A: First, please ensure the battery contacts are properly connected (see Q2 above). Second, this is an intentional design for the product. Since we use two NiMH batteries, the battery level is detected by the voltage. To prevent overcharge and increase both battery life and charging stability, the battery display may show that the batteries are not fully charged. Usually the batteries will charge all the way to 100%, but the Quest may still display it at 90% or lower. Don’t worry, this is completely normal. Third, the controller batteries last much longer than the headset. You won't have the controllers running out of battery during normal use.