20Ah LiFePO4 5C aluminium cells for unbeatable $18 each (CA, USA)

Hey folks,

I am already going to buy a massive pile of 20Ah LiFePO4 (100A continuous, 160A 10sec) for a large 12V battery I am building for a different project (PM me if you are curious). I also plan to get some extra to build an esk8 battery.

I plan to do a 16s1p setup (48-51V, 20Ah, 100A, 2000W). It is pretty much equivalent to a 12s6p or 12s7p setup with Samsung 30Q cells. That is rather large, but at $288 not unreasonable (and same price as for 72xSamsung 30Q @$4). I will also use a balancing 100A BMS (+$80).

This is probably more interesting for people who have a lot of space under their deck or who want to mount a battery block over their truck/board.

I am posting this in case anyone (ideally from Bay Area, CA) wants to join in and share shipping costs. I basically already am getting a special group buy price from the start thanks to my other project - so not a group buy, but even better price.



  • LiFePO4 is probably the most reliable and high cycle life chemistry
  • Can use standard Battery bars to connect in series
  • rectangular alloy encasing for heat dissipation and easy stacking
  • good BMS


  • needs more volume than 18650 cells
  • overkill

Battery cells:



I’d love to see a super long range, FAST, AT board made with these. One layer stacked width wise vertically … ill just show you. 16S2P, on a haya lid, top side could have been trimmed back to make more room for feet comfortably but eh i’m tired.

PNG 11 11111 PNG PNG

Mmmmm! 200A with up to 320A burst, 2048 watt hours…


Dude! Nice design! Yeah, that would make… an EV, essentially.

What about having a more square pack up front and another in the back, with the cells upright, two or three wide? Like this you could use a lower deck and have enough room for feet if the deck is long.

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Haha huge power but nowhere left to stand! Maybe stack it for a seat. Nice to see the iron batteries in the Bay Area though. Maybe could stand on the batteries and just commit to that and go even longer


What ESC are u using that allows higher than the VESC’s… 13S??

escs have a voltage limit not cell count limit. lifepo (iron cells) have lower voltage per cell

Exactly! Any standard 100A dual VESC will do (with small fail margin). The nominal voltage of 16S LiFePO4 is about 51V.

The focbox Unity HAS A MAX of 12S… Although, you are right as the other batteries that I am considering as a strong possibility is series of 18 650 s… From power tool batteries.

What are you talkin about in regards to the iron batteries? Just the lithium ion phosphate?

Doesn’t MATTER. That’s 12s of regular lithium ion (lithium polymer) cells with a maximum charge voltage of 4.2V. 4.2*12=50.4v, which is the maximum safe voltage the focbox can handle.

LiFePO4 (lithium iron phosphate, or iron as hummie called them) cells like the ones above have a maximum charge voltage of 3.6V, so you can have 16 of them and reach the same maximum safe voltage level as a 12s pack of regular li-ion.

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If I were further ahead in my Mountain board build Id go for it… Unfortunately its the wrong time for me

EDIT: just saw 0.6KG per cell , thats 9.6KG for a 16s1p setup using these

50g per 18650 cell : 12s*7p *0.05Kg = 4.2 KG

equivalent to 12s7p 18650 cells sure, but +2x weight…

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Yeah, LiFePO4 are not very energy dense.

Iron batteries is just slang for Lithium Iron Phosphate cell based batteries. Or what was your question?

Density wise, they lose. Price wise - in this case same. But where they excel at is life cycles… You can get 4000 out of these.

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Yes. I understand all about lithium ion just wasn’t sure if I was missing anything… Currently, trying to find someone to build me a 12s made of Samsung 30qs with high discharge rate…

Have you considered getting higher discharge rated ones? Like 40Ts? I wonder why everyone sticks to 30Qs if they value discharge over cycles.

40Ts are significantly larger than 30Qs, so they won’t fit in some builds. There are better-performing 18650s (VTC6 comes to mind) but they’re generally more expensive. 30Q is just a good balance of value and performance.

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