9WaterpiCharging the Sensonic ® Professional Plus ToothbrushCharge for 24 hours before first use. All 3 charge indicator lights willstay on continuously when the unit is fully charged. A full charge will lastfor approximately 1 week of typical use (2 minutes of brushing twice a day).If the toothbrush is to be stored for an extended period of time (six monthsor more), be sure to fully charge it prior to storage.Recharge Indicator LightsCharge indicator lights will indicate level of battery charge forapproximately 10 seconds after use and after removal from the chargingbase, and will then turn off.Fully Charged2/3 Charged1/3 Charge life(recommend recharge)Unit will not operate if the bottom LED begins to blink rapidly.In order for the toothbrush to begin to work again, it must be placed on thecharger for approximately 1 hour.GETTING STARTED WITH YOUR SENSONIC ® PROFESSIONALPLUS TOOTHBRUSH