1.Ultra-small size design, easily embedded in smart wearable, micro-drone and other compact space 2.Constant current/constant voltage charging mode, to that the charging rate is maximized and to avoid the risk of overheating 3.Supports automatic re-charging function, to keep the lithium battery always in the best state 4.Accurate charging voltage 4.2V (1%), to protect the battery safety and prolong the service life of 5.Trickle charging threshold of 2.8V, to effectively protect the low battery back to a healthy state Product Name: Mini Li-ion Battery Charging Board Module Charging Current: 600mA Charging Voltage: DC 4.2V (1% accuracy) Trickle Charge Threshold: 2.8V Functional Characteristics: 1. Constant Current / Constant Voltage Charging Mode with Thermal Adjustment to Maximized Charging Rate while Avoiding Overheating 2. Charging Current Monitoring Output to Support Power Monitoring Monitor output 3. Automatic re-charge function Color: Black Material: PCB Package Contents: 5 x Type-c charging module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.