Can we talk about Prismatic LiFePo4 Cells?

The other day, some cat on here said he was planning to put a 10s5p on a board, that’s fifty batteries, the cell count alone complicates the whole build process. There has got to be a better way.

I’ve been checking out LiFePo4, and it seems to be good tech.

The battery folks love LiFePo4.

They tell me,

the flat prismatic cells are a more efficient shape for a battery than an 118650 cylinder.

  • but the cylinders seem way more popular.

They tell me,

LiFePo4 cells can have very high capacity,

  • and I see 3.2.v 20Ah cells everywhere.

They tell me

LiFePo4 packs don’t need a BMS,

  • but I see LiFePo4 BMS being sold.

They tell me

LiFePo4 batteries are less expensive,

  • and they sell them for less.

So why aren’t you using LiFePo4 prismatic cells?_

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Did you ever hold a 20Ah cell in your hand. I had a 38120 and they are heavy (and huge)!

The good LiFePo4s are the A123 26650 cells - but they are only 2500mAh and expensive

If you are talking about pouches i have never seen LiFePo4 pouches - where do you get some?


10ah lol @Maxid

Yeah exactly these ones - mine didn’t have the screw terminals though and were flat for spot welding. They are just 10Ah and I can only assume how big and heavy the 20Ah has to be :wink:

I seriously explored these for quite a while but figured cylinder cells were a better long term choice. The prismatic pouches seemed flakey to source and expensive for the 12 I needed. It was hard to get the right dimensions with the right capacity, and discharge/charge ratings. Any A123 products seemed B stock and were pricey.

I run an 8s lifepo4 setup with hobby king packs on my first build. They work well.

Food for thought…

My current build will use 26650 cells. They seem to have the specs I want and the cost is better than 18650 when comparing the pack build.

I use a 15S lifepo4 prismatic pouch pack (no BMS) on my ebike… have done for years I honestly don’t know why everyone here uses 18650s even lipos are better in terms of power/space density.

I still use lipos because they are the best value.


I use a 13s 1p A123 20ah prismatic in my scooter and a 7s in my skateboard. using for over 1.5 years. Both dont have bms. I have run down some cells to 0v and they revive like new. A123 is unkillable, most stable cells ever.

prismatics (the cell pouches) are hard to find in the dimensions you need them a lot of the time. At least that has been my experience.

I would love to move to prismatics as a way to increase energy density and move away from the steel cans that add weight. But prismatics are expensive and like i said hard to find in exactly the right dimensions you might need. 18650s are dead easy to work with, extremely flexible for layout, and thanks to the vaping community the prices just keep falling.

@leroy this is why for me; the demand for 18650 cells has increased volume and availability. I’d happily use LIFePo4 if they were readily available at comparable prices. I’ll eventually use A123 cells if a better option doesn’t present itself by the next time I do a battery build.

Also, lifepo4 cells have a lower voltage than lipo and li-ion, so you’ll need more cells in series for the same output.

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I doubt it was actually 0v… I’ve done that to a A123 cell, it never came back lol. It was damaged somehow.

Does A123 even produce them anymore? I can only find them on eBay and they are still expensive.

The industry will probably be switching to a 21700 or 20700 this year.

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@Pantologist they actually added an 18650 lifepo4. I wasn’t there there last time I was at their site a year ago… Not sure about how they are distributed or supply.

Interesting! Unfortunately their new 18650 is not really interesting for us. 30A Discharge is cool, but 1100mah is really not enough.

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Yeah the 26650 sizes are better but he was just saying that they are still active.


If anything, these cells with the screw type connectors would be the best for esk8.

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i’m looking at the sanyo 20700 4ah and 15A cont. 30A capable. still compact. decent price.

tests online show them beating out 25r and hg2 in voltage sag, and almost double capacity at high discharge.

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Yeah I was checking them out too. I’m waiting for Samsung, LG and Panasonic to release their cells.

I’m new to all this but find it all incredibly interesting.

As I have been trying to get a pulse on this industry and what is going on… do you have an idea of generally when others might release theirs? I ask in the hopes this is some sort of annual thing?

Seems like Samsung already has some available of this post by Mooch is legit.

Samsung INR21700-30T 35A 3000mAh testing by mountainprophet…a peek

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