The Working Principle of UPS Battery Float Charging And Boost Charging

UPS batteries are widely used across various industries including power supply, communications, banking, and any other industry requiring power sources. The performance of UPS batteries directly impacts their lifespan. There are two primary charging methods for UPS batteries: float charging and Boost charging. To prolong the lifespan of valve-regulated lead-acid (VRLA) batteries, it's essential to understand the characteristics and requirements of different charging methods and strictly adhere to them during the charging process.

Working Principles of Float Charging and Boost Charging for UPS Batteries

1. Float Charging:Float charging is a battery supply (discharge) mode where the battery is connected in parallel with the power line to the load circuit. The voltage remains relatively constant, slightly higher than the battery's open-circuit voltage. A small amount of current from the power line compensates for local losses in the battery, ensuring it remains in a fully charged state without overcharging.

Principle:When the battery is fully charged, the charger doesn't stop supplying power but continues providing a constant float charge voltage and a very small float charge current to the battery. This approach balances natural battery discharge. Small UPS systems typically employ float charging mode.

2. Boost Charging:Boost charging is a charging method used to balance the terminal voltage and specific gravity of each battery cell in a UPS battery set. It involves charging the battery with a constant current and over a certain period. The charging process is faster compared to float charging, and the charging voltage is higher. Boost charging is commonly used by professional maintenance personnel to maintain batteries and can help activate their chemical properties.

By understanding these charging methods, proper maintenance and charging of UPS batteries can be ensured, ultimately prolonging their lifespan.

Boost Charging Working Principle:Boost charging involves charging the battery with a constant current over a set period of time, resulting in a faster charging process. This charging mode is commonly used by professional maintenance personnel for UPS battery upkeep. Additionally, this mode can help activate the chemical properties of the battery.

Purpose of Boost Charging for UPS Batteries:

1.Rapidly replenish energy after battery discharge.

2.Eliminate voltage deviations among individual battery cells, promoting balance.

Purpose of Float Charging for UPS Batteries:

Float charging aims to maintain the battery at a fully charged state during standby operation, preventing overcharging and ensuring continuous availability in case of power outages.

1.Maintaining the battery voltage within the float voltage range slows down grid corrosion, extending battery life.

2.Replenishing the capacity loss caused by battery self-discharge to ensure sufficient power.

3.Inhibiting sulfate crystallization caused by active material recombination.

During float charging operation, each battery in the battery set may have different self-discharge rates due to the imbalance among cells, while the float charging current for the battery set remains consistent. As a result, some batteries may remain undercharged.

The above are the working principles of float charging and Boost charging for UPS batteries. Nowadays, most battery equipment such as UPS, EPS, and DC screens are equipped with automatic control for Boost and float charging voltages. However, to ensure optimal and prolonged usage of UPS batteries, it is necessary to regularly perform charge and discharge cycles during routine operation.