to proceed with testing the light with LiIon batteries if you suspect that there may be a short somewhere. The batteries have a protection circuit but I don't know whether it affects their future performance when the circuit is forced to intervene. Moreover if something goes wrong with the circuit, the current they are able to deliver will be really high and dangerous.

If in the same setup the batteries and the lamps worked until today, I don't see how they could suddenly stop to be compatible now (although strange things sometimes happen so who knows).

The tailcap when turned on should conduct current (i.e. short the circuit) so I would suspect it's not its fault if the problem is indeed in some shorting that makes it possible for the current to bypass the lamp.

I have no idea what could cause the short. If you know that the lamps are working correctly, the only possibility for the short I can see would be if the springs in the lamp touch when compressed. Maybe someone has another idea?

Or maybe after all it's not a problem with a short circuit. Were those Ultrafire batteries previously working correctly? Was it the Tenergy battery that read 0.01V in the second test or it was also an Ultrafire?

Good point wapkil. Maybe I'll wait to try the MN10 and see if anyone else has any other suggestions first. I definitely don't want a li-ion explosion on my hands....

To answer your questions - yes, the Tenergy battery also read 0.01v when I tried it. So, it happened to both Ultrafire batteries and one Tenergy battery (3 in all). All batteries worked fine previously and each only had a few cycles on it. This is definitely either a short curcuit in the light somewhere, or possibly both lamps suddenly became too much for these cheaper protected li-ions to handle. I just have a hard time believing that though - each lamp is only pulling ~2.5 amps, and you can safely push li-ions around 2C, or around 4.4 amps (although the protection kicks in around 3 amps on these cheaper cells I believe).

 

[seaside]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

A freind of mine recently told me the same thing. It was ultrafire 3000mA. The difference is, one his is a brick out of envelop. The other one works fine.

What bothers me is why it is 0.1V, not 0.0V if proctection kicked in? It's not his DMM reading wrong, and quick jolt from charger can't bring it back to life.

I'd like to know what cause this, so that I can tell him how to fix or... where to put it... flashlight or trash can.

 

[RichS]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

A freind of mine recently told me the same thing. It was ultrafire 3000mA. The difference is, one his is a brick out of envelop. The other one works fine.

What bothers me is why it is 0.1V, not 0.0V if proctection kicked in? It's not his DMM reading wrong, and quick jolt from charger can't bring it back to life.

I'd like to know what cause this, so that I can tell him how to fix or... where to put it... flashlight or trash can.

Well, in my case, each cell instantly came back to life once on the charger, so it must have been just the PCB in my case. Also, my multi-meter actually did jump back and forth between 0.0v and 0.01v when I tested the cells. Probably just too close for MM to read. In your friends case, it sounds like that cell is destined for a return or the trash can.

 

[wapkil]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

Good point wapkil. Maybe I'll wait to try the MN10 and see if anyone else has any other suggestions first. I definitely don't want a li-ion explosion on my hands....

(...)

I just have a hard time believing that though - each lamp is only pulling ~2.5 amps, and you can safely push li-ions around 2C, or around 4.4 amps (although the protection kicks in around 3 amps on these cheaper cells I believe).

If the lamp pulls ~2.5A, its resistance should be around 3Ohm. You should be able to measure it with your DMM. While waiting for other ideas you may measure the lamps (setting your DMM to the lowest resistance measurements - 200Ohm in your picture). You can try to compress the springs while measuring, put the lamp inside the flashlight, etc. If the resistance drops near 0, you'd know there is a short circuit.

EDIT: all these measurement of course have to be done without the batteries.

 

[Bullzeyebill]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

Go ahead and use it with your MN10. There should be no problems.

Bill

 

[ma_sha1]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

Well, at least you have protection on 18650.
I just fried 2 DX C Li-ion due to short out.

Two battery together, when short happens, one die & one live.

I finally figured out what's causing it but I can't bring the battery back to life as it's not protected. Got to wait for a month again unti new battery arrives.

Does anyone know if AW IMR C li-ion have short protection?

 

[Mr Happy]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

If the lamp pulls ~2.5A, its resistance should be around 3Ohm.

No, not so. The cold resistance of a lamp filament is typically less than one tenth of the normal operating resistance. So the resistance of that filament is likely to be in the 0.1 to 0.3 ohm range. Basically, any high powered lamp is a short circuit when first connected to a power supply.

 

[wapkil]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

No, not so. The cold resistance of a lamp filament is typically less than one tenth of the normal operating resistance. So the resistance of that filament is likely to be in the 0.1 to 0.3 ohm range. Basically, any high powered lamp is a short circuit when first connected to a power supply.

Thanks. I stand corrected. I had an impression that something may be wrong with my advice but to check it I measured and old small bulb I had lying around. It was 1.7 ohm so I figured that what I remembered about not measuring the bulbs was wrong. I should have tried a 20W halogen bulb instead to see that indeed it has 1/10 of the operating resistance.

 

[Packhorse]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

its not draining to zero, its protection circuit is kicking in. Thermal protection maybe? Only takes a second to reset the protection circuit by charging for a second.

Thanks!! You answered this question here!

 

[spencer]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

Maybe hook the batteries straight to the original bulb. Use some wire and some magnets. It that works then its a short.

 

[RichS]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

its not draining to zero, its protection circuit is kicking in. Thermal protection maybe? Only takes a second to reset the protection circuit by charging for a second.

The Tenergy and UltraFire PCBs are very likely not designed to allow you to fire up the inrush current of a high power lamp like that. The instant near-0V reading is the PCB tripping access to the cell OFF because it thinks something is wrong. This does seem weird to me though as I know UF has some xenon flashlights that draw at least this much current and are designed to use these cells, hmmmmmm......

-Eric

My ultrafire cells don't like high current either.
Similar problems with the protection circuits.

cough::junk;;cough

Right you were!! It was the PCB kicking in, and apparently instead of just not lighting it up, it disabled the battery.

When I got home I tried the MN10 - fired up perfectly with no issues.

Then, I cautiously tried the MN11, but I tried a different tailcap (z58) just to see if it would work with one part replaced..it worked. Then I tried the SW01 again, and for some reason it caused the PCB to kick in again. But once I touched the DMM leads to the battery, it went from 0.01v right back up to 4.04v??? I was thinking my $115 tailcap was bad at this point... Since the battery reset back instantly, I put it right back in and tried again with the SW01 - worked fine this time for whatever reason. I then tried with the IMR-M3 and it also worked, but I noticed that a couple of times it didn't light it up with the first press or twist.

Conclusion - the MN11 and IMR-M3 are right at the PCB limits of the Ultrafire/Tenergy, and cause the PCB to kick in or shut down the battery. I'm also thinking that the SW01 has something a little different to the build that may cause the PCBs to sporatically work/not work. In the end, it's really the batteries PCB circuits being on the edge with this draw that is causing the problem.

Fix - use a lesser bulb or AW batteries (which I should have done in the first place...)

Thanks for all your help in solving this!!

 

[mdocod]

Re: Crazy problem with li-ion batteries going to 0.01 volts instantly - HELP!

The Z58 probably has higher resistance than the SW01, resulting in a reduction in inrush current and slightly reduced running current, just enough to make the difference.