LiFePO4 cells, who uses them?

I updated post 4 with A123 vs 30Q data :slight_smile:

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Can you do 20700, 21700 and make it a sticky? :slight_smile: (I feel like 18650s win easily)

Yea the lower voltage starts to add up when building packs with a123 cells. My 8s pack come in at 29.4 which is the same as a 7s lithion.

it was maybe already said but the cycle life of the iron is about 4x more than for ion which is pretty awesome and makes the price much more reasonable.

the headway red cells are awesome with their bolt connectors and 200 amp ability. theres video of liveforphisics from endless-sphere over charging them and shooting them with his crossbow and other stuff

great piece of mind there. also really hard to damage them by over discharging and they pop back up

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I feel like I’ve alreadt done 21700 in a different thread. I’ll look for it. If not, I’ll try to get to it tonight. I keep meaning to do a full on wiki for batteries but I just don’t have the time.

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There’s also a video of him trying to prove how 18650 Li-ions are unsafe by overcharging them, hammering them, drilling them and doing more stuff to them I cannot remember. In the end the cell did not blow up. He still concluded that the cells were too dangerous to use.

He is extremely biased, even when experiments dont go his way, he manages to twist the data to support his theories…

His videos are very very entertaining though

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This is a trap in a way. For example, 12s2p A123 at $10/cell is $240. Money equivalent 30q pack is 10s7p ($240/$3.5 == 69 cells)?

The A123 pack is 198wh. The 30q pack is 777wh.

So you get almost 4x capacity in 30q, which offsets the 4x cycle life of A123.

Plus with 30q packs you typically don’t drain it all the way, and usually don’t need to charge to 4.2/cell, which can greatly increase cycle life.

Sorry @banjaxxed we’re derailing your anti-thread-derail thread.

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and they have a great discharge curve holding a higher voltage level before dropping off. better than ion.

or even better deal!!!: 17$ each http://evassemble.com/index.php?main_page=product_info&cPath=2&products_id=20

and that’s single cell price and they do packs.

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So the price of used harvested cells are 1.50 each and the price for new a123 cells are around 6.00. Also they don’t catch fire.

This seems misleading to me. New cells (“B” type) are around $9-10:

https://www.buya123products.com/goodsdetail.php?i=6

The older “A” type with less capacity can be found on ebay, at qty 60 or 100, for about $6 per cell, but they’re new old stock, sitting around on shelves for a few years.

If you have a source for new “B” cells link us up.

@hummie i don’t know why I hadn’t noticed those red Headways. But they’re HUUUGE! 38mm x 120mm (173.28cc assuming cube as above), 330g. Compared to 30q at 18mm x 65mm (21.8cc assuming cube as above) 47g. About 7 times bigger/heavier. Thicker than a double stack 18650. Gonna have to topmount on your deck with hella riser :slight_smile:

derail away, a pure stream of consciousness is always entertaining

those headways would get you shot in a portable body-belt pack, 12s1p = 4.32kg uuuufff. But cheap enough $200, weightwise against 12s3p 30Q…must check, checked, about 1.72kg…heavy man

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theres a photo somewhere I saw years ago on endless-sphere of a cnc’d aluminum deck with the red headways on the bottom sitting there exposed bolted on the deck somehow and it looked fantastic. they’re big but doable with the right deck.

I spent a lot of time designing a connector for those cells that would bolt to the board. could be really simple to both connect the cells and mount them to the deck…and I think no enclosure necessary with these like the set-up with the aluminum deck I was writing about above. I think it’s a super clean nice look. I like to see them

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I like the bolts, so easy

and then if the bolts connect to your own metal fixture that bolts into a deck would be super slick. maybe a cast copper bracket or something. It was so long ago I was going to do it I forget what I was going to do in the end but sure there’d be many ways to do it.

ah memory loss, such a curse, what were we talking about again?

Here are those boards and the thread associated.

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Funny how the threads titles are nearly identical.

What are those brown cylindrical lipo?!

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That battery and rail system is dope