Balanced charging refers to ensuring that each battery unit in a multi-battery system can be charged evenly to prevent imbalance between batteries. In rechargeable emergency lights, equalization charging is to optimize the performance of the battery pack, extend the life of the overall battery pack, and ensure system stability.

multi-battery system
Rechargeable emergency lights usually use multi-cell designs to increase overall battery capacity and battery life. These battery cells form a battery pack, and the application of balanced charging technology is mainly targeted at this battery pack.

Battery imbalance problem
When multiple cells are used to form a battery pack, due to battery manufacturing, aging, usage history, etc., there may be certain voltage and capacity differences between different battery units, that is, battery imbalance. If not handled in time, this imbalance may cause some units in the battery to be overcharged and other units to be overdischarged. In severe cases, it may cause battery damage, performance degradation, and even safety hazards.

Balanced charging principle
The balanced charging system monitors each unit in the battery pack and adjusts the charging current to maintain a relative balance between the voltage and capacity of each unit within a safe range. Balanced charging systems usually include balancing circuits and control algorithms.
Balancing circuit: This is a circuit used to regulate the battery charging current and usually includes components such as discharge diodes, MOSFET switches, and current sensors. The balancing circuit can adjust the charging current of each battery cell according to its status to achieve balanced charging.
Control algorithm: The control algorithm is the intelligent core of the balanced charging system. It is based on real-time monitoring and analysis of the status of the battery pack, and maintains the voltage and capacity of each battery unit in a relatively balanced state by adjusting the control signals in the balancing circuit.

Active and passive equalization charging
In balancing charging, there are two common implementation methods: active balancing and passive balancing.
Active balanced charging: This method actively adjusts the charging current of the battery cells to ensure that each battery unit is in a relatively balanced state. Active balancing charging typically requires additional circuitry and control systems, but provides more flexibility for precise adjustments to individual cells.
Passive balancing charging: This method achieves balancing by blocking the charging current from flowing through battery cells with higher voltages when the battery pack is being charged. Passive equalization charging is relatively simple and low-cost, but may not be as accurate and flexible as active methods.