Anyone had problems with Ultrafire lithiums?

I bought a pair of Protected Ultrafire 2400mah 18650 and a pair of Protected Ultrafire 3.6V 880mah 16340 from DX a few months ago... i tried both 18650's when i got them before charging and 1 seemed dead and didnt make any light from my flashlight...So i charged them both and they seemed to work fine. But then on my 1st full use of 1 of them(i'm not sure which one) i was expecting the protection circuit to kick in when my light got dimmer and dimmer but nothing happened so i checked the voltage of the battery and it was reading 2.8V so i decided not to use it any further as i've heard running lithiums below 3V could damage them.

Anyone know if that is true or if the cut off voltage is meant to be lower?

I've been using my 16340's fine but i recently tried using the pair, which i charged a few weeks ago, in a new flashlight but it wouldnt light it up so i thought there was somthing wrong with the connection in the flashlight but i tried a 18650 in it and it worked fine. I checked the voltage of the 2 16340 cells and 1 was fine at 4V but the other seemed to be unreadable giving me really low voltage that kept on changing...

So should i try charging it again? or would it be best to get new batteries?

Anyone else had these problems with ultrafire cells or even other brands?

We've had a lot of trouble with them lately. Out of six we bought, three had problems. A protected 18650 can click off the protection circuit if it goes too low, and shows nearly zero volts. It's worth a try to stick it back on the charger. If it's ok it'll click back on pretty quick. I charged one dead cell for less than a minute and got it back to 3.7v. It was ok from then on. One was doa and two went dead after just one charge and couldn't be recharged. :mecry:I've bought just as many AWs over the same period of time and all the lights that had problems with ultrafires now run just fine on AWs. Worth the extra buck or two imo.


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ah k thx...you wouldnt happen to know what voltage the protection circuits meant to kick in would you? yeah i know the AW cells are meant to be the best you can get but they also seem to cost more than twice the price. i bought some unbranded protected 16340's a few years ago and theyre still running great but i've heard that you shouldnt use them for more than a few years so i might get some AW's if i get any more trouble from the batteries

Apparently TrustFires are more reliable than UltraFires.

Regardless, getting a dud or two is a known problem with cheap cells. This is why I think you should always order two more than you need. Places like DX will replace DOA cells, but it takes a month for the package to get to you; if you have spare cells you can use those instead, and use the replacements on something else when they arrive.

AWs are supposedly the best you can get, but they sure make you pay for it. I've always preferred to get twice the number of cheap cells; even accounting for the occasional dud and often exaggerated ratings you still end up with rather more capacity for your money.

I got those 18650 too. They have 1400mAh instead of 2400. I also read over 200mOhm internal resistance. They perform really bad, but i put them in my low power lights.
Give those a try:
http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=2761
cheaper and work much better. These are really 2200mAh cells but thats still much more than you get from the ultrafires.

http://www.dealextreme.com/details.dx/sku.5776

I have those, they tested over 2400mAh at 1A. I'll recheck them, when they have a bit more discharge/charge cycles on them

Raymond said:

http://www.dealextreme.com/details.dx/sku.5776

I have those, they tested over 2400mAh at 1A. I'll recheck them, when they have a bit more discharge/charge cycles on them

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I just re-celled a WinCE subnotebook using the very same cells. They seem to be doing OK so far.

I was totally satisfied with 4 of mine Ultrafire 18650/2400mAh connected together 2s2p to get 7.4V/4800mAh, until one night protection kick in and from that point nothing was the same.

That night when I got back home from my bike ride I check voltage and the battery pack has 5.4V oo:oo:oo:oo:

I charge the pack and the voltage was back on 8.3V and I was really surprised how good this protection is until next night ride. O man was I surprised when light went off again,...

Voltage was again 5.4V on the pack and I immediately know that one cell is out of order.

I took the pack apart and find that one pair of cells has only 1.7V,... jap one cell show 0V. When I remove protection circuit the cell itself measure 3.8V so the protection doesn't work correctly.

Is there anything I can do to fix that problem or just throw it away and buy some good Li-Ions.

Thank you,
Iztok

Remove the protection and use the cells unprotected. If there is risk of overdischarging add a small volt meter (like this one, or one of those small cheap multimeters) so you can know the charge level at any time and switch off the light when the voltage gets too low.

Hmm, I was planning on ordering 6x 18650 cells for a torch I'm making, I imagine I'd probably get a dead one in the mix.. maybe it's not worth it? Are there any other options that are only slightly more expensive?

the trustfire protected 2400mAh 18650s seem to be fine cells, although admittedly, I don't have a lot of data to support that claim. Mine are working fine, as are about 10 others that I've read about on the forums. Maybe more importantly, I haven't found any reports of them failing. Also, there are a few tests of the capacity of these cells and they seem to surpass their claimed 2400mAh.

They're less than half the price of AW cells, so you can buy 8 instead of 6 and still come out way ahead, even if one or two are duds.

Buy them from DX, their support system seems to be better than KD's.

I purchased two 18650, two 17670, and four 123 Ultrafire cells from DX, and currently only one 18650 and two 17670 cells work. The 18650 cell was charged once and left in a flashlight fully charged but died about a month later without seeing any use. All of the others died after less than 4 charging cycles. In comparison, I have about twelve AW cells (all sizes from 123 to 18650) and two Battery Station cells (123) that still work after 20+ cycles and ALL are still going strong. The Ultrafires looked well made, but after these failures I'm going to stick with AW or BS cells.

9x23

VanIsleDSM said:

Hmm, I was planning on ordering 6x 18650 cells for a torch I'm making, I imagine I'd probably get a dead one in the mix.. maybe it's not worth it? Are there any other options that are only slightly more expensive?

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Order Trustfires, not Ultrafires, and order one or two more just to be sure. There are always uses for surplus cells if they turn out to all be OK.

9x23 said:

I purchased two 18650, two 17670, and four 123 Ultrafire cells from DX, and currently only one 18650 and two 17670 cells work.

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Ultrafires are apparently of worse quality than Trustfires. I re-celled the battery pack for a handheld PC with two Ultrafires; it works, but I'm not getting the runtime I should. I think I'll open it up again and re-recell it with Trustfires instead.
The Trustfire 14500 I'm using in my NDI has seen a good few cycles and it's still going strong.

Can anybody tell me the difference between these 3 batteries?

http://www.dealextreme.com/details.dx/sku.5790 $10 2500mAh blue protected trustfire

http://www.dealextreme.com/details.dx/sku.6979 $9 2500mAh blue protected trustfire

http://www.dealextreme.com/details.dx/sku.5776 $10.49 2400mAh grey protected trustfire

I suppose I'll go with some trustfires.. but I don't know which ones to pick?

The grey ones get the best reports.

i have 8 ultrafire 16340 4 gave up working low volt protection kick and it will not turn off, also use trustfire 18650 with no problems it seems the way to go is with the trustfire over ultrafire

Thanks Ray,

Anybody else have some experience and/or opinion of which battery is best?.. what's the difference between the 2 blue ones?

Fallingwater said:

Apparently TrustFires are more reliable than UltraFires.

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They are both unreliable and inconsistent. This forum is littered with reports of people being let down by them.

Fallingwater said:

Ultrafires are apparently of worse quality than Trustfires.

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It's hard to imagine anything much worse.

VanIsleDSM said:

I suppose I'll go with some trustfires.. but I don't know which ones to pick?

Click to expand...

Neither, if you don't want to waste your money. Buy AW Li-Ion cells instead.

DM51 said:

They are both unreliable and inconsistent. This forum is littered with reports of people being let down by them.

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Cue the usual "buy lots of product and you'll always find defective samples" argument.

It's hard to imagine anything much worse.

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So how about the various tests people have made that show Trustfire 18650s consistently outperforming AWs?
I'm not saying Trustfires are better - there are issues of internal resistance over time that need to be considered, and I haven't seen that tested yet - but they certainly aren't bad, and they have a very good price/performance ratio.

Ultrafires, on the other hand, I'm not too sure of.

Neither, if you don't want to waste your money. Buy AW Li-Ion cells instead.

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I don't doubt AWs are great cells, but most people will be happier with a higher price/performance ratio, just as many people are perfectly happy buying Swatches instead of Rolexes.

VanIsleDSM said:

Anybody else have some experience and/or opinion of which battery is best?.. what's the difference between the 2 blue ones?

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The blue ones seem identical to me. There have been good reports on the grey ones, so I'd say get those. 100mah more or less isn't worth worrying about, it's such a small amount of charge for such a large cell that it'll get lost in the noise.

Ok, I think I'm gonna go with the grey cells then...

Those AW cells are ridiculous oo: more than twice the price plus shipping.. and specs aren't as good, no thanks.. As stated earlier it would make much more sense to buy twice as many trustfires for that price.