Smelly Oily Li-Ions

erco · 2013-02-21 08:49

Just received four AA-sized 14500 cells from Ebay China and two of them are oozing smelly oil. That's gotta be a bad thing. I wiped them down thoroughly and yet the oil returned, so I'll toss without even trying to use them. I've ordered dozens of Li-Ion cells from China and this is the first leakage I've seen. The smell is very pungent, so if you have a leak, you'll know it quickly.

For shipping, they were unusually well-packed in thick bubble wrap, so they didn't get damaged in transit. Curiously, each cell was individually wrapped in a poly bag. Maybe the seller knew some cells leaked...

mindrobots · 2013-02-21 08:53

Did you call HazMat before your neighbors find out??

Mark_T · 2013-02-21 11:15

For LiPoly (as opposed to LiIon) I've seen the following procedure for disposal recommended:

Dissolve some salt in cold water and place in a container outside, leave the cells for several weeks - the idea is the conductive water discharges the cells completely and
the water slowly infiltrates the cells and the lithium goes into aqueous solution. I've seen this recommended specifically for bulging cells which are by definition
in a dangerous state.

However LiIon is more sealed so I suspect some other procedure is appropriate. Putting in a sand-filled fire bucket outdoors is perhaps a paranoidly
safe option in the absence of other data.

pmrobert · 2013-02-21 13:11

Perhaps they're parting out the old 787 batteries? :-)

jazzed · 2013-02-21 14:08

Smelly Lions always accuse other Lions of the smell.

erco · 2013-02-21 14:15

Smeller's the feller!

NWCCTV · 2013-02-21 19:11

You guys have too much time on your hands!!! Any how, a couple years ago when Glen Beck was still on Fox News, he did a segment on the 700 plus page document that the government put out on how to properly clean up the new twisty style flourescent lights. It was actually quite hilarious as they were in downtown NY City with a hazmat suit and a broken light bulb on the sidewalk, along with trying to read the manual while donning the hazmat suit!!! I will try to find video of it and post it.

Humanoido · 2013-02-23 01:39

If the batteries were shipped in a non pressurized cargo bay at 30 to 40 thousand feet, there is a chance the battery containment was compromised. If that didn't happen, then batteries were shipped defective which is a practice used by not so scrupulous dealers in china.

erco · 2013-02-23 09:13

The Ebay seller fully refunded after I sent him these photos of discolored battery tops and oozing oil. (And promises to inform his supplier. Yeah, right!)

The funny thing was, only after I looked at the photos did I notice that these are bogus labels on the batteries. They aren't UltraFire batteries. The label reads UitraFlrc

BTW, seller is mxqtech/banggood, so avoid ! http://www.ebay.com/itm/400387180338

LoopyByteloose · 2013-02-23 09:46

I guess protecting their Ebay rating works out like it should.

Is that rust that I see? I could understand a pressure release in transit making them oiling, but rusty?

Bogus labels? Avoid like the plague. I have some 2N3055s with the Motorola label faked with a generic M and 90% out. It seems some jurisdictions consider these to be a unique brand and not subject to copyright infrigement, just another brand. But you are always getting junk. They won't hold up if they will work at all.

erco · 2013-02-23 11:39

That smelly electrolyte is corrosive. Just ask Boeing!

NWCCTV · 2013-03-05 20:19

@erco, these are not the same as the ones in this thread http://forums.parallax.com/showthread.php/145503-1.50-Li-Ion-18650-Batteries?highlight=battery are they? My 10 just arrived yesterday and they are fine. The holders arrived over the wekend and now I just need my chargers to show up!!!!

Also, I have a quetion about the batteries. About how long can I expect my BS2 Boe Bot to run with the two servos and maybe a ping and ir sensor operating? I do not need an exact figure, I just want to get a general idea.

erco · 2013-03-05 21:07

Different seller. Are you talking about the big 18650s or AA-sized 14500? You only want 2 of either, as they are ~4 volts each fully charged. That's pushing it for servos, you may want to add 2 silicon diodes to drop the voltage a bit. I didn't do runtime tests, but the 18650s will obviously last much longer than the 14500s.

LoopyByteloose · 2013-03-05 21:50

Regardless of being 14500s or 18650s, you will want some sort of low voltage cutoff scheme to protect the cells from damage of over-discharge.

You might use an ADC with a zener reference voltage on the microcontroller to do an orderly shutdown.

Duane Degn · 2013-03-06 07:12

erco wrote: »

You only want 2 of either, as they are ~4 volts each fully charged.

In an attempt to give my Popsicle stick robot a bit of extra oomph, I tried using a two cell LiPo to power it. I think it was less than two seconds later when one of the servos started smoking. I'd be very wary about using two 3.7V (which can be over 4.2V when fully charged) Li batteries with a servo. I know some servos state they can be safely powered with a two cell LiPo but I think those are the exception I believe the normal limit is around 6V.

These switching regulators have been working great for me. Besides dropping the voltage to a safe level for servos it also gives the servos a consistent voltage so they behave predictably (good for robot figure eights).

I've been trying to measure the capacity of one of the cells (18650) NWCCTV just linked to. I first charged it with the cheap ebay charger and a few days later hooked it up to my (HeliMax? (a nice one)) charger and put it in discharge mode. I initially set the cutoff to 3.5V. At 3.5V cutoff it stopped discharging after 17 seconds with a capacity of 10mAh.

After this first discharge, I charged it with my high end charger at 2.0A. The charge cycle was longer than the discharge cycle but not by much. The batter charged for 1 minute 19 seconds with a capacity of 6mAh.

I think the automatic cutoff chip must have been activated because I think the battery is starting to show signs of behaving.

I changed the discharge cutoff to 3.0V and discharged the battery again. This time the battery discharged time was 12:34 (minutes:seconds) with a capacity of 481. What gives me hope about these batteries is the initial voltage for the just mentioned discharge was about 3.5V. The voltage at the end of the discharge was about 3.8V.

I'm hoping the automatic cutoff chip has reset. Currently the battery is charging again and it has been going for over 15 minutes. I'm hoping I can figure out a reliable way to reset the cutoff chip whenever it trips. I'd also like a reliable way of detecting when the cutoff chip activates.

I just checked the charger, it has been charging the battery for 27 minutes and it has delivered 306mAh of power to the battery. I don't think I'll have a good indication of the battery's capacity until I perform another discharge since the protection chip may have previously keep the battery from full discharging.

I'll edit this post when I complete the current charge/discharge cycle.

erco · 2013-03-06 10:05

Duane, you're one tough customer, demanding more capacity than 10-16 mAh.

All I have are the cheap eBay Li-Ion chargers like http://www.ebay.com/itm/New-Universal-Battery-Charger-AA-AAA-18650-16340-CR123A-Smart-Charger-Hot-EA-/360604411155?pt=Battery_Chargers&hash=item53f5b2a513 They just have a red & green LED, it's not clear if they are "done" charging when the LED turns green, or if the charger has changed modes (CC to CV?) and they still need to trickle up for a while.

I'll be curious to find out how much extra capacity you get using your expensive charger. Wouldn't it be funny if the cheapie was as good as or superior...!

Edit: See http://en.wikipedia.org/wiki/Li-ion and read "History". I think it's funny that one of the developers of Li-Ion technology was named John "Goodenough". With that name, why would anyone strive for excellence?

Smelly Oily Li-Ions

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