LiFePO4 sources - Page 1
Forum section: electronics / general

author: artag
author_rank: Super Contributor
timestamp: July 22, 2022, 05:44:59 pm
content: I'm building a product that needs about 10Wh of rechargeable battery. A 3.3Ah Li-Ion 18650 would do nicely, but it seems LiFePO4 is the up and coming technology - allegedly safer and greener than Li-Ion.Where can I find good quality information such as recommended manufacturers, discharge curves, etc. ?UK buying sources are helpful but elsewhere is fine if there is a better place to get them.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 22, 2022, 06:13:55 pm
content: It seems you found some marketing material from year 2002.Anyway, the problem is not many reputable manufacturers do LFP chemistry. So you are left with crap tier random Chinese vendors like Winston Chung. Despite LFP being safer chemistry, it is not safe enough to allow ignorance of safety. Therefore, actual LFP products have worse safety record than high quality LCO, NCA or NMC cells.Low quality Chinese LCO/NCA is of course the worst possible deal.

author: KaneTW
author_rank: Frequent Contributor
timestamp: July 22, 2022, 06:26:38 pm
content: Speaking of:I'm struggling to find a supplier for NCA/NMC pouch cells for an upcoming product. The few Google results I contacted never replied; does anyone know a supplier? Talking 45-65Wh here, think laptop battery.

author: artag
author_rank: Super Contributor
timestamp: July 22, 2022, 06:31:57 pm
content: > It seems you found some marketing material from year 2002.Interesting, thanks. I did seem to find an unreasonable number of dead links and missing pages.

author: wraper
author_rank: Unknown
timestamp: July 22, 2022, 06:40:06 pm
content: You should buy LFP from Chinese manufacturers since they embraced the technology a while ago due to it being patent free if not shipped outside of China, end eventually became global leaders in LFP (China needs a LOT of batteries) while rest of the world chose other chemistries. AFAIK all LFP patents have just expired, so Chinese started actively exporting them.

author: wraper
author_rank: Unknown
timestamp: July 22, 2022, 06:42:40 pm
content: Quote from: Siwastaja on July 22, 2022, 06:13:55 pmSo CATL and BYD are not reputable enough?

author: JohanH
author_rank: Frequent Contributor
timestamp: July 25, 2022, 10:16:59 am
content: Quote from: wraper on July 22, 2022, 06:40:06 pmThis is very interesting and I noticed there are articles written about this:https://techcrunch.com/2022/06/26/why-lfp-batteries-are-poised-to-bring-down-entry-level-ev-prices/While googling about it, I saw that someone claimed that the last important patent expired in April 2022. If this is true, we should (hopefully) soon see more LFP batteries on the market. I think this is quite exciting.

author: JohanH
author_rank: Frequent Contributor
timestamp: July 25, 2022, 10:19:38 am
content: Quote from: Siwastaja on July 22, 2022, 06:13:55 pmI'm speculating now, but could this be due to the mentioned patents? I.e. there have only been a few licensed manufacturers of LFP batteries. If that is the case, this is possibly beginning to change now.

author: leon92
author_rank: Newbie
timestamp: August 06, 2022, 07:43:44 am
content: CATL, CALB, EVE, and Winston Battery are all the leading lifepo4 battery suppliers from China,You can find the information of single battery cells from Here:CATL batteryhttps://www.evlithium.com/CATL-Battery-cell/CALB Batteryhttps://www.evlithium.com/CALB_Battery/Winston Batteryhttps://www.evlithium.com/thunder-sky-winston-battery/

author: nvmR
author_rank: Regular Contributor
timestamp: August 06, 2022, 07:58:40 am
content: OP, I'm not sure about your volume, but consider buying hobby grade packs used in the RC model world. Stick an xt60/90 on your product and you're all set.I buy fromhttps://chinahobbyline.com/for example. They have several kinds of cells available with different discharge ratings.

author: wraper
author_rank: Unknown
timestamp: August 06, 2022, 08:02:22 am
content: Quote from: nvmR on August 06, 2022, 07:58:40 amThey are way too dangerous to use as general purpose battery inside a device.

author: gnif
author_rank: Unknown
timestamp: August 06, 2022, 08:15:17 am
content: I just bought a set of cells myself and there are many many dodgy sellers trying to peddle Grade B or worse cells as Grade A. I was almost bitten by this but after I demanded photos of the cells it was clear that they were Grade B as the manufacturer (EVE) laser etch a giant "B" over the battery QR code if it fails to qualify as Grade A. So be careful.In the end I managed to purchase 16x 304Ah Grade A cells from EVE direct, and they put me in-touch with a reputable company that they also use to weld studs onto the batteries as the 304Ah doesn't come with welded studs. Excluding import duty (which I am still waiting to pay as they are still on the boat) I managed to get the cells for $4000 AUD, including shipping, it did though take some haggling though to bring them down from nearly $6k.This all said, I have been using LiFePO4 21700 cells for smaller projects for a few years now and honestly they can't be beat both for simplicity of charging and safety. I'd never consider a Li-Po/Li-Ion chemistry for anything that needs to be "safe".

author: Siwastaja
author_rank: Super Contributor
timestamp: August 06, 2022, 11:37:39 am
content: Quote from: gnif on August 06, 2022, 08:15:17 am1) There is no such thing as "Li-Po chemistry",2) LiFePO4isli-ion.

author: gnif
author_rank: Unknown
timestamp: August 06, 2022, 11:55:36 am
content: Quote from: Siwastaja on August 06, 2022, 11:37:39 amSorry for not being more specific1) Li-Po is a generalisation of all lithium-ion cells using a polymer electrolyte which I would never consider for anything that I make/use that needs to be "safe".2) LiCoO2 (or most commonly referred to Li-Ion by the masses as it's the most commonly used and available). I avoid these cells for high energy applications such as UPS/powerwall applications in my home due to the dangers associated with them... again, this is MY personal choice, where I can I'd opt for LiFePO4 which are IMHO a far safer chemistry.Obviously LiFePO4 is Li-Ion

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 06, 2022, 12:58:34 pm
content: Have you looked at Battery Hookup?https://batteryhookup.com/products/20-pack-tested-21700-lifepo4-3-2v-cells

author: Siwastaja
author_rank: Super Contributor
timestamp: August 06, 2022, 01:37:58 pm
content: Quote from: gnif on August 06, 2022, 11:55:36 amAnd none are commercially available AFAIK. All li-ion cells sold to general public use liquid electrolyte. The polymer electrolyte thing never really took off albeit being discussed and tested in 1990's.Some manufacturers use the name, though, as some kind of inside joke or marketing thing. Polymer is only in packaging (plastic bag).

author: artag
author_rank: Super Contributor
timestamp: August 13, 2022, 04:28:53 pm
content: Thanks for all the information, folks. I have bought a couple from ebay, and some chargers to experiment with.I expect to use about 400 units/year, buying in 100s.