Parallel lithium battery loss balancing method, device and system

The invention discloses a parallel lithium battery loss balancing method, device and system which are applied to a battery switching assembly. The battery switching assembly is in communication connection with a battery detection assembly, the battery detection assembly is connected with a lithium battery pack, and the lithium battery pack comprises a plurality of lithium batteries connected in parallel. The method comprises the steps of acquiring electric energy data acquired by the battery detection assembly from each lithium battery; according to each piece of electric energy data and a preset voltage-residual electric quantity ratio relation table, determining electric quantity ratio information corresponding to each lithium battery; calculating the ratio of the electric quantity ratio information corresponding to any two lithium batteries as a loss difference value; determining a minimum loss threshold based on a comparison result of each piece of electric energy data and a quantization error correspondi