Defibrillator Volt

An AED delivers a 1000- to 2000-volt charge in less than 0.001 seconds. That's enough current to light a 100-watt bulb for 23 seconds.

How much voltage (volts) does a defibrillator have?

The central component of a defibrillator is a capacitor that stores electrical energy. In order to bring the heart muscle back into the normal beating rhythm with a targeted electrical current pulse (defibrillation), large-area electrodes are stuck to the chest of the affected person.


The current pulses of defibrillators differ slightly from manufacturer to manufacturer. The average values are as follows:

  • Voltages between 1,000 and 2,000 volts (V)
  • Initial currents of about 20 to 30 amperes (A)
  • Energy from 150 to 360 joules (J) for adults


A modern defibrillator works biphasically (with two phases). This means that during defibrillation the voltage alternates between the two electrodes. The positive pole becomes a negative pole and vice versa. The pole change saves energy and ensures effective use of the defibrillator. A biphasic "defi" is gentle on the heart and also on the skin due to the lower electrical current.