Need help choosing unprotected 18650 for Convoy S5

[Chloe]

@*the*

First of all, I think you are fully qualified to use Li-ions. Remember to respect them, but don’t be too afraid.

I remember reading all these disastery threads before I joined BLF and they can put you off especially as I didn’t really know. Even now after rereading them, I am wondering if I should really leave a cell inside a light I use often. “What if it vents?” “Will the light explode?”

[Helios1 (Helios-)]

Yea, there is always a small risk but the chances should be low for you at least. Your looking for good cells & you won’t abuse them.

You can start out (or stick with) Li-Mn / IMR.
Did you go for those AW IMR 2000mAh 18650s? Any li-ions on the way?

[Chloe]

I didn’t get any AW yet. I thought they were out of stock but I noticed two AW 2000mAh is 26 USD shipped, compared to 14.79 USD for a pair of Panasonic 3400mAh.

Also, 2000mAh doesn’t sound too low but I was also planning on using the ML-102 with a cell to top up my phone. I’m not really sure how much it needs to be.

[Dimbo_The_Blinky]

@Chloe

I found the story I read on CPF:

Vapors aren’t the real problem in a chemical factory (being more of a “normal course of business” kind of deal), but that’s darned interesting.

It’s amazing what you can observe, just by looking!

Not tending to trust blogs and chatroom posts (present company EXcluded, of course!), I went and found something only mildly interesting if directly relevant:

GCMS Analysis of Gas Generated from Lithium Ion Rechargeable Battery Cells

You’ll notice there’s no HF, and there are those unlabelled peaks… Not sure what to make of this, especially with his 80C temperature limit, but it is directly relevant.

But let’s look at the CPF story itself. When I was maybe 10, we found a discarded gallon bottle of H2SO4. Yes, I sniffed it. Do NOT try this at home!! But, it seems to have somehow enhanced my sense of smell. All ends well in Dimbo’s weird world! So this story pushes a couple of my buttons. But wait…

HF, sniffed or even touched, is exactly as bad as the writer implies!!! His claim of “last night” isn’t plausible, given the rest of the story, but a cautionary tale isn’t told in court. So don’t let me diminish his advice. Think! Pay Attention! Be Very Careful With Chemicals! Even DiHydrogen Monoxide will kill you quicker than keep you alive!

But WAIT…

For DECADES now, in “the land of the Free, the home of the Brave”, “we the People” have allowed anonymous agents of our government to add Flouride to our water supply. You can say that softer, less scary, but it’s no less a fact.

If you track down the HF lead, guess what the MSDS says? No, really you must guess or I will pout!!

Keep your sense of humor…

Here’s some Truth, to still Laughter in you forever:

Hydrofluoric Acid Chemical Safety Information

If you’re not going to read the whole thing, before you drink public water again, at least read the last page:

Fluoride from any source has the same toxicity. A mass poisoning occurred at a state hospital many years ago when a bug poison containing NaF was mistaken for powdered milk and added to scrambled
eggs. There were reported to be 47 deaths. In some regions of the country the levels of fluoride in the
water are too high and this causes mottling of the teeth and loss of calcium from the bones.
Inhalation of HF produces an immediate injury to
the lining of the lungs with hemorrhage pulmonary
edema and death. It may take only about 5 minutes of
exposure to inhaled HF to produce death in a
couple of hours.
All in all, fluoride from whatever source can be very dangerous.

Ask your nearest bureaucrat, how do they put Sodium Fluoride (NaF) in the water they make you pay to drink? They’ll bury you in BS, but you can beat them back with the Material Safety Data Sheet for Sodium Fluoride . Especially this section:

Special Remarks on other Toxic Effects on Humans:
Acute Potential Health Effects: Skin: Causes skin irritation and possible burns, especially if skin is wet or moist. Eyes: Causes eye irritation and burns. May cause chemical conjunctivitis and corneal damage. Ingestion: Harmful if swallowed. Causes digestive (gastrointestinal) tract irritation and burns. May cause severe and permanent damage to the digestive. Ingestion of large amounts may cause salivation, thirst, nausea, vomiting, hypermotility, diarrhea, and abdominal pain. May affect behavior/central nervous system/nervous system (headache, nervousness, dizziness, seizures, convulsions, tremor, muscle weakness, somnolence), respiration (respiratory depression, dyspnea), cardiovascular system (weak pulse, hypotension, dysrhythmias, cardiac arrest), liver, urinary system (polyuria, polydypsia) brain, metabolism (loss of appetite, hypcalcemia, hyperkalemia, hypomagnesia, ), teeth, bones, and blood (changes in red and white blood cell count, interference in blood coagulation) Inhalation: Causes irritation and chemical burns of the respiratory tract with coughing, breathing difficulty and possibly nasal
septum perforation and coma. May affect bones. Chronic Potential Heath Effects: Chronic ingestion may cause fluorosis. Effects of fluorisis may include joint pain, weakness, limited joint mobility, brittle bones, ossifications on x-ray, thickening of long bone cortices, calcificaiton of ligaments, osteomalacia, osteosclerosis (skeletal (bone and teeth) abnormalties) and mottled tooth enamel. Other symptoms may include anemia, nausea, vomiting, diarrhea or constipation, kidney damage and weight loss/anorexia. Chronic inhalation may cause bronchitis to develop with cough, phlegm, and/or shortness of breath, liver (hepatic enzymes increased, jaundice)

…

Yeah. You’re right. This doesn’t have a dad-gum thing to do with outgassing or any other Safety issue of 18650s.

But it could help explain the True Believers’ discomfort with Facts, Logic and Truth… “May affect behavior”…

At least it should bring some perspective to the CPF story…

Speaking WITH you all, of course, not ABOUT any of you!!!

Dim
(And no, I haven’t ginned up a dead-short test rig yet! All this put a bee in my bonnet about finding a willing chemist with a GCMS to test the result.)

[Chloe]

That’s interesting! 80°C, you’d expect it to vent already!

I did find this, which might be biased? I don’t know what kind of Li-ion cells it refers to:

Furthermore, when the electrolyte is combined with water, there is the potential for hydrofluoric acid to form

But then this makes it sound like there needs to be a fire involved for it to be toxic:

One problem is that many lithium-ion batteries today contain fluorine, which readily combines with hydrogen to make hydrofluoric acid (HF). In accidental battery fires, HF is noxious, dangerous to the touch, and an inhalation danger.

PG/Duracell say in their MSDS:

Hazardous Combustion Products:
Thermal degradation may produce hazardous fumes of lithium and manganese;
hydrofluoric acid, oxides of carbon and sulfur and other toxic by-products.

But these are primary cells not rechargeables. :weary:

[Helios1 (Helios-)]

AW tends to charge a lot. You can get the same quality, often the same exact cell elsewhere for less.
Efest IMR 18650 2000mah outperforms AW IMR 2000mah on HKJ’s charts.
Panasonic CGR18650CH are kind of in between Li-mn / li-ion & are suppose to be good too… If the FT forum report of one venting hasn’t turned you off them. :face_with_monocle:

For li-ion I’d go for sanyo 2600mah over panasonic. The 3400mah sounds nice but it can’t keep its voltage up.
Scaru’s Li-ion Battery Safety and Shopping Guide with HKJ’s data.

[Chloe]

Ahh, thank you! I hadn’t settled on the Panasonics. I need to do more reading. >.<

Aww, these are temporarily sold out and apparently discontinued (can’t find anything directly from Panasonic about this though):
http://www.fasttech.com/products/0/10001980/1141101-panasonic-cgr18650ch-rechargeable-2250mah-3-7v

[Helios1 (Helios-)]

I believe all panasonic "CGR" cells use an in-between chemistry. Panasonic seems to use "NCR" for their li-ion cells.

Panasonic is definitely high quality cells but our leds will dim before we can get 3400mah out of their NCR18650B. Even for charging a cell phone, 5 volt usb boost converters get less efficient & provide less current to your phone as battery voltage drops.

Panasonic "3400mah" & Sanyo 2600mah. HKJ's charts.

[Chloe]

Ahh I see! Well, it seems convoluted to order Efest IMR (I have sent them an email for a quote), so I may get some Sanyo from FastTech.

[moderator007]

@Chloe

Ahh, thank you! I hadn’t settled on the Panasonics. I need to do more reading. >.<

Aww, these are temporarily sold out and apparently discontinued (can’t find anything directly from Panasonic about this though):
http://www.fasttech.com/products/0/10001980/1141101-panasonic-cgr18650ch-rechargeable-2250mah-3-7v

www.panabat.com/documents/cgr18650ch-data-sheet.pdf‎

[Dimbo_The_Blinky]

@Chloe

I did find this, which might be biased? I don’t know what kind of Li-ion cells it refers to:

Looks like I won’t be needing that rig after all. There’s the dead short test (“akin to dropping a wrench across the positive and negative terminals”), writ large! But really,

Smoke also exited the vent hole but a fire did not result

You really can be a buzzkill.

Seriously, Thanks for taking that off my plate!

But he starts with the “Don’t leave the battery in the charger once it is fully charged” method. Somewhere I found some recommendation that Life Cycle would be extended by holding them at “Full Charge” (whether that’s 3.9 or 4.2 — apparently 3.9v Full is another way of extending its Life)… I don’t want to start duelling with PDFs, but I’m working my way through Sony’s Lithium Ion Rechargeable Batteries Technical Handbook but it’s dense. I did find this:

The battery is charged at a constant current to 1CmA to a terminal voltage of 4.2 V under constant-voltage, constat-current [sic] conditions, and after the terminal voltage has reached 4.2V the battery is continuously charged for 28 days at constant voltage

where the UUT passed. That’s consistent with my limited experience with “giveaway” chargers. Jump to the Abuse Tests on p22… I might get an “Intrinsically Safe” rating after all, if this can be backed up empirically.

That’s all just Sony’s opinion, of course, but they seem to have developed some useful information. I’m still looking for ANY analysis of the outgassing in the case of overtemp/overvoltage. Your guy said

Avoid designing airtight battery compartments. In some cases, gases (oxygen, hydrogen) may be given off, and there is a danger of a battery bursting or rupturing if ignited by sparks.

, which is still not “user-friendly”.

3–2 Safety mechanisms
For example, cylindrical batteries are incorporated such safety mechanisms as circuit-breaker devices, safety vents, and PTC devices. The maximum charging voltage of the dedicated recharger for these batteries is set to 4.2 V, but should the recharger malfunction and the maximum setting become invalid, the Li2CO3 added to the cathode would dissociate from around 5 V, and the gas generated as a result would cause an increase in the internal battery pressure. This change in pressure would cause the safety vent to be deformed, removing the cathode lead and cutting off the charging current, thereby ensuring safety. In addition, should the battery be exposed to a fire or some other extreme temperature condition causing a sudden increase in internal pressure, the safety vent would split, averting possible danger.
Moreover, should erroneous use result in the flow of large currents and battery charging and discharging, the PTC device will act to reduce the current

They seem awfully confident, for not disclosing the reactions of the Li2CO3

…

Of course that’s just one source, but you mentioned you’re tired. I figured this would knock you right out.

Now I’m going to take the easy route & put on my Indiana Jones hat & try to go dig up where the horror stories come from (Actually I think you hit it already: Lithium is not Lithium-Ion!)…

Evermore Dim

[Chloe]

@Dimbo The Blinky

Seriously, Thanks for taking that off my plate!

I don’t understand! :~ Did you want to do these tests?

@Dimbo The Blinky

Of course that’s just one source, but you mentioned you’re tired. I figured this would knock you right out.

These look good, no? Nice and shiny… I hope they reply soon! :bigsmile:

[Helios1 (Helios-)]

It can be annoying to get efest batteries. E-cig sites carry them. Myself & others have done FT product requests.
I don’t normally like getting batteries from ebay but I went for efest imr 10440 from Saftymind (100%, 4,761 reviews)… No efest imr 18650 2000mah listed from saftymind though. :~

[Helios1 (Helios-)]

@Dimbo The Blinky

Now I’m going to take the easy route & put on my Indiana Jones hat & try to go dig up where the horror stories come from (Actually I think you hit it already: Lithium is not Lithium-Ion!)…

Careful Indie, the locals say there be some nasty snakes around.

[Dimbo_The_Blinky]

@Chloe

I don’t understand! :~ Did you want to do these tests?

Nooooo. I wanted to blow up a battery!! But Mythbusters-style, not in an emergency-repair situation like on Main St.

Still, the guy with the GCMS taunts me…

I believe in knowing, because I know I don’t like believing…

[Dimbo_The_Blinky]

@Chloe

These look good , no? Nice and shiny… I hope they reply soon! :bigsmile:

Ooooo! You can buy through Alibaba? We should talk. I can’t touch the MOQ’s most of those guys need, even to quote a price. But I do think I could convert a lot of the stuff they list into ca$h locally…

But I’m the last one you should ask about a ‘store-bought’ 18650!! I only had two, “free” with a torch, and they weren’t worth the cost of electricity used to charge them. I’m a “laptop pulls” guy, especially with high-end brands like Dell & HP… The bigger the whale, the fresher the plankton. Dell gets first cut of whatever {manufacturer name} has to offer, and when the wee circuits fail, another batch falls almost directly into my hands, which seems to work well enough for me. I wish they’d use 14500s!!! I can’t prove this, but I believe that the ones that get left on docking stations or chargers seem to last longer, to tie in to a point in an earlier post…

Sorry, those “Nice and shiny…” ones do look good for the money.

[Dimbo_The_Blinky]

@Helios-

Careful Indie, the locals say there be some nasty snakes around.

They is too many Motherf&&&ing Snakes on this Motherf^ing Thread!

[Dimbo_The_Blinky]

@Helios-

AW tends to charge a lot.

Now that’s funny right there, I don’t care who you are!

I want the one that doesn’t charge at all.

After all, I am…

Dim!
(PS: I want a vacuum cleaner that really sucks!)

[KenCam]

I have worked with electricity for most of my life and always bear in mind the old adage; that it(electricity) is “a good servant but a bad master”. I know absolutely zip about lithium batteries but take the same approach i.e find out everything you can and then jump in once you know. I think you already know more than most!

[Dimbo_The_Blinky]

@KenCam

I have worked with electricity for most of my life

My brother! You will find many friends here!

I know absolutely zip about lithium batteries

This may help, or make your head explode:
Sony’s Lithium Ion Rechargeable Batteries Technical Handbook

It’s a start, anyway (and it was buried in a ridiculously long post).

Nice to meet you!

Dim