1.4A Boost Driver Runtime with 16340 Battery?

[IsaacT]

So I purchased two of the nice, compact MS-V4 hosts from Sinner and have been planning to make one a 520nm laser and the other a 635nm laser. And while I think it could handle the heat from the Mitsu 500 (Sinner said it handled a 1.2A M140 diode easily), I have begun to worry about the runtime.

On the surface, (mAh/current)=Hours

The mAh rating on my AW 16340 batteries is 550mAh. So (550/1400)=0.39

.39 x 60 = 23.5 Minutes

But, during a fast discharge, I have read that you are looking at roughly half the capacity, so

23.5 x 0.5 = 11.78 Minutes.


Is my math correct? Would I be looking at an 11 minute laser? Maybe worse? Should I go back to the drawing board?


Thanks,
Isaac

 

[Blord]

It is correct if the driver draws 1.4A from your 16340 cell. The small cells can't maintain the high current draw for long. These are not 26650/32650 cells.

 

[cheech226]

the math looks ok isaac. are you going to put a multimode red into that nice v4? i see you don't own a mm red by your sig. have you seen how horrible (imo) the beam looks with these diodes? such a nice sleek host cries for a single mode diode.
edit: just saw it was a boost drive, so it will draw more than 1.4A from the battery.

 

[IsaacT]

That is true, maybe I will get a 635nm single mode for it. I love the beam on the multimode diodes but I want a decent runtime. Also the conical shape of the focus adapter would look better with a single mode.

 

[Eradicator]

That is true, maybe I will get a 635nm single mode for it. I love the beam on the multimode diodes but I want a decent runtime. Also the conical shape of the focus adapter would look better with a single mode.

The single mode 635s are surprisingly bright, a really great beam, mine at 120mw is very bright, and you can see the dot on objects farther away than any other laser I have owned. Just an awesome tight beam and low divergence, I can easily see the dot on a stand of trees over a mile from my house around dusk. Any earlier than that its too bright out too notice.

I think my 120mw single mode 635 looks almost as bright as my 450mw Multimode 635 honestly, with a way nicer beam.

 

[BShanahan14rulz]

with a boost, you will be pulling more amps towards teh end of your discharge. Be mindful of the maximum safe discharge for your desired cell. :san:

 

[IsaacT]

I didn't think about it, but it isn't a boost driver. IIRC DTR uses a Linear driver with them and recommends one cell. But still....too short of a runtime.

 

[sinner]

My 1.5A Xboost M140 build runs perfectly fine for about 4-5 minutes with fully charged AW 18350 Battery.. Then the boost driver kinda struggles to get the full current draw and the output falls from 1.5W to just below a ~1watt and after a few second starts rising upto 1.35W thats when the little sink is a little too warm..

What 16340 you're going to use?

 

[IsaacT]

AW 16340 batteries 550mAh

 

[sinner]

It would work, like i said.. not stable for long !