Fake (refurbished) Li-ion batteries - how dangerous are they? - Page 1
Forum section: electronics / general

author: mianchen
author_rank: Regular Contributor
timestamp: December 22, 2012, 03:06:58 pm
content: I bought a couple of 18650 batteries from China as ' order filler' for a big order of some Arduino shields and stuff. They were advertised as new 4900mAH UltraFire Li-ion and over 500 of them have been sold. I didn't believe the 4900mAH bit for a second, but just want to see how close they can get.The order turned up 10 days later (pretty fast), everything else (shields etc) worked fine. But these batteries look so fake!You can see the typos:Sheif-lief around 10 yearsEnvirommental friendlyI'm charging one of them at the moment in a metal container (in case it explode or catch fire). I'm gonna test them once fully charged and report back. If you think it's too dangerous please let me knowPS. Contacted the seller, refunded immediately no question asked... hm...fishy...

author: mianchen
author_rank: Regular Contributor
timestamp: December 22, 2012, 03:35:50 pm
content: hm....1.5A discharge only lasted 25mins, 4900mAH my a***, what a POS, not gonna waste my time trying to use them...

author: Skimask
author_rank: Super Contributor
timestamp: December 22, 2012, 03:40:26 pm
content: Try discharging at C/10 and see what happens...

author: SeanB
author_rank: Super Contributor
timestamp: December 22, 2012, 03:51:04 pm
content: Charge to destruction time then, with video............

author: tom66
author_rank: Super Contributor
timestamp: December 22, 2012, 03:58:08 pm
content: I'll just leave this here:http://lygte-info.dk/review/batteries2012/UltraFire%20BRC18650%203000mAh%20(Red-silver)%20UK.htmlAnd this "teardown":http://www.rzbiker.com/20120527_184518.jpg

author: Skimask
author_rank: Super Contributor
timestamp: December 22, 2012, 04:40:36 pm
content: Quote from: SeanB on December 22, 2012, 03:51:04 pmIs there a "Like" button around here?

author: Tube_Dude
author_rank: Regular Contributor
timestamp: December 22, 2012, 05:25:23 pm
content: Quote from: Skimask on December 22, 2012, 04:40:36 pmYes!

author: JoannaK
author_rank: Frequent Contributor
timestamp: December 22, 2012, 05:45:56 pm
content: Quote from: Tube_Dude on December 22, 2012, 05:25:23 pmI think that ++ or +1 would be suitable for this site..One good thing about those cheap fake batteries is, that there's verly little anything in them. So with all likelyhood they make smaller mess than full size battery if they blow up.

author: Electr0nicus
author_rank: Regular Contributor
timestamp: December 23, 2012, 01:13:54 am
content: They are called "Ultra Fire" for a reason!Because they set your house on fire if you charge/discharge them unattended.

author: Razor512
author_rank: Regular Contributor
timestamp: December 23, 2012, 02:20:12 am
content: china li-ion batteries never give you the rated capacities, eg I have a few china NB-5L batteries. The real canon is 1120 mAh, and the china one is listed at 1450mAhthe china one has about a quarter of the battery life of the real canon battery, but that is good enough to get a good bunch of shots.They also weigh about half as much as the canon battery and they only take up about half of the space as the battery pack (you can see through the outer casing if you shine a light through.I have been using the batteries regularly for the past 2 months and they still work. (The battery was sold as a 2 pack for $4 and free shipping) If I were to buy enough of these to equal the price of the canon battery, I would have 18 of these batteries which will offer the capacity of 4.625 canon batteries.

author: LaurenceW
author_rank: Frequent Contributor
timestamp: December 23, 2012, 04:28:59 pm
content: This is an interesting thread that perhaps deserves more views (unless this material is covered elsewhere?)I too have bought some "no-name" Li-Ion batteries (actually branded "Ultracell" - huh?) off FleaBay, and rated at 4200mAhr. I have done some carefully controlled charges and discharges of these cells, and get no more than 2400mAhr out of them. On wider reading, it would appear that such high capacities for 18560-format cells are just not yet really "out there"Some cells apparently include built in "protection" and some others rely instead on small protection PCBs in the battery holders themselves (although I am not really convinced this makes any them damage-proof).One lesson - the same basic 18650 size battery and holder vary in actual size a good deal! Not all 18650 batteries fit all 18650 holders - be warned.Another lesson - ya get what ya pay forDid I really need to learn that? Again?

author: JoannaK
author_rank: Frequent Contributor
timestamp: December 23, 2012, 05:10:36 pm
content: Quote from: LaurenceW on December 23, 2012, 04:28:59 pmYep. there's a link to that .dk site above, where site owner (forgot the nick alllready but he posts here) has measured the lenght/width of the batteries.. and there's a lot variance on those. Alongside the capacity.QuoteYep. Usually that tends to be true. Occasionally one may find something good with nice discount on sites like E,-bay, but more often it is just that so typical low-grade junk.I understand that minor 'boosting' the stats is more or less the norm, but claiming over 2* capacity is downright fraud. => Bad reputation to all sellers of similar products.

author: Electr0nicus
author_rank: Regular Contributor
timestamp: December 27, 2012, 01:45:42 pm
content: That's how I like my battery cells: made in CanadaActually the battery pack was spot on 2800mAh, what should be, because I use a 4s2p arrangement of 1400mAh cells. Unfortunately I over- discharged them a little bit, so they now only have 2400mAh left.Ah well, shit happens.

author: Monkeh
author_rank: Super Contributor
timestamp: December 27, 2012, 03:31:48 pm
content: Those look familiar. I just manually charged a 6-cell laptop pack full of those (well, 2000mAh versions), only to find the pack controller is dead so it won't work anyway.Two of them had gone negative, they still took a good charge.

author: amyk
author_rank: Super Contributor
timestamp: December 28, 2012, 11:33:33 am
content: Those areMolis... not as popular for some reason, probably high cost/capacity. But the 1400mAh ones are designed for high discharge currents, up to 20A according to the datahseet.

author: Electr0nicus
author_rank: Regular Contributor
timestamp: December 28, 2012, 11:32:20 pm
content: Quote from: amyk on December 28, 2012, 11:33:33 amI don't know myself, why they aren't as popular as other manufacturers cells. I only used them for my battery pack by accident, because my local electronics store had them. They aren't as dirt cheap as those Chinese batteries, but as you can see on tom66's linked in images above, you get what you're pay for. Those Molicells costed 4€ each which is approx. 5.3USD. That's a reasonable price for a quality cell.

author: baoshi
author_rank: Regular Contributor
timestamp: December 28, 2012, 11:53:58 pm
content: You should trust your feeling at first thought. So far largest capacity for 18650 is 3400mah, a Panasonic model NCR18650B