Balanced discharge energy storage battery is a high-consistency series-parallel assembled energy storage battery designed to solve inconsistent discharge capacity, voltage difference and partial cell over-discharge faults of battery packs, applicable to large-capacity container energy storage, vehicle-mounted power batteries, off-grid solar energy storage and long-cycle standby power systems. In ordinary assembled battery packs, individual cells differ in internal resistance, capacity and aging degree due to production errors and service wear. During centralized discharge, weak cells will discharge excessively first, triggering overall pack power limit, accelerating cell attenuation and shortening the whole battery pack service life, which is the core failure cause of most large energy storage packs.

This product adopts dual active-passive integrated equalization technology to realize full-group synchronous balanced discharge. The passive equalization unit consumes excess electric energy of high-voltage cells through precision resistance during discharge, while the active equalization unit transfers redundant power from high-capacity cells to low-capacity cells via magnetic isolation energy transfer circuits. The whole process needs no external power control, realizing autonomous dynamic balance in the whole discharge stage. It controls the voltage difference between any single cells within 0.02V in the full discharge interval, eliminating the phenomenon that individual lagging cells restrict the overall discharge capacity of the battery pack.

Balanced discharge design brings comprehensive improvement in economic benefit and service performance of energy storage systems. Compared with ordinary battery packs with unbalanced discharge, its usable discharge capacity is increased by 12%-18%, avoiding residual electric energy waste caused by inconsistent cell cut-off voltage. It effectively prevents single-cell over-discharge, electrolyte decomposition and pole piece aging problems, extending the overall cycle life of the battery pack from 5000 cycles to 7200 cycles. Meanwhile, the built-in equalization module has low power consumption, with no extra energy loss during long-term operation. It supports series expansion of up to 32 strings of cells, compatible with high-voltage large-capacity energy storage cabinets, reducing later maintenance frequency, cell replacement cost and manual equalization debugging workload for energy storage stations greatly.