Questions about the Tomahawk LE

Hello,

I just received the Tomahawk LE and I'm quite happy with it.

I've been using RCR123's and am only getting 75 minutes of runtime as apposed to the advertised 90 minutes. Is that common using rechargeables?

Also when the battery wears down, the light goes out without any warning at all. Is that common? Also, I read that the LED's would still work after the white light goes out. Mine does not.

The lower runtime and abrupt cutoff are qualities of using protected rechargeable cells. I don't know about your last question.

Yeah, it sounds like your protected battery shut down. After that, nothing will work on your light. You should always keep a backup primary CR123 on hand. Charge your RCR123 after you think you have used your light for more than half it's 75 minute life.

RCR's have ~700mAh while a primary has ~1300. But due to higher voltage, an RCR should have about 75% power capacity of a primary.

sdl said:

...Also, I read that the LED's would still work after the white light goes out. Mine does not.

Click to expand...

Blindasabat said:

Yeah, it sounds like your protected battery shut down. After that, nothing will work on your light.

Click to expand...

I have an EagleTac P10C that I'm using with Chinese generic 750mAh protected 16340s I bought from Lighthound. When the cell runs down on high and the protection abruptly shuts it off, all I have to do is click the switch off, twist the head to low, click the switch back on, and the light works for awhile longer. It seems the cell resets itself.

I have UltraFires and TrustFires that don't act this way (I have to put them in a charger to reset them), maybe I lucked-out getting these from Lighthound . I don't have any AWs in 16340 size, does anyone kow if they reset themselves?

Would I get longer runtimes with unprotected batteries? What are the drawbacks of using unprotected batteries? FYI, I'm using AW's WF-139 charger.

You will not necessarily get longer runtimes with unprotected cells, but what you won't get is the abrupt shutoff, leaving you in the dark (possibly dangerous, especially for LEO or military; a pain in the *** for most of the rest of us); instead they will start to dim, letting you know a battery change is needed.

The biggest drawback of using unprotected cells is when recharging them; if not handeled properly, they can be VERY dangerous (I strongly suggest reading up at BatteryUniversity, as well as doing a search here on CPF for "battery safety"). The second drawback of using unprotected cells is that if you don't change them as soon as you notice them start to dim, they can become too deeply discharged, and rendered useless (will no longer accept a charge).

But if your 139 is a newer one (5V open circuit across terminals, not higher) you can recharge these cells relatively safely (especially after reading up!); just make sure you use your DMM to test them before, during, and after recharging them. Before attampting to recharge them, make sure the resting voltage is at least 2.5V! The 139 is supposed to disallow cells to start recharging if they're below that, but I wouldn't trust it. Next, when one of the 139s indicators turns green, remove that cell and check its voltage; it should be no more than 4.2V, but will probably be less, usually around 4.08~4.15V. When charging two cells at a time, I leave the first one that turns gren out of the charger until the second one does as well, check it, let it rest for about ten minutes, then reinsert both cells to top them off to 4.2V. During this last step, I check both cells frequently until one, the other, or both reach 4.2V; then rock 'n' roll! :thumbsup:

Lastly, I'm not sure, but your Tomahawk might benefit from AW's new safe chemistry unprotected cells. Lights with high current draw actually DO get longer runtime with these cells. You can use the above link and post a question in that thread abuot your exact light, and if AW can't answer it himself, maybe someone else can, especially if you find out your Tomahawk's curret draw and include it in your question.

Hope this helps, Tony

A quick video I threw together running thru the different lights and the strobe feature enjoy!

http://www.youtube.com/watch?v=qMZCswxSWGs

Naked2 I am not sure you want to keep doing that to those RCR cells. When you trigger the protection circuit you should take them out and pput them on the charger and get them back up to full as soon as you can. Protected cells are not invincable because of that protection circuit and pushing them after it is tripped on low is gonna further drain them and shorten the overall life of the cells. (not an expert here just regurgitating what I have been told

When I first got into high powered flashlights, I used to spend $10~12 per pair of CR123As, and throw them away when depleted. If I only get 250 cycles instead of 500 cycles out my RCRs, I don't mind. Besides, I only paid $20 for ten of them, and haven't had to throw ANY of them away yet.