Samsung 30T or 40T 12s4p 4WD better for Esk8?

High capacity cells rarly boasts a low price. discharge is of course taken into acount when chosing. Thought that was too obvious to mention.

Lol show me some tests of that and then we will talk. How on earth would 1 motor out perform 4? If the gearing on the 4 was stupid maybe. Just maybe but still that’s not gonna happen

Thats the point. There is no gearing on hubs.

Just repeating what everyone said, for now, none of this cells have an advantage for a regular build, the only place I see them being better only in a XS1P config, the rest, when you do the math for weight and volume they are worse, even you keep the price out of the discussion

That being said, I can’t wait for some people to crash their model 3 so we can get our hands on the cells, if the rumors of the cells being lower rated to increase cicle life are true, maybe them they are worth due to a bigger energy density

Or when the price of a 2X700 is the same as a 18650

Actually I’m very good at math. This topic has been discussed a lot, but it usually goes along the lines of trashing all cells but the 30Q, and saying how all others are over priced for what they are. NESE are for 18650 but I spoke to the owner and he said he could make them for larger cells. Ok so why exactly are 30Q’s better than the 40T in a 12s4p/12s5p? They’re 3000mAh and 15A, the 40T is 4000mAh and 30A. For the amount of space, and ignoring cost, how does a 30Q out perform the 40T in a 4WD build, or even a 2WD build? Just facts please?

Bro, if you wanna spend your Money. Spend it. Noone will stop you. Only good argument here is that you need the extra drain current for those hungry hubs.

(3000mah) 241 wh/kg, 3 euro/cell vs. (4000mah) 220 wh/kg, 9.3 euro/cell. Hvn’t even done the space calculation, but you’re good with math etc.

I’ve done the space calculations, and putting 18650’s doesn’t allow me to put enough cells to make it comparable. Also, your main point you made was cost related, so you’re clearly not good at reading instructions…

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If looking from math side of things:

18650 = π * 9^2 * 65 = 16540.48mm^3 21700 = π * 10.5^2 * 70 = 24245.24mm^3

So for 46% volume increase you get only 1Ah and 15A

so compared *S2P 30Q and *S1P 40T

xS2P 30Q = x * (2 * 16540.48) = x33080.96mm^3 = 6Ah 30A

xS1P 40T = x * 24245.24 = x24245.24mm^3 = 4Ah 30A

2P 30Q is 36% larger volume than single 1P 40T and you gain 50% more capacity than 40T so math explains really clearly why 2P 30Q is much better than 1P 40T it’s more efficient in volume and capacity than any other cells

P.S. don’t blame me if my math skills is bit out dated :smiley:

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just curious what enclosure / deck are you planning to work with? are you making your own? because most are made for 1850 cells.

Not sure what answer you’re looking for then. Feels like noone the ones given are good enough for you atm.

No your math is solid, but that would mean I’d need to essentially double my cells, and I’m trying to keep this a single stack, and as small as possible. Running 4WD with just a 12s4p/12s5p of 30Q’s I imagine would be rather under powered compared to the same setup with the 40T. Yes it is smaller, but only enough to where if I was running a 12s4p, then maybe I could squeeze it up to a 12s5p. Showing the area of these cells is helpful, but it doesn’t take into account the wasted space that isn’t getting used since they’re circular… That’s basically what I’m trying to say and why I believe that for the space and weight, the 40T would be the best performing cell for me.

I’m planning on using one of Hummies decks, and routing it out a bit to make some extra room in the enclosure, then possibly reinforcing it with a layer of CF or fiber glass.

I see so capacity for you isn’t a matter :wink:

Main concern is space, so fitting the most powerful cell in the smallest amount of space capable of running 4WD.

Question: is 20A for one focbox and one hub (x 4wd) enough?

Yes, but normally important thing is capacity for range, I highly doubt you even use 40% of your cell current in your first 1000km…

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Even if you account for the wasted space 30Qs give you more Wh/mm^3 than 40Ts The optimal packing for circles is the hexagonal packing which offers a density of 0.9069 (Wikipedia).

So it is only a factor you apply whatever is the size of the cell.

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I tried to do this with a 10s2p made of 26650 cells that where rated for 60a and it didn’t work. The voltage sag was very bad. The cells I used had great specs but no track record. I wasted money and a lot of effort on that venture. So I turned to Lipos with 60C rating and had much better success. So for a compact short range high discharge battery, I think that Lipos are still the best choice.

Most builders who want long range and longevity use 30Q’s because they have been proven to outperform there specs.

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  • 4wd should draw less (R * I²)
  • your battery max was 30A at 12S per focbox? (120/4)
  • when i drive my r2 (10S4P 30Q) 2wd i have no problems. My battery max is 30A per focbox

I cannot imagine that a hub will have problems in a 4wd setup… Why did it not work with your batteries? You have two more Motors and the same battery max amp?

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If you don’t give a shit about money If you can eliminate the Z axis by routing into your deck and not weaken it. If your enclosure’s better optimised for 21700 If you feel you really need that much discharge. If you can be sure voltage sag wont be a problem with your 40T pack. yeah you will be the beta tester.

If your NESE modules are certified for what? 5P * 30A = 150A (I would be surprised if they’re not hot @ 40A, but of course yours will be custom)

Then sure. go for it man :slight_smile:

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@uigiroux what do you want? Most power density in the smallest package without worrying about range?