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1 amp from trustfire 16340s ?






BShanahan14rulz

BShanahan14rulz

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1 Amp is pushing it. These are approx. 600mAh cells, and using the general rule of thumb of 2C=max discharge in amps, 1.2A is theoretically the highest you can go.

If you really really need high discharges, there may be some IMR 16340's available now. I know AW carries some 550mAh IMR16340's. I believe he claims 4A max discharge on those.

Edit: but I really ought to answer the original question, since that affects the reader's judgement on the accuracy of the post. In this case, I have not tested these cells, so I'm just going off of other experiences and others' experiences.
 
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Benm

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The IMRs sound like an interesting option - i was considering to power a 445 off two 16340 cells. The only ones i have around here are the trustfires, but i could always get better ones if required. It would just suck to build the thing and then find out the batteries don't support its current draw.
 
00Giorge

00Giorge

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Benm said:
Just wondering - has anyone here tried to pull about 1 amp of current from the trustfire 16340 cells like these? DealExtreme: $5.21 TrustFire Protected 3.6V 880mAh 16340/CR123A Batteries (2-Pack)

I see a reviewer managed to get a good deal of charge out of them at that dischrage rate, but would you guys think its reliable?
Click to expand...

I use these bats in my 445, they last quite a while. I don't have an lpm
so I don't know what the out put is. It is just like the one that Jerry did a review on http://laserpointerforums.com/f52/review-170-00-445nm-lvyi-electronics-laser-55665.html

hopefully this helps!

Jeff
 
Benm

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I'd like to see the discharge curve of those ultrafires. They look almost identical to the trustfires, and i doubt there would be much difference between them. If you could discharge analysis at 1 and/or 1.5 amp current draw that'd be great!

I have a 445nm diode running off 800mA with a single IMR cells. I get about half an hour of lifetime.
Click to expand...

I'm considering using 2 in series, with a linear driver... so that would probably result in about half the current draw.
 
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csshih

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I'll do a 1 amp draw because the draw probably won't be too high if there are 2 on a buck driver.. be back in about 30 minutes!

edit:

Oh Jeez!

I did the test... and the cells did horrifically..

then I checked dealextreme.. -- I ordered these cells 10/18/2008 - almost 2?!! years ago..

SS-2010-10-06_04.12.27.png


I haven't used these particular cells in a long time....


it appears internal resistance is insanely high now!

when the discharger released the load from the cell, it hopped up to 3.6ish -- then climbed all the way up to 3.94 V while I was making this post.. so this particular ancient cell won't do well direct drive...

edit:

super high internal resistance.. still functions OK at low draws.. interesting..
 
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Benm

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Wow.. that plummetted to under 3 volts within 60 mAh of discharge?!

Perhaps its their age and/or lack of use thats causing this indeed, they aren't -that- horrible when you get them fresh. I wonder if they recover with a few cycles.
 
csshih

csshih

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er.. so very sorry.

uh... while cycling the darn cell.
..it decided to start leaking on me.

interesting experience, whatever in the cell has sickly sweet smell.. I hurriedly stopped huffing and tossed out the cell, of course.

sorry about that!
 
Benm

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Good to know that they can fail like that! I guess it was shot before your attempts, but luckily nothing really bad happened. Perhaps these cells arent all that good for demanding applications, but at least the IMR cells would provide a solution in the same form factor if required.

I suppose it would be okay to design a powerful 445 powered by 16340s, even if the old trustfire cells dont supply enough current to make it work.
 
csshih

csshih

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I can still give a prod at the other cells if you like.

I feel bad that the cell I had was bad, eek!
 
BShanahan14rulz

BShanahan14rulz

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Benm said:
I'm considering using 2 in series, with a linear driver... so that would probably result in about half the current draw.
Click to expand...

Yeah, with a linear driver, usually you can assume that the current through the diode is the current being drawn through the cells.
 
Cyparagon

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So the current would still be an amp. The linear driver just drops whatever voltage is extra and holds the current at 1A.

A switching driver on the other hand may result in less current draw.
 
LarryDFW

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Benm;

A much better solution would be an #18650 lith-ion cell.

The capacity is ~ 4 times higher than the 600 mah I have gotten with the 16340 Trustfires.

They can handle a 1 amp draw for over 2 hours.

LarryDFW
 
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