Hi pf, Consider a D.C. circuit with a 5V battery and a 5 ohm resistor which will draw a current of 1A. If we ignore internal resistance then adding another battery in parallel will not change the current through the resistance (V=IR). What will happen is that each battery gets 0.5A each now and they last longer (twice as long). My question is what happens in a situation where the second battery you add in parallel is not the same. Keep the original situation above the same but now add a second battery in parallel which is 10V. Still ignoring internal resistance what happens to the voltage across the resistor and the current through it? Will the voltage across the resistor fluctuate since some of the Coulombs of charge will deliver 10J whilst others will deliver 5J? Thanks.