Parallel : add mAh.
Series : add voltage
so you want 12s, 12 in series, 2p, 2 parallel. Let’s say 18650 is 3000 mah. You want 12 of those in series to make it 12s but it only has 3000 mah. So you need another 12s in PARALLEL to make it 3000 mah + 3000 mah = 6000.
So to your question, yes you would need 12 of them to make it 6s with 6000 mah.
The highest mah of any 18650 at the moment is 3500. Those ones you linked to are fake.
You should use either of the following cells in at least 2 parallel;
Samsung 30q 3000mah 15A cont. discharge (6000mah 30A)
LG HG2 3000mah 20A cont. discharge (6000mah 40A)
Sony Konion VT6 3120mah 30A cont. discharge (6240mah 60A)
You should get your cells from a reputable source, I suggest nkon.nl
It depends on the battery. If you get 30q cells, they’re about $4.00 a piece in quantity. You definitely need more than 2p with them, I wouldn’t go below 3p, and 4p would be even better. If you go with the absolute top of the line vtc6 cells, yes they’re a lot more expensive. You still need at least 2p to get a decent amount of current and range.
Also keep in mind that you’re running 4 6s packs, each 6000mah. To have a similar range with 18650s, you’ll need 12000mah and 12s, which is 12s4p.
Far as I know the chemistry is very similar the package is just different with some safety benefit on the side of 18650s in terms of controlled failure (place on the cell designed to blow out, that said I’ve seen plenty of 18650 boards on fire to let me know it’s not entirely safe). I see this much how I see virus protection on computers, it gives people a false sense of security and safety, these things are dangerous no matter what kind of shell you put the chemicals in.
(18/2)^2*65 * 3.14 = 16,532 mm^3 = 16.5cm^3
18650 Power Density (power per cm^3)
(3.7V*3Ah) / 16.5 mm^3 = 0.67 Wh/cm^3
Compare with Lipo 5S pack
1455041 = 300,000 mm^3 = 300cm^3
5S3.7V5Ah = 92.5Wh
92.5Wh/300 = 0.30Wh/cm^3
So in terms of energy density for volume you’re actually better off with 18650s, one thing to keep in mind here though is the packing space lost when stacking cells next to each other, if we assumed the 18650 is a rectangular cube instead it is:
181865 = 21,060 mm^3 or 21 cm^3 which brings the energy density down to .52Wh/cm^3 but still slightly better than a regular 30C LiPo pack.
Personally I use LiPo packs because they are cheaper and I have the equipment (a soldering iron) to remake the connections to wire them together without potentially damaging cells. Also started off with quadcopters before I got into the esk8 hobby so had the charger and knowledge/experience with the batteries.