Lithium battery pack parallel protection

Are series and parallel connection of lithium batteries safe?

The series and parallel connection of lithium batteries is a key technology to increase voltage and capacity, but it also contains safety risks. This article will analyze in detail the principles, methods and precautions of series and parallel connection of lithium batteries to help you avoid potential risks and build a battery system correctly.

How to charge parallel lithium battery packs?

Specific principles must be followed when charging parallel lithium battery packs: Use a matching charger: The voltage must be suitable for the nominal voltage of the individual batteries. The current setting is reasonable: usually 0.2-0.5C of the total capacity after parallel connection.

How to ensure safety in a parallel battery system?

To ensure safety, parallel systems must: Use batteries with consistent parameters: same model, same batch, and same capacity. Add parallel protection device: Control the mutual charging current between batteries. Make sure to connect batteries in parallel in a fully charged state: fully charge each battery individually before initial connection.

What is lithium battery parallel connection?

Lithium battery parallel connection is to connect the positive poles of multiple batteries together, and the negative poles together, so that the total capacity can be increased while keeping the voltage unchanged.

What are the dangers of a parallel battery system?

The most common danger in parallel systems comes from the “cross-charge current” between batteries. When batteries with different voltages are connected in parallel, the high-voltage battery will discharge to the low-voltage battery, and the current depends on the voltage difference and internal resistance.

Are all 18650 batteries protected?

In industrial packs of parallel 18650 batteries (like in Tesla cars), is every single battery protected as well? The batteries used for the project are standard Samsung 25R 18650 2500mAh 20A ones. Balancing is unnecessary among parallel-connected cells, since they will self-balance.