JuiceDefender samples some aspects of the device operation to provide you with a rough estimate of its effectiveness – a low battery life multiplier is often an indicator that something is wrong in your configuration.

It will take some time (several hours) after you first install JuiceDefender for the multiplier to be displayed – this is normal.

Sometimes the stats file gets corrupted (usually due to the JuiceDefender’s process being terminated unexpectedly) and JuiceDefender has to restart from scratch, but not to worry – the multiplier should come back soon enough.