1 eV is 1.6x10-19 Joules. So, 1 Joule is 1 / 1.6x10-19 eV
You're talking about two different measurements. Voltage is not equal to current (amps) nor is there any correlation between the two. If you know the amount of watts the device uses, you can divide...
3.6 mega joules
Volts and Joules are completely different units. 1 J = 1kg * (m2/s2) 1 V = 1 J/C = (kg * m2) / (A * s3)
1 BTU = 1055 Joules