Rechargeable Battery Built-in-- Built-in 2200mAh lithium battery, you don't have to put or change batteries or find a place to plug it in anymore. It is a fully autonomous system that you can freely move around your yard or home. Once it is charged (using the simple USB to Mini USB cable that we provide), it can operate for up to 2 months. After that, you just have to recharge it again for 5 hours and you are all set for the next few months. Easy To Set This watering system is easy to set. Firstly, set the watering duration from 1~90s or from 2~3mins; then set the watering interval from 12 hours or from 1~10 days. Solve your daily work, take care of plants when traveling question.Automatic watering device can help you water on time every day, make the plants grow healthier and longer lasting, and make your life easier. Efficient WATER-SAVING DESIGN Automatic plant watering system combines the water time and pump to deliver proper amount of the water from the water bucket or water tank to max 4/8/12 potted plants.Saving 70% water compared to traditional spray and plant irrigation dripper, working more efficiently to save your time and water.