Comparing the Green Turnigy Graphene Lipos applying the maths above to give people a starting point for useing them as the power source of a Kweld
6Ah 7mOhm Resistance
5Ah 9mOhm Resistance
4Ah 10mOhm Resistance
3Ah 13mOhm Resistances
2.2Ah 10mOhm Resistance (this look to low to me)
1.4Ah 13mOhm Resistance (this look to low to me)
KWeld Resitance 42mOhm or 0.0042ohm
To push the minimum of 800a
0.0042ohm*800A=3.36V
3s is 11.1-3.36=7.74
7.74V/800A=0.009675=9.7mOhm
so in Theory a 3S battery up to 9.7mOhm is bare minimum the closest is the Green 4Ah Turnigy Graphene at 10mOhm as the BARE MINIMUM.
Ideally it wants to push 1500A
0.0042ohm*1500A=6.3V
3s is 11.1V-6.3V=4.8V
4.8V/1500A=0.0032ohm (3.2mOhm)
Triple Turnigy 5ah in Parallel
(1/9)+(1/9)+(1/9)=0.333
1/0.333=3mOhm
Triple Turnigy 4Ah in Parallel
(1/10)+(1/10)+(1/10)=0.3
1/0.3=3.3mOhm
Dule Turnigy 6ah in Parallel
(1/7)+(1/7)=0.286
1/0.286=3.5mOhm
As the maths show in terms of Green Turnigy Graphene 4ah is the bare minimum 12Ah is preferred
What I can confirm in parties is single 3s6ah dose 1200-1400amps and dule 3s6Ah (3s12Ah) dose 1600-1800Amps
Hope fully you can follow this and it adds some evidence to why x or y is the one that should work for people to make up there own minds.