If the ESCs are parallel, then DrKnow is making sense. The motor wires would be parallel to one another, so I would imagine it would still put out 4s power, but split the current load between the two ESCs and batteries.

I see what you're thinking though, but I'm not positive that it works that way (two ESCs outputs equals double the voltage).

Someone else will probably have a better answer/explanation.

here's an explination. Let's say you have 2 12 volt car batteries. You are going to light a lightbulb and you want it to be lit with 24 volts. You also have 2 switches that are rated for 12 volts and will not handle 24volts even without a load. You take the first swith and put it on one side of the light bulb and the second switch on the second side. You run the first side to the positive of battery number one, and the second side to the negative of bettery number two. To complete the circuit you would need to connect the negative of battery number on to the positive of battery number two (creating 24volts). The moment you close the switches there are 24 volts going through the circuit and the switches fry.

Same scenario but instead of connecting the batteries in series, you connect one switch to the positive side of battery number one, and the second side to the positive side of battery number two. To complete the circuit you now connect both of the negative sides of the batteries togeather. You close the switches and the bulb does not light. Reason is, there is no potential between 12v+ and 12v+.

Now lets get real technical, you could put the two batteries in series, but now you are going to run one side of the lightbulb to the connector between the two batteries. The other side of the lightbulb is then "Y"d and a 12v switch put on either leg. Leg number one goes to the positive side of battery number one, and leg number two goes to the negative of battery number two (remember the positive of batt 2 is going to the negative of batt 1, and that is going to one side of the light bulb). If you close one switch you have 12v lighting the bulb. If you close the other you again have 12v lighting the bulb (although it is the opposite polarity). Everything works fine, but the bulb is dim (12v), so you close both switches and BANG you have created a dead short between the batteries.

If I'm missing something here I'm all ears. I could draw this out but I didn't want to risk offending anyone.