The flashing pattern of the WF 139, which charges for a fraction of second before taking a voltage reading to decide if charging should continue, then charges for another fraction, then reads, flashing green with each cycle:
Are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no, are we there yet, no...