Features 1、Voltage Output: The battery development board supports 5V 3A or 3V 1A power supply output, as well as supports Micro USB 1.5A charging current. 2、Circuit Protection: Mobile power supply with built in battery protection IC, with overcurrent, overvoltage, undervoltage, and over temperature protection. 3、Applicable Range: This battery expansion board is mainly used for mobile power supply or other battery powered devices, which is efficient and practical. 4、4 Battery Capacity: This battery shield holder can install 4 pieces lithium batteries (not included) to ensure stable performance and high efficiency. 5、Accurate Installation: Pay attention to the positive and negative poles of the battery during installation, and there are clear markings on the circuit board. Specification Item Type: Battery Holder Material: PCB Battery: 4 x Lithium Battery (not included) Output Voltage: DC 5V 3A or DC 3V 1A Package List 1 x Battery Development Board