This is an extension of my previous question in this thread...
At some point, I THINK I ran across a thread whereby someone used 1x battery, versus the 2x RCR123A, in one of the Survival Lasers (it was EITHER a 405 or 445, I forget which). Logically the 1x battery was PROBABLY a 18650.
I can't seem to find the thread... it seems to me that it was just a short post in a long thread.
ANYWAY... does anyone have any info / experience on using 1x 18650 versus 2x RCR123A in their Survival 405 / 445? (FIRST of all, will 1x 18650 FIT and make sufficient electrical contact... EDIT oops sorry yes it occurs to me that it WILL, unless the innards are spaced differently than in an SL-660 red).
Here are the default stats from Gary's website:
Optical power output is 500mW +/- 50mW with the standard lens, 650mW +/- 50mW with the G-1 lens.
Optical power output is 1,150mW +/- 150mW with the standard lens, 1,265mW +/- 150mW with the G-1 lens.
I.E; Thanks... I appreciate it... that will give me data for the 445.
(the air conditioning went out in my apartment this afternoon, inside temp is approaching 80 degrees... have to log off soon and STAY off until I can cool my apartment again... might not be able to respond till ~ monday or so)
The Driver that is Used in the SL-V-SL-B and SL-II is perfectly Fine Off 2x 18650.
There will be no More Heat added because you use 2x 18650 instead of 2x 16340.
They are Both 3.7v cells and at fully charged they are 4.2V.
So the Voltage stays the same Between the 2 different types of cells you use.
When Stacking batteries You dont gain double the capacity you only gain double the voltage. So for Example if you have 2x 18650 that are 2600mah the Voltage will be 8.4V when they are both fully charged and the Mah will stay the Same at 2600mah.
But because an 18650 alone has more capacity then a 16340 you will gain lots of run time. 3-4 times more run time.
To answer your question on using 1x 18650.
Yes You can Do this with the 445nm laser only. It will power the 445nm Up to <~500mW.
THis will not damage the laser.
However in the SL-V that i just tried Right now, it will not power it. Only to ~10mW.
Maybe when close to the lower lasing thresholds (due to less current from 1x versus 2x batteries), the minor diode-to-diode variations become more pronounced between lasers (even with the same model). Oh well, was hoping for more precision, but that's OK. I'll just know that 1x battery = considerably less mw's (But still not eye-safe, of course. Maybe less tendancy to burn holes in walls )
If its not a boost driver which im sure its not than thats why output drops so much. The 445nm requires 4V and drivers are not 100% efficient and even fully charged 4.2V li-ions are not 4.2V under load so your effectively making your current limiting driver a voltage limiting driver since your not providing enough voltage. This means that your output will GREATLY depend on your batteries charge level since a small change in voltage equals a large change in output. I wouldnt recommend it since its not designed for that.
as far as 2 cr123a vs 2 18650s thats easy. They will be the same. If you test it you may find some difference but that will come down to the individual batteries. It could go either way depending on your batteries. This will hold true unless the driver is set above the discharge rate of the smaller battery set.
I'm a little late to this thread. But yes indeed you can run at least the 445 on a single 18650 for a much lower output. A couple of things to keep in mind though. Many (most?) 18650's were harvested from laptop battery packs and don't have a "nub" on the positive end. This makes it hard for it to make contact in the SL. I put a small solder blob on mine and it works fine. Gary has mentioned once before that the voltage threshold for using a single 3.7V battery (18650) are rather tight. In other words, be sure to charge the thing fully if you can't get it to lase. It might lase at 4.0V but fail to at 3.9V. You won't hurt the laser if you use a depleted battery in it though. I also find that I have to adjust my tailcap (either tighter or looser) with a single 18650 battery.
I'm sure this also applies to the 405 but I don't have direct knowledge of this.
Did another test just now... same laser as before. First tested with the same cr123's as before... very similar result 1076mW peak.
Let the laser rest for two minutes and put in a freshly charged tenergy 18650 battery:
I'm rather surprised... again. I really thought I'd be getting around 200mW.
Since this is the lowest power 445 spot I ever looked at, I decided to look at the dot from from about 4 feet away on an off white wall, and an angle, without goggles. Not sure why, but for some reason I just don't handle 445nm indoors well I guess... even at low power, and not focused, I still saw yellow afterimage for a few seconds. Very weird, I only notice this with 445s.