The Official Zebralight Thread .

[WalkIntoTheLight]

FWIW, I find the cold H1 problem happens less with a 30Q. However, that's based on very little data (I normally use a VTC6 or GA), so it may be pure coincidence. Next time I go for a long walk in the cold, I'll use a 30Q and see what happens.

I recall seeing some info on the battery sub-forum about 30Q vs. GA in extreme cold. I can't recall the exact info, but I think it concluded that a 30Q did way better (in terms of watt-hours). However, I think they were doing run-time tests while constantly force-freezing the cells, so the cells couldn't warm up. But, that may be a good analogy for the H1 start-up when cold.

 

[xevious]

That was my first thought, though I tried with with 30Q, VTC6, and Sanyo GA. At least the first two (high drain) cells should work in the cold.

Also, the behavior is different than a cell that can't provide enough current/voltage. When I use an old low-drain laptop cell in the cold, the behavior is that the light very quickly drops from H1 to low. It doesn't go out. This is the same behavior when LVP kicks in normally at room temperature.

The behavior I'm seeing is that the light goes from H1 to off, in a second or less. However, it's a strange "off" state. Rather than a single-click to turn back on the light, I have to click it once (presumably to really turn it off), then click it again to turn it back on. So, it takes 2 clicks to turn it back on, rather than 1 click.

I'm not sure what behavior the light does if the battery truly goes below the 2.8v low-voltage-protection. Has anyone tried this? I guess maybe it's not possible to test, because you'd have to change the battery to turn it back on. I've tried to see what happens, but I get bored of watching the light in low for hours sitting around the 2.9v level.

All that said, I'm still open to the idea that it's a battery issue. I know that cold batteries don't work well, and might not be able to supply the required current to the light for max output. If the light simply dropped to low, yeah, I'd 100% agree it's the battery. But to shut off completely... sort of?

I suppose it's possible that the battery voltage sags so low, so quickly, when cold, that it triggers the light to go into LVP shut-off mode rather than simply step-down. But, I'm not sure if a high-drain cell would sag so much under load, even at -10C.

I don't think my batteries are fakes. I got them from Illumn. They're about a year old.

It would be interesting to keep one duplicate of the same battery and stash it in your pocket, near body heat. When the light acts, up, swap batteries. See if it still happens.

 

[WalkIntoTheLight]

It would be interesting to keep one duplicate of the same battery and stash it in your pocket, near body heat. When the light acts, up, swap batteries. See if it still happens.

Hmmm, yeah, freezing light + warm battery. Good idea. I'll give that a try and see what happens. Supposed to be -20C in a couple of days, so that should be a good test.

 

[Derek Dean]

So, while I have really been enjoying my new SC700d, I've also been contemplating what light I'd like to see next from Zebralight. For me, the SC700d is a light caught between two worlds, it's not small enough to fit in a pants pocket, but it's not large enough to feel like a full sized light.

Maybe what ZL needs is a Massdrop light..... you know, the SC8XX, running the XP 70.2 LED with a 26650 cell in a much larger body with enough mass and fins to keep it running cool at close to full output. Give it a plug in rechargeable circuit so nobody has to mess with taking the cell out, and keep the same ZL UI...... then make 3 videos, one showing how useful it is to have the incredibly versatility of the ZL UI and 3 programmable setups. A second video showing basic operation, and a final one showing advanced programming.

What do you'all think? Am I off the beam here?

 

[neutralwhite]

hi, - does ZL do better in the Low Modes Than HDS?.
ZL more efficient?.
thanks.

 

[Mr. LED]

hi, - does ZL do better in the Low Modes Than HDS?.
ZL more efficient?.
thanks.

Zebralight is a lot more efficient in the lower modes than HDS.

 

[neutralwhite]

so ZL could now be really "the light that gets you home"
?

Zebralight is a lot more efficient in the lower modes than HDS.

 

[WalkIntoTheLight]

so ZL could now be really "the light that gets you home"
?

Heh, well, you'll get home with a lot more cash in your pocket, for sure.

 

[maukka]

It doesn't take a week to drain a 16340 in an HDS on minimum level (about 3-4 days). With a ZL and an 18650 you will be counting months or a year even. And you still have money for a cab.

 

[WalkIntoTheLight]

Hmmm, yeah, freezing light + warm battery. Good idea. I'll give that a try and see what happens. Supposed to be -20C in a couple of days, so that should be a good test.

Groan. Tried to reproduce the issue with both the SC600w HI and the SC64 HI, in windy -20C temperatures last night. Tried for 3 hours, couldn't reproduce. I tried freezing light + freezing battery, freezing light + warm battery, and warm light + freezing battery. Tried with VTC6, 30Q, and a low-drain 22H.

All cells were charged to 50%, with a resting voltage of 3.75v. I tried 8 cells in total!

The high drain cells worked great. Only the low drain cell had issues when it was frozen. The lights would come on in max, then quickly drop to low, as expected.

I also tried in -10C conditions, and all cell types worked fine on max, even the low-drain.

For the shut off from max issue, it must be gremlins. It only seems to happen when I'm not trying to make it happen. I thought for sure that a windy -20C night for 3 hours would be enough. I've certainly had it occur in less time, in warmer conditions (-10C), and be easily reproduced when it happens. I don't know what the trigger is.

 

[ven]

. in warmer conditions (-10C), and be easily reproduced when it happens. I don't know what the trigger is.

Damn...............warmer conditions -10

 

[xevious]

For the shut off from max issue, it must be gremlins. It only seems to happen when I'm not trying to make it happen. I thought for sure that a windy -20C night for 3 hours would be enough. I've certainly had it occur in less time, in warmer conditions (-10C), and be easily reproduced when it happens. I don't know what the trigger is.

Given the temperatures where you are at, I wouldn't be surprised if it is gremlins! :candle: How much of the year is it above freezing at night in your neck of the deep dark woods?

 

[WalkIntoTheLight]

Given the temperatures where you are at, I wouldn't be surprised if it is gremlins! :candle: How much of the year is it above freezing at night in your neck of the deep dark woods?

About half the year is above freeing at night. Unfortunately, that's also when the nights are short!

However, the issue really only starts to become a problem below about -10C. And since it's only a problem on max, there's no issue for any of my usual modes. But, it's still annoying.

I did have the issue repeat again while I was out walking a couple of nights ago in cold weather. Very easy to reproduce. And, I figured out that the driver is still turned on, it's only the LED that doesn't get lit. For example, I can double-click to go back to a lower mode, or I can click-and-hold to get into a low mode. Apparently, the problem is that the LED isn't getting power, but the flashlight still thinks it is. Weird.

Once I give that LED some warmth (by using a lower mode), it works on H1. But trying to turn on H1 from off, after letting the light get cold for a few minutes, it's about a 50% chance it will quickly go dark.

All that said, I have been unable to reproduce the problem in controlled conditions (freezer, or letting it sit outside in the cold). It's only ever been an issue when out walking, during "normal" use. Maybe there's another factor besides cold, such as battery contact issues due to the light getting jostled around when walking?

Does cold increase resistance between contact points?

 

[likethevegetable]

Does cold increase resistance between contact points?

Theoretically, metallic resistance decreases with temperature drops. But

Maybe the cold is causing the pogo springs to contract and it's losing contact pressure?

 

[neutralwhite]

sounds so. what does ZL say on this?.

Theoretically, metallic resistance decreases with temperature drops. But

Maybe the cold is causing the pogo springs to contract and it's losing contact pressure?

 

[markr6]

I still feel like it's a random bug. Mine turned off at room temp as much as it did outside in the cold.

 

[NPL]

The Zebralight family is growing.
Thought I'd share this photo I took. Notice the anodizing colour between sc600w Hi and sc600w plus? Good way to tell them apart without looking at the emitter.

 

[WalkIntoTheLight]

The Zebralight family is growing.
Thought I'd share this photo I took. Notice the anodizing colour between sc600w Hi and sc600w plus? Good way to tell them apart without looking at the emitter.

That's odd. My 600w HI and 600w Plus are almost the exact same shade, both dark. Perhaps the Plus is very slightly darker, but it's really close. Mine are both the MkIV model.

 

[markr6]

Mine have all been the dark gray, very consistent between about 2013 and now with the exception of the SC700d. As mentioned before, the new stock of aluminum from China instead of Michigan is apparently being used for all recent lights. Inconsistency is my biggest pet peeve...but I'm gonna have to get over it since I ordered another SC700d!

 

[emarkd]

Huh, I missed that they swapped aluminum suppliers. Zebra used to make a big deal out of using US metal. Do we know what made them change, or is it assumed to be money?