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.
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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.
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,
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:
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
, which is still not “user-friendly”.
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
I don’t understand! :~ Did you want to do these tests?
These look good, no? Nice and shiny… I hope they reply soon! :bigsmile:
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. :~
Careful Indie, the locals say there be some nasty snakes around. 
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…
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.
They is too many Motherf&&&ing Snakes on this Motherf^ing Thread!
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!)
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!
My brother! You will find many friends here!
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
Let’s see what they say. It says they accept Paypal too.
This thread needs some kitties…
shudder
SOME day I’ll receive my 3400 Pannies from WB and let you know how they fit in the S5. 
the quote has been kept alive in fishinfools tagline for the last few years
You are more likely to be killed by a dead fish dropped by a seagull in the Sahara Desert than by a lithium ion cell going bad.
..Landshark .....
At 1,4A you are looking at Vf around 3,2. The Panasonic cell have not even started to dim when the Sanyo is out of juice. In terms of safety, its also better, because with the Sanyo, you go from full output to fully drained in no time. With the Panasonics you get more transition time at the end, and you get more time from the point when low voltage warning kicks in til the battery is empty.
The Panasonic is better in terms of maintaining higher vf in the first 50% of the Sanyos battery life, making it better suited for various high performance single cell lights too, in terms of output. I have seen the mentioned Panasonic deliver 0,3-0.8 amps more than the Sanyo with various driver/emitter combinations.
I normally look at the 5A curve. The panny keeps voltage above 3.5 for twice as long at that current.
Also, the s5 fits an ncr18650b better than the s6/xaiozhi. In the s6 it actually seals air inside.
I got a reply already from Efest Fest Company! Since I asked to pay by Paypal, and shipping airmail tracked:
So I am thinking to get some of these IMR as they’re really good price.