Rechargeable Battery The baby monitor uses a rechargeable Li-battery. It will alert when the parent unit's power is below a certain value. This will remind parents to recharge the battery and continue to care for their lovely baby. And in ECO mode, the operating time can last longer. ECO mode ECO mode is a VOX auto wake-up function, when baby is quiet, the screen will turn off the screen, but the sound still on; the screen will turn on when the baby cry or hum. You can select LOW/MID/HIGH to adjust the sensitive of sound-pickup. LOW means a small sound can also wake up the screen. Packing List 1 x 2.4GHz Camera 1 x 3.2" Receiver 1 x US Power Adapter for Camera 1 x US Power Adapter for Receiver 1 x user manual Notes: ★ This product contains small parts, please keep away from children. ★ Charging the parent unit fully before using, press the power-on switch to turn it on. ★ Place the baby unit in a suitable place and adjust the viewing angle of the camera until you are satisfied with the image in the parent unit.