Method for combined use of various batteries

A method for combined use of different types of lithium ion batteries, comprising the following steps:

• (1) providing a first lithium ion battery set N={N1, N2, . . . , Ni}, wherein an ith lithium ion battery set Ni includes first lithium ion battery modules Si, i>1, and i is an integer;
• (2) setting a reference capacity C0;
• (3) selecting the first lithium ion battery modules having capacity greater than or equal to (C0−ΔC) and smaller than or equal to (C0+ΔC) after being fully charged from the first lithium ion battery set Ni and forming a second lithium ion battery set newN={newN1, newN2, . . . , newNk}, wherein 0.001≤ΔC/C0≤0.1, 1≤k≤i, and k is an integer;
• (4) selecting second lithium ion battery modules m from the second lithium ion battery set newNk and constituting a third lithium ion battery set useN={useN1, useN2, . . . , useN0} according to types of third lithium ion battery modules, wherein 1≤o≤k, o is an integer, oth third lithium ion battery set useNo includes the third lithium ion battery modules useSo, and m=ΣuseSo;
• and
• (5) adjusting the SOC of the third lithium ion battery modules, making the maximum SOC and the minimum SOC of the third lithium ion battery modules selected from the third lithium ion battery set useN meet |MaxSOC−MinSOC|≤ΔS, and then connecting the third lithium ion battery modules in series to form a battery pack for use, wherein 0.001≤ΔS≤0.1.