[Solved] Source for "button" or "flat" top 18650 Li-Ion

@zander I keep forgetting to do a quote.  Sorry about that.

@darup I think that last link you posted is a winner.

@darup Make sure you let us know how they work out.

I can't remember who was singling out @will and I as a scrounger... but thought I'd add this.  I was running out of 18650 cells as many are in projects.  A couple I plane wore out.  I also wanted to have several sets when doing my Inqling Jr testing (4x cells each set) and my future Inqling 3rd will be a power hungry beast (maybe 12x per set).  Nothing worse than being half done testing and no charged cells available.

Anyway... cracked open two old (dead) Dell laptop batteries.  I got them from last employer's bone yard that were about to be re-cycled.  They've been in my box for over six years and no telling how many years before then they were last charged.  Cracked open the first with 9 Panasonic cells.  Everyone of them was recoverable.  The second brick had 8 Samsung cells six were still holding a charge of 3.5V after those years sitting in a box.  Two were dead as a hammer and could not be recovered... Probably why the brick was unserviceable for a laptop any longer. 

15x 18650 top quality non-Chinese cells => $0

Posted by: @inq

I can't remember who was singling out @will and I as a scrounger...

I think I'm better known as a cheap bastard than as a scrounger 🙂 (Justifiably)

Where was I?  Anyone remember me?  It has been 11 months since I made an appearance.  I got off into drones leaving 18650 cells behind for a while. Then some time in ChaptGPT and the likes of other LLM! Played with AWK, c, Python, trying to rember what I forgot about APL and stuff like that.  "So, what's up?"  I notice I missed a lot of stuff.  Suppose I had better do my homework and take a check and see where my opinion might matter; or not!

@inq I was doing some old thread reading to familiarize myself with a recently active member and ran across this from my good friend Dennis(@inq). In post POST  I think what he said about LiFePO4 18650 cells is incorrect, they do indeed exist. I have 6 of the Battleborn LiFePO4 12.8V 100AH batteries in my RV. They are made up of a lot of 18650 LiFePO4 3.2V batteries arranged in a big series parallel arrangement thus the 12.8V.

LiIon are 3.7V 3,400maH LiFePO4 are 3.2V 1,200maH.

Chemistry means everything and results in tradeoffs. In the case of LiFePO4 you get much more safety at the expense of maH capacity but many more cycles as in 3,000 to 5,000+ cycles.

I am attaching a pic of your pertinent point, some PDFs from the Battleborn site under Learn.

I think I got this right, and I really really hope I do or Dennis will roast me something fierce.

@zander,

Hey!  I can't remember what I wrote/ate yesterday.  🤣  That post is over a year old!  Since then, I have long deferred posting battery comments to your obvious more in depth knowledge.  I use LiFePO4 cells of the 280 Ahr size in my boat for the safety reasons that I did extensive research.  I also verified with a discharge test at 0.5C and got 105% of the rated Ahr.

As far as this hobby, I use the 18650 LiIon batteries I scrounge out of old laptop bricks.  So it's obvious, I don't really have any reason to be hunting for 18650 cells on the Internet.  I do recall doing a search back then and only finding one source.  Doing a search today, there were a lot more options.

However, I wasn't really blown away by what I found.  As you have so often commented on this forum, there is a LOT of false advertising.  I even find it very surprising to find the 9900 mAhr LiIon 18650's on Amazon.  You can say what you want about Amazon's pricing, but with the instant, uncontested, free returns they offer, I would have thought such shenanigans would have been near impossible.  I attribute that to the average buyer ignorance found in the world that doesn't even have the ability to do a discharge test and that they are so shocked about how much better they are than NiCad or NiMH that they're satisfied with 10 or 20% of the advertised rating.  Even with that being said... there were very few adds for LiFePO4 18650's.  Like 1/1000 of the LiIon 18650.

Then I ran across this video and thought... I don't think I'd ever buy an 18650 LiFePO4!

I'll continue to scrounge (for free) Panasonic and Samsung cells out of deep pocket, name brand laptop computer companies (like Dell, HP, etc) that are scared to death of getting sued by a death caused by their battery catching fire.  Their QC on top of what Panasonic/Samsung already do must be extensive... at least as compared to some rotating, no-name (or bootlegged logo) stock of cells coming from Amazon, AliExpress or Banggood.

I usually cull my scrounged cells at 2000 mAhr measured capacity.  This is far better than any LiFePO4 18650 battery offers and that doesn't even take into account the energy density of 3.7/3.2V on top of the Ahr capacity.  

So although you are certainly correct... I wouldn't touch them with a ten foot pole and/or recommend 18650 LiFePO4 batteries to anyone else.  IMO.

VBR,

Inq

@inq Excellent reply. I think going forward, I will not advise anyone to buy LiFePO4 anymore since I do not know of a reliable supplier. The vast majority of cells on AliExpress and even Amazon (3rd party sellers) which is still Ali or similar with higher prices but faster (not by much) delivery.

The LiIon has a much higher capacity, but there is still a risk of fire or explosion if mishandled even from the most reputable supplier/manufacturer. It's inherent in the chemistry. For big power, I bought the large Li-Poly packs used by the RC community, and I bought a high-quality charger with balance leads to safely charge them inside my 2 (one inside the other) fireproof bags. They get charged OUTSIDE.

If it's not obvious, provide a disaster fuse as close to the battery + terminal as possible since a short can cause a current rush that may lead to a fire or explosion. I will employ two or even three different kinds of current interrupters, like a regular fuse (last) a slow blow, and some breaker. If you study the operating characteristics of each fuse/breaker style, you can tailor the fusing for maximum safety without nuisance interruptions. I know, half art, half science.

This is the classic case of TANSTAAFL.

https://amz.run/71rG

Posted by: @zander

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The LiIon has a much higher capacity, but there is still a risk of fire or explosion if mishandled even from the most reputable supplier/manufacturer. It's inherent in the chemistry. For big power, I bought the large Li-Poly packs used by the RC community, and I bought a high-quality charger with balance leads to safely charge them inside my 2 (one inside the other) fireproof bags. They get charged OUTSIDE.

I would ask if you can provide some up to date information on this.  Yes, there were some laptop, phone fires / explosions early-on (decades ago), but I haven't heard of any recently.  I assume most of these are associated with poor quality control, or over charging/discharging that they have since worked out.

I have never personally had an issue nor know anyone that has had an issue with an 18650 LiIon.  I also will be using a balancing BMS on my Inqster to supposedly keep it from over charging/discharging and balancing the cells.  With using (arguably old/used) A+ quality, true Panasonic / Samsung cells out of Dell laptops, I should be as safe as anyone and safer than most???

Also, I would not be so over enamored with LiPo.  In the last year, I have taken up RC aircraft at an active local club.  In the short space of a year, I have seen three LiPo batteries go up in flames by people that supposedly know better and spend big bucks on top quality monitoring chargers.  Just a data point for people on the forum.  

I think the main take-away for anyone that reads this thread.  ANYTHING with Lithium in it is dangerous.  Just be cautious and safe!

VBR,

Inq

@inq I also have not heard of any problems with LiIon for a very long time.

I think I was sloppy and lazy in my previous post and mixed up LiIon and LiPoly in my comments. Let me try to be more specific.

I have a few LiIon and regularly charge them with normal wall wart type chargers, usually 2.4A but sometimes only 1A and very rarely 3A. I don't recall any of them ever getting warm, and have never had any problems with them.

I have a pair of LiPoly, but I have not made extensive use of them as yet, I hope to next summer in one of several vehicles I am planning. As I have seen a few videos of that kind of battery going up in flames, I have advised getting a 'good' charger/balancer AND a fire bag plus a fireproof slab to charge them on. NOTE: I believe most if not all the fires reported were the result of low-quality chargers with bad engineering.

I think in summary, buying batteries from reliable vendors and using a high-quality charger will result in a safe experience. However, I would still practice good safety procedures like fireproof charging bags, fireproof slabs charging outside when possible and good ventilation when not possible.

After a few searches using differing words, the best I can find is that in 5 years there were 669 Lithium incidents in the cities of NYC and SF combined. That is 134 per year for 9.5M people. 

The bottom line is Lithium is dangerous. Buy carefully, and use quality chargers and procedures. I think the risk is tiny given all the many benefits.

Hi Ron @zander & @inq,

  About 5 years ago I did a quick literature search on batteries and trends ... this was looking at the 'professional' end, considering power/energy density levels for cars and bigger,  and only in terms of generic types, not suppliers .. rather different from  our everyday usage on this forum. The data available, was also a little historic, so reflecting maybe 5-10 years ago period, but with some forecasts and updates.

As it was a time limited exercise, I might have some things confused, and I'm writing this from an aging memory, so please treat with as many pinches of salt as you feel appropriate...but to the best of my understanding:

All of the battery types in consideration are Li-ion ... including LiFeSo4 ... they are all concerned with transfer of Li ions .. the most common battery types have different chemicals associated with them, and that gives them different characteristics.

Similarly, they all use polymer separators, so  Li-Po is not really a different battery type .. usually used to describe flat ones that have not been folded into cylinders or other 'prismatic' shapes.

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As it is well known, the energy density (Watt-hours per kilogram or Watt-hours per litre) is lower for LiFeSO4 than the likely alternatives, both in terms of lower amp-hours and lower voltage.

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The studies had about half a dozen different lithium based chemistry types. Some of these were reported to be in large scale usage by different car manufacturers, including LiFeSO4.

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With every battery, its temperature will increase when charging or discharging at a significant rate.

However, with the exception of LiFeSO4, if their temperature exceeded a certain 'critical' value for that battery type, then even completely stopping the charging/discharging will not be enough to stop it self-destructing.  Of course, temperature monitoring can often prevent this situation occurring, but if the critical  temperature is exceeded, perhaps due one cell internally shorting, and then heating its neighbours, resulting in a chain reaction is almost inevitable if cells are tightly packed without a massive cooling capability.

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In at least one study, LiFeSO4 also seemed to be capable of at least twice as many charge/discharge cycles as its alternatives, suggesting for applications like cars, provided  it was not repeatedly overstressed,  it should normally exceed the life of the vehicle.

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If a cell/small battery starts to overheat, immersing in water to cool it is often the best action.

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If it is emitting smoke/vapours, then these can be very toxic/lethal .. in tests, large amounts of toxic gases, including carbon monoxide were released, as well as fire risks, etc. Some of these gases are also very flammable.

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So an individual 18650 or similar incident is luckily quite rare, given the number presently in use. However the dangers increase with the scale of the battery.

Best wishes, Dave

@davee I am almost positive I have some LiFeSO4 batteries somewhere but when I google that I get nothing. Can you provide a link to some data?

Posted by: @davee

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All of the battery types in consideration are Li-ion ... including LiFeSo4

Posted by: @zander

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@davee I am almost positive I have some LiFeSO4 batteries somewhere but when I google that I get nothing. Can you provide a link to some data?

Dave, I think you meant LiFePO4 - Lithium Iron Phosphate.  

Posted by: @davee

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If a cell/small battery starts to overheat, immersing in water to cool it is often the best action.

Only if is not busted already - Remembering back from my college Chemistry... Lithium thrown into water is rather impressive!  💣  This alone gave me considerable thought since my use of LiFePO4 is in a boat.  One of the specifications of the LiFePO4 was that it was able to not do anything really bad if a nail was driven through the plates, actively shorting them.  But it never said what happens if you then dunked it down into ocean water.