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Best value ($ per mAh) on 18650 cells?

rhd

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I think Larry's onto something there. Ask someone in the IT helpdesk field if they have any old battery packs you can have. At the very least, you'll end up with a handfull of cells that, while used, have all been used at about the same rate and amount. To them, it's trash because the computer won't use it. Usually that means they are at maybe 70-80% of their original capacity at the currents that the computer would be drawing from them. To us, it's more than capable of loading a single diode and its supporting components, and I'd imagine your use would be just as "light" a load on the cells as our lasers and such.

Not to mention the tabs are already welded into usually 3s2p configuration, meaning fewer connections for you to make.
That's a really good idea. I'll just need to find an IT help desk.

I wonder if it would be evil to just figure out which stores do laptop battery pack recycling, and see about grabbing some of those? In some cases, they just have giant cardboard drop boxes at the front of the store. I could ask permission. But either way, I'm sure that the way I would be recycling these cells is at least as, if not more, environmentally friendly.
 



LarryDFW

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There are a number of ~2000mAh to 2500mAh options, on various sites and eBay, for around $2.50 to $3.00. The challenge, is that the value disappears if they're really 600mAh. But the value would still be there if a 2500mAh is really 1800mAh, because even at that level, for under $3, it's a good mAh per $ ratio.
Here's another better value option @ $1/1000mah to meet your parameters:



Sanyo Prismatic Cell - $2 for 2000mah from Dell factory packs

I have plenty of these (and they're U.L. tested).

They are also available in some laptop batteries if you can find them.

LarryDFW

P.S. Also have lots of used LG 18650 cells - 2600mah for $2.50 ea.
I like good value in a cell also.
 
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rhd

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Oh, now some of that is really intriguing. I need to read up a bit this evening on prismatic cells.
 

ryansoh3

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P.S. Also have lots of used LG 18650 cells - 2600mah for $2.50 ea.
I like good value in a cell also.
Larry, you don't ship internationally, do you?

I would love to grab a pack of those used LG cells!

Cheers!
 

LarryDFW

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rhd;

Please take precautions with those Ultrafire cells.

There are absolutely NO commercial 3800mah cells.

A company that spouts untrue statements generally, cannot be trusted.

A friend of mine recently had an Ultrafire cell vent while he was holding a small flashlight in his mouth.

Luckily, he threw it down before it blew the switch cap off the light.

That is precisely why I insist on U.L. testing with "brand name" cells.

LarryDFW
 
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LarryDFW

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Flaminpyro;

Here is an enlightening review by a flashlight enthusiast on the 3000mah Ultrafire cell:

http://www.amazon.com/review/RJFGB6VNWNHT8/ref=cm_cr_pr_viewpnt#RJFGB6VNWNHT8

Notice the extremely poor performance after the "new" cell after a period of time.

The Panasonic 3100 cell had ~400% of the performance after some time elapsed
(although elapsed times were different, my 3100 Pany cells retain >95% capacity after 2 weeks).

Discharge upon short term storage is indicative of poor construction technique.

LarryDFW
 
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ryansoh3

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A friend of mine recently had an Ultrafire cell vent while he was holding a small flashlight in his mouth.

Luckily, he threw it down before it blew the switch cap off the light.
Wow, that was very close. But holding a 18650 light in your mouth? :thinking:

Larry, I was wondering if you shipped cells internationally. I'd be interested in your used LG cells.

Cheers!
 

LarryDFW

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Larry, you don't ship internationally, do you?

I would love to grab a pack of those used LG cells!

Cheers!
USPS has recently refused to ship lithium ion cells internationally due to the use of passenger aircraft.

This only leaves UPS & DHL as expensive shipping options.

Since you are IN Korea, I would look for used cells right there in your country.

I am still looking for a good method of transport into Canada (customs and shipping costs).

LarryDFW
 
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ryansoh3

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USPS has recently refused to ship lithium ion cells internationally due to the use of passenger aircraft.

This only leaves UPS & DHL as expensive shipping options.

Since you are IN Korea, I would look for used cells right there in your country.

I am still looking for a good method of transport into Canada (customs and shipping costs).

LarryDFW
Gotcha.

While I do live in Korea, LED flashlights and Li-Ion are not as popular as it is in the West. Cells are ridiculously expensive--$10 for a fake Ultrafire 3000mAh cell :wtf:

Where do you find used (but good) 18650s? In laptop batteries?

Cheers! :beer:
 
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LarryDFW

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Used laptops are a source . . .

but not all the cells are brand name.

Some may be damaged by continuous charging abuse.

LarryDFW
 
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LarryDFW

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Wow, that was very close. But holding a 18650 light in your mouth? :thinking:

Cheers!
He is a hunter.

He and his friends constantly hold their lights in their mouth,
to free up their hands.

Need some compatible headbands.

LarryDFW
 




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