UltraFire 1-AAA ok with 3.6V Li-ion?

Can I use a 3.6V Li-ion AAA with my UltraFire W-602C? Thought I read somewhere that I could. Done the searches, but can't find the definitive answer.

My UltraFire is useless with alkalines or Ni-MH since it won't restart after even just a few minutes of use.

Also, how do you protect the 3.6V batt since the light isn't going to cut out until 1.2?V?

I just received a 1aaa ultrafire from fifth/unit. There site stated you could use the 3.6 li-ion on it. When I put it in the light it lit for about 3 seconds and blew out. I contacted fifth/unit and they told me the 3.6 would work fine.
I told them the one I just received from them blew out. So I just got an e-mail from them after a week, to send the 1 aaa back to them. However since than they have changed the wording on that light, and now it does not say for sure if you can use the 3.6 battery. When I finnaly get a replacement, which looks like it could take them a month or more to send it. I would only use a reg. aaa in the new one.
PS: There wording wil I got the light stated [It would fly on the 3.6 battery] It sure did blew right out.

Ron, I just got an e-mail from Fifth/Unit about the Ultrafire w-602C AAA flashlight. Kai-Lam told me these lights work fine on the 3.6 Volt li-ion battery.
But being it is running at a higher voltage, it would get hot after 10 minutes of running. So just cycle the duty of it and it will be fine.

He also told me he is sending me a replacement right away. I have purchased several other lights from Fifth/Unit with very good results, so they seem like a good company to deal with. I just ordered a 3 watt cr2 mini light from them, waiting to get it. For sure there prices are very good.

That's good news. Actually I've already tried the 3.6V Li-ion in my UltraFire and all is going well. It's just that the more I thought about it the more I figured I better check. I really shouldn't worry, since I consider mine to be useless with standard AAAs. It wont restart if the voltage drops below 1.27V. See this thread.

Still wondering how to protect the batt from being run down too far though?

Been running mine on them for months now. No problems.

Also, AW is doing a great deal on two Li AAA cells and an AAA Nano charger for $15 worldwide delivery inc.

Here,

https://www.candlepowerforums.com/threads/79847

Picked up my Li AAA/AA charger from Fifthunit . Two batts and the charger, which can charge 1 or 2 batts at a time, were under $14. Ordered some other odds and ends from them as well. Pretty reasonable and quick delivery, considering it comes all the way from Hong Kong.

I'm concerned that when using a lithium ion cell in the Ultrafire AAA (WF-602c) the battery will too easily be discharged below 3 V, given that the boost circuit in this light works down to 1.2 V or so.

Is the light noticeably dimmer when the lithium ion cell falls below 3 V? Would a non-flashaholic be able to reliably turn the light off before the battery is damaged?

Has anyone tried bypassing the boost circuit with a wire or a resistor? With the battery driving the LED directly, the brightness will drop to near zero at around 2.8 V, prompting the user to turn the light off before the cell is damaged. Though I wonder if the light's output curve would be too steep when driven directly.

I've had mine for several months, and only use it occasionally. It gets very hot when run for more than a few minutes at a time, so I use it when I need to mouth hold an intensely bright flood type light for a short period. It will lose intense brightness...almost suddenly, and that's when I replace the battery. Although, there's probably several minutes of reduced brightness or possibly hours, I just change out the battery and haven't experienced a single problem.

Although still quite bright, Its nearly useless for intermittent use with a Nimh.