The invention relates to a screening grouping method of echelon utilization type
lithium batteries, and belongs to the technical field of determination of parameters of the
lithium batteries. According to the technical scheme, the screening grouping method of the echelon utilization type
lithium batteries comprises the following steps: testing and calculating so as to obtain a battery dQ / dV-
V curve, analyzing
ageing reasons of return power batteries by adopting an ICA (Incremental Capacity Analysis) method, and firstly rejecting the return power batteries, negative active materials of which are lost; testing to obtain the capacities, ohmic
internal resistance, polarization internal resistancs and self-
discharge values of the echelon utilization type lithium batteries, and screening the batteries according to indexes; and regrouping the screened batteries. The screening grouping method of the echelon utilization type lithium batteries has the beneficial effects that serious declining batteries are rejected by screening the echelon utilization type lithium batteries so as to ensure that the echelon utilization grouping property of the batteries is not affected by individual damaged battery; the batteries which are similar in terms of capacity, ohmic
internal resistance and polarization
internal resistance are clustered together by using
a weighting k-means clustering method, and due to the setting of weights, the capacity
utilization rate of a battery group is ensured; the forming consistency of the echelon utilization type lithium batteries can be improved, and the service life of the echelon utilization type lithium batteries is prolonged.