18650 battery cell

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josh.qld
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18650 battery cell

Post by josh.qld » Sun, 17 Apr 2016, 15:22

Has anyone successfully purchased genuine 18650 cells from china?
Josh from Mackay

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mjcrow
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18650 battery cell

Post by mjcrow » Sun, 17 Apr 2016, 17:07

Hi,

I have purchased 18650 cells from www.fasttech.com and dx.com. Both provided genuine cells (Panasonic and Sanyo), but expect to pay more for genuine products. Please don't buy anything with "FIRE" in its name (eg, firepower, fandyfire, singfire, etc) the "fire" is in the name for a reason. I have purchased 26650 and 26700 cells from AliExpress but with mixed results, the bad - dead cells, the good - A123F1 cells that put out 600A each (for a few seconds).

Many of the quality cells are available in a protected form, good explanation here

The best places for reviews of sellers and cells in this size is flashlight and vape forums.

If I was in the market for cells now, I would buy from fasttech as they keep good stock levels of quality cells and package them well for shipping.

Just my 2c
Mike

josh.qld
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18650 battery cell

Post by josh.qld » Sun, 17 Apr 2016, 19:15

Thanks mike. i was thinking of getting small quanities sent over and bench testing them to see which are the good ones than going from there. The idea I'm chasing is what I've seen on the net with large banks of 18650 cells or similar to the tesla ev banks that are out. Im a leaky and all the motor and drive stuff i don't have a problem with but fining the right battery is going take me some time. do you know anyone who has done this or am i wasting my time? or is there a better way?
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Adverse Effects
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18650 battery cell

Post by Adverse Effects » Mon, 18 Apr 2016, 03:31

try these guys

liion wholesale
all + shipping and you need to email them about it

1 - 2. . .$ 4.99
3 - 24 . .$ 4.89
25 - 49 . $ 4.54
50 - 99 . $ 4.44
100 - 199 $ 4.34
200 - 499 $ 4.19
500 - + . $ 4.09

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mjcrow
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18650 battery cell

Post by mjcrow » Mon, 18 Apr 2016, 16:59

josh.qld wrote: Thanks mike. i was thinking of getting small quanities sent over and bench testing them to see which are the good ones than going from there. The idea I'm chasing is what I've seen on the net with large banks of 18650 cells or similar to the tesla ev banks that are out. Im a leaky and all the motor and drive stuff i don't have a problem with but fining the right battery is going take me some time. do you know anyone who has done this or am i wasting my time? or is there a better way?


Hi Josh,

What is the project, car? bike?

Mike

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Johny
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Post by Johny » Mon, 18 Apr 2016, 17:32

Just my 2 cents worth.
I notice that the cells adverse pointed at are only rated 6.8A max. continuous discharge rate. That's only 2C.
The Basen IMR 26650 cells on the same site (4500mAH) are rated to 40A continuous which make them around 9C - far more suitable for EV requirements.

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Post by Adverse Effects » Tue, 19 Apr 2016, 07:38

Johny wrote: Just my 2 cents worth.
I notice that the cells adverse pointed at are only rated 6.8A max. continuous discharge rate. That's only 2C.
The Basen IMR 26650 cells on the same site (4500mAH) are rated to 40A continuous which make them around 9C - far more suitable for EV requirements.


yes but he asked about 18650's so i gave him that info

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Post by Johny » Tue, 19 Apr 2016, 13:38

No worries adverse. Good site. I thought I'd better point out the low C rating just in case though. I like the 4500mAh cells they have.

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offgridQLD
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18650 battery cell

Post by offgridQLD » Tue, 19 Apr 2016, 14:20

Good timing I just stripped down a 18v 3ah power tool battery and was going to have a go at rebuilding it with 18650 cells of a higher AH and current handling. Looks like its just one or two cells that are letting it down. They are 6+ years old and look to be 2p configuration so only 1500mah cells. 10 cells in the pack.

Have to see if it's cost effective to rebuild vs a new battery. They want about $90 for a 4ah and about $150 for a 6ah emplacement. Need to start looking at the little bench size tab spot welder units to.

Thanks for the links.
Last edited by offgridQLD on Tue, 19 Apr 2016, 04:22, edited 1 time in total.

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mjcrow
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Post by mjcrow » Tue, 19 Apr 2016, 14:25

offgridQLD wrote: Need to start looking at the little bench size tab spot welder units to.


Zeva built a nice little welder with instructions here

Mike

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Adverse Effects
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18650 battery cell

Post by Adverse Effects » Tue, 19 Apr 2016, 14:44

mjcrow wrote:
offgridQLD wrote: Need to start looking at the little bench size tab spot welder units to.


Zeva built a nice little welder with instructions here

Mike


what ever you do dont buy one of These (or one like it i did and it exploded the 2nd time i turned it on and when i went to warranty it they told me i would have to pay for parts and shipping both ways (its like 3 1/2 Kg) back to manufacture

i was looking at making one of the Zeva ones but i know nothing about getting PCB's made and only know the very basic's of electronics (if all the parts where given to me i could easily assemble it just carnt work out how to get the PCB's done)

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mjcrow
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18650 battery cell

Post by mjcrow » Tue, 19 Apr 2016, 15:13

Adverse Effects wrote:i was looking at making one of the Zeva ones but i know nothing about getting PCB's made and only know the very basic's of electronics (if all the parts where given to me i could easily assemble it just carnt work out how to get the PCB's done)


Zeva has the Gerber files on the page and a link to Seeed Studio where he had them made, I would expect the cost to be around $60-70 (but check on their site) or so to have the PCB's made and shipped.

Mike

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18650 battery cell

Post by Richo » Thu, 21 Apr 2016, 21:15

josh.qld wrote: The idea I'm chasing is what I've seen on the net with large banks of 18650 cells or similar to the tesla ev banks that are out.
Telsa have a liquid cooled, individual cell protected battery pack.
I wouldn't recommend anyone doing the same for a hobby conversion.
If you want to just put 18650 cells together without the cooling or protection I definitely wouldn't recommend it.
josh.qld wrote:finding the right battery is going take me some time.
It is the biggest investment in an ev so taking the time to get it right is preferable.
josh.qld wrote: do you know anyone who has done this or am i wasting my time?
Hasn't been done in aus as far as I'm aware.
You'd be wasting your time in my opinion.
Even after Zeva got 18650, 26650 etc, did battery testing and built a batt welder he still didn't go down that path for his ev's.
josh.qld wrote:or is there a better way?
Well it depends on the application and performance
Motorbike - go with clamp down pouch cells or bolt on cylindrical (ie headway)
Daily car - go with bolt on cylindrical (ie headway) or prismatic (TS/Calib)
Performance car - same as motorbike

No welding needed.
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Adverse Effects
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18650 battery cell

Post by Adverse Effects » Thu, 21 Apr 2016, 22:57


Richo
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Post by Richo » Fri, 22 Apr 2016, 21:23

Johny wrote:The Basen IMR 26650 cells on the same site (4500mAH) are rated to 40A continuous which make them around 9C - far more suitable for EV requirements.

Adverse Effects wrote:yes but he asked about 18650's so i gave him that info
And the Samsung 18650 on the same site would be ok.

INR18650-30Q 5C
INR18650-25R 8C

https://www.powerstream.com/p/INR18650- ... asheet.pdf
Interesting the 20A cycle life to 80% is ~130. Image Image Image
Even if you made a guestimate and said 365 cycles to 80% on normal usage.
That is a pack a year. Image

USD$4,600 per 10kWh pack + shipping + duties + taxes for Samsung 18650
USD$6,200 per 10kWh for a headway pack.

You would have to buy FIVE 18650 packs for the same life as one headway pack.
So over the same life:
USD$23,000 18650 Samsung + shipping + duties + taxes
USD$6,200 headway

Not to mention triple the interconnection to build the 18650 pack.
Safety issues with chemistry blah blah blah..

Looking at the Panasonic datasheets the life cycle doesn't seem much better.

I don't see it.Image
Why would anybody consider using these cells for an eV?

And don't say because Tesla do it - Bah bahh bahh
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18650 battery cell

Post by jonescg » Fri, 22 Apr 2016, 22:38

Yeah, I'm just not seeing the cycle life you would hope for from these 18650 cells. There's always a catch - you can have energy density but not power. You can have power, but not energy density, and you can have both, but not cycle life.

Even LiPo pouch cells are quite good by comparison Image
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Adverse Effects
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Post by Adverse Effects » Sat, 23 Apr 2016, 01:52

i have some Panasonic NCR18650B i use for my ecig and it draws around 8Amps and i use 2 fully charged ones a day from 4.1V down to 3.2 and have been doing that for i am guessing just over 2 years and i check them on my expensive Lipo charger every now and then and they have lost almost no capacity so i dont see where the ~360 cycles are correct

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offgridQLD
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Post by offgridQLD » Sat, 23 Apr 2016, 03:30

With the Tesla model S and 80kwh+ of 18650's. That's a big bank so typically driving withi n the speed limits I would say the car would probably only be pulling 80kw or so from the motor 1C with short spikes of several C under acceleration.

So they can get away with it. That said I have read reports that the pack voltage on the model s sags like a 80 year old stripper under hard acceleration.



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Post by Richo » Tue, 26 Apr 2016, 21:33

Adverse Effects wrote:so I don't see where the ~360 cycles are correct


Well it is on the datasheet...
https://industrial.panasonic.com/cdbs/w ... 0CE417.pdf


Telsa's pack probably sags under load due to their premium per-cell protection.
And your right keeping it <1C by having a huge pack will help life.
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