Help with Zebralight SC600

So yesterday morning, I walked the dog early and my SC600 would not work in the high mode. It lit for a fraction of second and shut off. (I hadn't run it for anywhere near the 2 hr claimed run-time.) It worked in medium and low. It then occurred to me that maybe I should program 300 or 200 lumens as the second high mode so that when the 750/500 runs out, I will have something brighter than medium mode to use.

So I then put in another charged battery (both were Ultrafires), programmed the second high mode to 200 lumens, and turned the light on high and stood it on the tailcap. It dimmed to 500 lumens after about 5 minutes as expected, but then shut off completely after exactly 56 minutes. At that point, I couldn't even use the 200 lumen second high program, but could use the low and medium levels.

Does the fact that I am getting run times of less than half the published run times for 750/500 mode and that, once I no longer have sufficient battery strength to run at 750/500 I cannot access the 200 lumen mode programmed into H2 suggest that there is an issue with my flashlight or my battery or both?

Sounds like a battery issue to me. The runtime tests that ZL did were based on a Panasonic 2900 mah 18650. Are you using a 2900 mah battery? Is it an old or a new battery? Ultrafire is not one of the preferred brands around here. I'd recommend an "AW" brand 2900 mah 18650. The AW battery is truely 2900 mah unlike other brands out there claiming 2900 or 3000 mah capacity.

Kind of a pain to get a new battery for this issue, but it looks to be the most logical problem. If the problem persisted even with a quality battery like AW then it would be an issue with the light.

Ultrafire 18650 have been "measured" to about 1400mAh (although they state 3000mAh).
Try something better, there are quite a few brands
- even salvaged cells from a Laptop could give you more "stamina" (they usually are Panasonic / LG / Samsung / Sony, at 2200 or 2600mAh)

It's a new Ultrafire 3000mAh. I also have some new Trustfire 2500 mAh batteries. Are those any good, or should I just suck it up and spend the money for some AW's? I've also got one or two old laptop batteries around somewhere - I'll do a search and see how one goes about salvaging them...

AlonzoMosely said:

should I just suck it up and spend the money for some AW's?

Click to expand...

AW, Redilast, XTAR and the ones from the Laptops....

AW's work great in mine. My AW's all measure around 2550-2600 mah (running down to 3 volts at 500mah drain). You can take them down further for a bit more power but I don't like to do that.

AlonzoMosely said:

It's a new Ultrafire 3000mAh. I also have some new Trustfire 2500 mAh batteries. Are those any good, or should I just suck it up and spend the money for some AW's? I've also got one or two old laptop batteries around somewhere - I'll do a search and see how one goes about salvaging them...

Click to expand...

I think the most likely issue could be the battery. The ultrafire 3000mah are some of the worse ultrafire batteries around. They have a bad reputation, and a lot of them just seem to be recycled cells. e.g:
http://www.candlepowerforums.com/vb/showthread.php?316888-Fake-Ultrafire-18650-battery-warning

Try some batteries that are based on quality cells. AW 2900, redilast 2900/3100, callies kustoms 3100 are based on panasonic NCR batteries.
I think xtar 2600mah and AW 2600 is based on sanyo batteries.

Also look up an online store hkequipment; they sell some unprotected 18650 made by panasonic and sanyo. If you using an unprotected cell, make sure you have a good charger, a torch that has cut-off protection, a DMM and read up on li-ion safety.

Ultrafire & Trustfire are not that great. Stick with AW and/or Redilast. Those are the only two brands I'd trust.

Yeah Ultrafire are junk. Buy good batteries that should solve it I imagine.

Thanks everyone, just ordered some AWs. The linked thread on the Ultrafires is rather scary...