Sketchy eBay batteries...

[SKeeZ]

Not sure why i decided this was a good idea but hell, if these turn out to be ligitimate (highly unlikely) it might even be worth it. So heres the story. I built My 2W C6 laser and i don't have batteries for it. So, i went on eBay and found some "ultrafire" (definitley not ultrafire) 5ooomAH - lol 18650s. they cost me $10 with a charger. I expect for these to arrive before the 24th here is the link to the product page: 4pcs Ultra Fire 18650 3.7V 5000mAH Lithium Rechargeable Battery +18650 Battery Charger

 

[ryansoh3]

It's best to avoid these cells at all cost.

Not only do they have very very low capacity (<2000mAh), they can also be very dangerous. Most are laptop pack recycles, tired and old.

It's truly worth it to get some good cells like the Sanyo 2600mAh, Panny 3100/3400, as well as LG or Samsung ones.

Check out HKJ's battery reviews and tests: http://www.lygte-info.dk/info/indexBatteriesAndChargers UK.html

 

[Livinloud]

Yeah, Ryan hit the nail on the head and crushed it. You know how easy it is to take a dumpy old laptop battery and rewrap it.....TA DA NEW!

 

[SKeeZ]

Thanks guys, not sure why i wasted 11 bucks on those. Will the charger work at least?

 

[ryansoh3]

The charger should work, but safety is once again an issue.

They might overcharge your batteries over 4.20V and in worst case scenarios might catch on fire.

Hope you don't charge your cells unattended with this one.

 

[djQUAN]

Based on experience with the free "included" charger that comes along with lights or lasers.... no. Cheap chargers don't put out the correct voltage but you can check it with a multimeter if yours somehow puts out the right voltage. The cheapest chargers I'd use are the Nitecores.

 

[SKeeZ]

So heres whats up. I have a balance charger from my RC days and I purchased some ultrafire 1000mah 16340s. I think this is a better option.

 

[Blaster]

I think the real issue is the safety of the batteries if they only output half the rated current or less not an issue, issue is i have had a few get very warm and start to leak even with a good charger and then i get rid of them quick most of my batteries are now Panasonic, sanyos or Sony's i still have some ultrafire, missfire batteries that do work fine at less than half the rated current.The most important thing i believe is a good charger with seperate channels and sensing for each battery, voltage,current and temperature ..to lessen the issue of a disaster of a battery exploding which lithium ions do from time to time, not much but they do

 

[SKeeZ]

Since these are 1000mah rated ill charge them at .5A for safety in a LiPo fire bag. This eliminates danger. My charger can also detect a number of issues, heat, short, etc. My charger also dynzmically adjust charge voltage and current.

 

[ryansoh3]

Unfortunately the 16340 cells are not 1000mAh at all, probably closer to 600mAh, so try using a smaller charge current, such as 300mA.

 

[Blaster]

Yes i have 16340 GTL brand? I got a heap like 24 at 80 cents each and are supposed to be 2000ma yeah right from the tests i have done they are about 750ma and don't give me any grief, charge well don't get hot last about 35 minutes in a 280 mw red @ 340ma before start to get a bit dull, its the luck of the draw, but i will say those 16340s i have were brand new not old notebook retreads so that must make a difference and at 80 cents each in bulk cant go wrong, i obviously use the same intellecharger to charge them and they are fine none have kicked the bucket in the 12 months or more i have had them.

 

[LarryDFW]

Unfortunately the 16340 cells are not 1000mAh at all, probably closer to 600mAh, so try using a smaller charge current, such as 300mA.

This is the reason enthusiasts should buy quality #18650 cells.

Panasonic has actual 3400mah cells in #18650 size.

Much greater capacity, lower internal resistance and UL 1642 safety testing . . .

gives you higher current, and longer run times.

(and shorter charge times)

Larry

 

[BShanahan14rulz]

I've never had cells get even noticeably warmer than the air around it... I'd drop the charge current or toss those cells. Not a big fan of small lithium cells anyways

 

[SKeeZ]

Currently charging some crappy old laptop salvaged 18650's. Here's a picture of the charger data.

Here is a picture of the battery outside of the bag.

Now, some may think i'm crazy but i am going to try to but this in my C6 laser and make it work. here is a picture of the o-so-unfamiliar host.

And here is a beam shot of it with proper batteries.

I will try to get the same beam shot (if it works) with the old 18650.

 

[Things]

Thread title reminds me of this:

 

[SKeeZ]

Capacity seems to be pretty good at least 2000mAh (at this point in the charge) possibly even 2500mAh or more. I know that because the voltage of the battery right now is 3.9V (3.6 at the begining of the charge) @ 1.5Ah of charge.