#Hack Chat, or the stack

Current flows if:

1 There is a voltage potentiental to drive it.

2 There is a circuit that allows the current to flow (back to the source).

Ohms law describes the relationship (i.e. I=V/R).

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So let us analysis the systems you describe:

Image 1 (an open circuit battery):

  3.7v potential

  Near infinite circuit resistance (i.e. open circuit)

  Result near zero current.

Image 2 (two batteries connected but still open circuit):

  2 x 3.7V pontential

  Near infinite resistance

  Result near zero current

Image 3 (short circuited battery):

  3.7V pontential (at least in theory if we assume the battery has no internal resistence)

  Near zero resistance (its a short circuit!)

  Result near infinite current (at least if we accept the assumptions above)

  Okay, the battery just blows up if it is a liPo!

Two batteries in parallel (not shown):

  Near zero voltage difference (well thats the assumption)

  Near zero circuit resistance (well that the assumption)

  Result? It depends but in practice for balance batteries, no current flows.

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But you do need to consider that batteries are not ideal voltage sources.

They have internal series resistance that limits the maximum current and internal parallel resistance that self-discharge the battery. These internal resistances are also non-linear, just to make it more complicated. That is why different battery chemistries have different battery charging methods (its not just the battery voltage).

Best of luck with you exploration of electronics.

AlanX