What Are The Problems When Lithium Batteries Of Different Capacities Are Used Together?

If different capacities or old and new batteries are used together, there may be leakage, zero voltage, etc. This is due to the difference in capacity during charging, some batteries are overcharged during charging, some batteries are not fully charged, and batteries with high capacity are not discharged when discharged, while those with low capacity are over-discharged. In such a vicious circle, the battery is damaged and leaks or low (zero) voltage.