Best deal for 3500mAh unprotected 18650 cells

Samsung 30Q has a big problem - high selfdischarge. Probability is increasing with utilization. Compare Samsung 30Q versus SONY VTC6 selfdischarge. Both cells are after the same cycle aging test.

Around how many cycles is the Samsung 30Q prior to it having a high-self-discharge?

Also, would you happen to have data for the new Samsung 30Q6-T (the newer variant/model that are manufactured in China)?

New 30Q cell at 100 % SOC shows little bit worse selfdischarge than other cells from the very beginning.

Probably is worsening gradually during using. The cells (30Q and VTC6) from comparative 72 hours test are after 700 cycles : charge 1A to 4,1 V, 0,1 A cut-off, discharge 2,5 A to 3,3 V.

Mooch´s accelerated life cycle test from gotlib´s link can be relevant for vaping maybe, but definitely not for flashlight. 4A charge and 15 A discharge are parameters to kill the cell early.
Have no data on the new 30Q6-T you mentioned.

thank you very much for your very precious information!
@docware thank you for your screenshot and graphic very interesting! :blush: so for my sofirn q8 you recommend me rather the sony vtc6 than the samsung 30q?

if so, would you know by chance where i can buy the cheap vtc6 shipped to France?

I definitely cannot recommend Samsung 30Q. There is too much info about 30Q high selfdischarge from various ebike forums.
In Europe is nkon considered to be trustworthy supplier :

You just must accept that Sony products doesn´t belong to „cheap“ category.

thanks to you

Just made quick look at sofirn q8. You need button top version for q8 flashlight. My previous link was flat top.

i had already found it thanks,but they are out of stock until 09 February 2021 :frowning:

No no, out of stock is flat top version. But you need button top version which is in stock .

no ,add 4
then click on ” add to cart ”

and you will see the message above :
” The requested quantity for “Sony / Murata Konion US18650VTC6 3000mAh - 30A button top” is not available. ”
they’ve been out of stock for several months, i don’t know what they’re doing,it annoys me and i wrote to them but no response from them

You have to be patient, your order is very small, therefore doesn´t have a priority.

no that’s not it :
if you live in USA maybe you see them : available on their site

but me from France, they wrote well :
US18650VTC6 3000mAh - 30A button top” is not available.

= out of stock
and i made a mistake :
i thought i read yesterday on their site that they would be available again on February 9 .Mut i was wrong :
it only concerns the ” flat top ” version
-For the button top they do not announce any availability date it’s worse than i thought! :weary:

Hmm, that´s bad.
I live in Europe, Czech republic.
You have an alternative option, LG HG2 button top. I checked that they are really in stock.
I recommend to use DPD for shipping, have wrong experiences with other options.

thank you,but the vtc6 are better :frowning: i hope that nkon will answer me it’s been 3 emails that i sent them and still nothing for several days :weary:

Do you have a soldering iron? If so, you can buy flat top VTC6 batteries and put a solder blob on the top of it, to make it a “button” top.

thank you for this information
yes i have a soldering iron
but li-ion batteries scare me a little….because i know they can be explosive with metallic objects in contact…finally that if they touch pole + and pole - at the same time…but hey it scares me anyway

if there is a youtube video, that will reassure me immediately…
but also, where to find the button top for purchase?

You don’t need to solder a “top”, you need to “melt the solder” on the top !
Check this thread.

thank you for your link
i saw the video and read the posts, and it’s very technical to do…temperature adjustment and welding time …if i badly solder the battery and then it charges badly …

apart from that i removed the plastic wrapper from 1 of my batteries Samsung 30Q who died.
Just to see how the ” button top ” is welded on it .
I bought them from 2 years ago

here are the pictures of my battery :slight_smile:

their welding methods are completely different….

the writings on it, i don’t know what that means, i would have liked to know the date of their manufacture

-I had read this post where the person said that you have to scratch the edge of the battery and if an inscription appears, it is that they are real batteries, no counterfeit :

and mine is a real one but i knew it because i was told that nkon are serious :slight_smile:

I just found this very simple solution: a magnetic button top that would simply land on it ? :\_t=gps-id:pcDetailBottomMoreOtherSeller,scm-url:1007.33416.205113.0,pvid:dbd732d4-9a48-4244-ada2-bcafa8682761,tpp_buckets:668%230%23209439%234_668%23888%233325%234_23416%230%23205113%234_23416%234721%2321967%23493_23416%234722%2321972%236_668%232846%238108%231977_668%232717%237561%23390_668%231000022185%231000066059%230_668%233422%2315392%23968_4452%230%23211409%230_4452%233474%2316498%23552_4452%234862%2322449%23737_4452%233098%239599%23860_4452%235108%2323442%23640_4452%233564%2316062%23635

but with this solution, will the battery charge well as original ? and also this magnetic button not being welded, it may move and that scares me a little….

I also found this other solution, but it is more complicated, to do spot welding ,change plastic wrapping of the battery and replace the ring…… you have to have the material and above all know-how :frowning:\_t=gps-id:pcDetailBottomMoreOtherSeller,scm-url:1007.33416.205113.0,pvid:dbd732d4-9a48-4244-ada2-bcafa8682761,tpp_buckets:668%230%23209439%234_668%23888%233325%234_23416%230%23205113%234_23416%234721%2321967%23493_23416%234722%2321972%236_668%232846%238108%231977_668%232717%237561%23390_668%231000022185%231000066059%230_668%233422%2315392%23968_4452%230%23211409%230_4452%233474%2316498%23552_4452%234862%2322449%23737_4452%233098%239599%23860_4452%235108%2323442%23640_4452%233564%2316062%23635

Regarding Sofirn/BLF Q8, Sofirn SP36/Anduril, Haikelite HK04 soda-can style lights that require multiple 18650 batteries — so far I’ve been using flat-top 18650s for them (unprotected button-tops are harder to find from my place, or they are lower-drain types like NCR18650B), but based on my experience with these lights:

- genuine Sanyo NCR18650GA (raised flat-top) work properly (make contact)

- genuine flat-top Sony VTC (VTC6/VTC5) work properly (make contact)

  • genuine flat-top LG HG2/MJ1 work properly (make contact)

- however, genuine Samsung 30Q / 35E, which have a bit recessed flat-top, may not always maintain proper contact on the above-mentioned lights, so I would not suggest to use them for these lights.

There’s mention about using magnets on flat-tops — I’ve been using such magnets for single-battery lights (or when 2 batteries in series) that require button-top to make contact with the positive side. But would not suggest using them for the soda-can lights, since these magnets can go out of position and possibly cause a short, which can mean batteries and/or flashlight get a short-circuit - in a not-so-worse case scenario, the spring inside the soda-can light may soften or melt (then disconnects the contact?)… In worse-case scenario, I’m not sure what might happen…