ITEM NAME:3S 25A 18650 Liion Lithium Battery BMS tection PCB Board 12.6V,Balance YK V U7Y7 Description&Preview.In use, the battery will heat up and the battery power is not applicable. Note 1: Connect 0V (B-), 3.7V (B1), 7.4V (B2), and 11.1V (B+) exactly as shown. Do not intentionally short-circuit! Explain: Don't mix good batteries and bad batteries together!