1. A method for measuring capacitance, comprising: at least partially discharging said capacitor and measuring the voltage thereacross to obtain an initial voltage; delivering one or more predetermined charge packets to accumulate a total charge on said capacitor thereby to generate a final voltage thereacross that exceeds a predetermined minimum voltage; and calculating said capacitance by subtracting the initial voltage from said final voltage to obtain a differential voltage, and dividing said total accumulated charge on said capacitor by said differential voltage.