When lithium batteries are connected in parallel, they can achieve the same amount of power through mutual balancing.
I. Parallel Connection Principle of Lithium Batteries
Connecting lithium batteries in parallel is a method to increase the number of batteries to improve both capacity and voltage. However, during parallel connection, if the capacity differences between the batteries are significant, battery imbalance can easily occur. This imbalance is caused by differences in charge/discharge rates and internal chemical reactions, leading to variations in capacity between the batteries.
II. Methods for Parallel Balancing of Lithium Batteries
To avoid battery imbalance, several measures need to be taken to balance them. The following are common methods for balancing lithium batteries in parallel:
1. Use an equalizer
Equalizers are a common method for balancing lithium batteries connected in parallel. An equalizer separates the battery packs and applies different loads to each battery, thus ensuring a more even distribution of charge. The biggest advantage of this method is its ability to quickly equalize the battery pack when voltage changes.
2. Use an external power supply
Using an external power source for battery equalization is a common but uneconomical method. In this method, an external power source is connected to each battery individually via an interface, thereby equalizing the battery charge. While this method achieves efficient equalization, it is very cumbersome to use.
3. Use internal equalization circuit
Some modern lithium-ion batteries have built-in balancing circuits. These circuits use an internal system to balance the battery. While this method is more automated, it also makes the battery more complex and increases its cost to some extent.
III. Summary
Connecting lithium batteries in parallel is a common way to increase capacity and voltage. However, imbalances between batteries often affect battery life and performance. To address this issue, several measures can be taken to balance the batteries, such as equalizers, external power supplies, and internal balancing circuits. It's important to note that even after implementing these methods, it's still necessary to periodically check the battery capacity balance.
