Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Initial Volts (V)

Required number input.

Final Volts (V)

Required number input.

Elapsed Hours (h)

Required number input.

Average open-circuit voltage fall per hour over an observed self-discharge interval; assumes no external load. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Volts Per Hour (V/h)

The resulting volts per hour returned as a number.

• Supercapacitor energy and self-discharge models depend on capacitance tolerance, ESR, leakage that changes with voltage and time, balancing, temperature, aging, and safe cell voltage. A single RC model may poorly represent long-duration behavior.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Battery Internal Impedance

  Estimate DC battery internal resistance from the voltage drop between two load-current operating points measured over a short interval.

• Internal Resistance

  Estimate battery internal resistance from open-circuit voltage, loaded voltage, and load current.

• Battery Self Discharge Per Month

  Calculate one-month battery self-discharge percentage from stored charge before and after an approximately one-month rest; exclude external loads.