Sometimes when I haven't driven in a few days and then I drive only a short distance, I notice that the battery only has 2 bars of charge but the motor is still drawing power from it as well as using the ICE to power the car. Even with no acceleration or large demand for power, I can't get the car to use the ICE to power the car by itself while charging the battery. Do you know what I mean? This is one of the keys to the "pulse and glide" technique, to drive gently and allow the ICE the charge the battery when it doesn't have enough juice for ev mode. Are there some times when the car wants to drain the battery to a certain point before allowing it to charge up again?
That's not really how it works. It recharges once warm-up is complete and when demand is lower. During warm up, acceleration or climbs it will still draw from the battery until you hit the 40% mark if the ECU determines that that will be most efficient.