company news about Can lithium batteries of different capacities be connected in parallel?

Lithium batteries of different capacities can be connected in parallel, but they need to be operated carefully and meet certain conditions.

1.Theoretical feasibility

In principle, parallel connection of lithium batteries is feasible. Parallel connection can increase the total capacity while maintaining the same voltage. When lithium batteries of different capacities are connected in parallel, their terminal voltages should ideally be equal, so that after parallel connection, the output voltage of the entire battery pack is the same as that of a single battery.

2.potential risk

Capacity difference issue

The performance of lithium batteries with different capacities may vary during the charging and discharging process. Larger batteries may absorb more power during charging and output more power during discharging. This may lead to overcharging and discharging of batteries with smaller capacities, thereby affecting their lifespan and performance.
In the long run, batteries with small capacity may age faster and even experience damage.

Internal resistance difference issue

Lithium batteries of different capacities typically have varying internal resistances. When connected in parallel, batteries with lower internal resistance will bear more current, which may lead to more severe heating and even cause safety issues.
If there is a significant difference in internal resistance, it may also lead to uneven current distribution within the battery pack, affecting the performance and lifespan of the entire battery pack.

Consistency issue

Lithium batteries of different capacities may have differences in the production process, such as electrode materials, manufacturing processes, etc. These differences may lead to inconsistent battery performance, such as charge discharge curves, self discharge rates, etc. When used in parallel, these inconsistencies may affect each other, further exacerbating the instability of the battery pack.

3.Safety precautions

Try to choose lithium batteries of the same brand, model, and batch for parallel connection to ensure that their performance and parameters are as close as possible and reduce potential risks.
Before parallel connection, each lithium battery should be thoroughly tested and screened to ensure good performance, no damage, and no leakage issues.