The utility model relates to a lithium ion energy storage unit and unique tuple through setting up battery management system, group battery and rather than the charging circuit of corresponding connection in that the energy storage unit is inside, realizes the integration that the battery charges and manage, the utility model discloses a short, the simple structure of energy storage unit interconnecting link, and easy the realization have effectively solved the current lithium ion battery peripheral hardware problem that machine, BMS lead to interconnecting link to break down easily of charging.