CC3D (more accurately, using Basic Attitude Estimation, called Complementary Filter sometimes) gives you a few seconds before it starts gyro calibration at power on. You can see that it is doing the calibration because the LED's blink fast.
For a test, make sure the quad stays very still while you plug a battery in and don't move it. See how long it takes before the LEDs start blinking fast. That is how long you have to get motionless after plugging the battery in. Also there is a safety feature. If it detects motion it starts over, but it can only detect larger motions since it is assuming the quad is motionless and any motion it sees is coming from uncalibrated gyros. The worst that can happen is that it is moves slowly during calibration.