Battery longevity in the Aveir VR leadless pacemaker is primarily determined by:

• Pacing output energy per pulse, which depends on the voltage, pulse width, and impedance
• Frequency of pacing, i.e., how often the device delivers pulses (known as the pacing burden)

The energy per pacing pulse (E) is approximately calculated as:

Where:

• V is the output voltage (e.g., 2.5V or 3.5V)
• PW is the pulse width (in milliseconds)
• R is the lead impedance (typically ~500–1000 ohms)

Then, cumulative charge over time is:

Where I = V / R, giving:

The more often this pulse is delivered (higher pacing percentage), the faster the battery depletes. For example:

• At 100% pacing with high output (e.g., 3.5V), the battery may last 4–5 years
• At 25% pacing with low output (e.g., 2.5V), it may last 10–15 years

A 1V increase in output (from 2.5V to 3.5V) increases power usage by about 96% due to the square of voltage in the energy equation. This explains why your jump from 2.5V to 3.5V drastically reduced the battery estimate.