The utility model discloses a battery pack, including a plurality of battery modules, cooling system and BMS system, the battery module includes a plurality of electric cores, support, serpentine pipe, busbar, insulation board and aluminium backup pad, cooling system includes front end -plate, both sides business turn over water pipe and water pipe fixing base, both sides business turn over waterpipe includes left inlet tube, left outlet pipe, right water inlet pipe, right outlet pipe, the BMS system includes BCU and BDU. The utility model provides an overall arrangement mode of battery module, cooling system and BMS system, under the prerequisite of guaranteeing battery pack safe and reliable, improvement battery pack's the life -span that recycles, the effectual installation degree of difficulty that has reduced, reduction in production cost, improvement production efficiency.