SMAKN&reg; 2A Mini Super Charging Circuit Board Support for single-cell lithium electricity / 2 serial / 3 series Support single lithium battery 4.2V, 2 string lithium battery 8.4V, 3 string lithium battery 12.6V (tp5000 only support a string, tp5100 support only 1-2 strings). *Input voltage: 4-20V (. The absolute maximum value 20V, we recommend less than 16V use must be greater than the charge output voltage). Synchronous Step-Down DC-DC ultra-high efficiency low heat. Do not install the battery can be converted into ordinary buck board. High frequency, low internal resistance.