How long can a lithium-ion battery UPS typically provide power? After a power outage, a lithium-ion battery UPS primarily relies on its battery energy storage to supply power to the load. The UPS has a built-in battery, and its power supply time after a power outage can range from tens of minutes to several hours.
The backup time of a lithium-ion battery UPS is determined by the UPS's energy storage device. The battery capacity is reflected by the "ampere-hours (AH)" rating, which indicates the time it takes to discharge at a specified current. For batteries with the same voltage, a higher AH rating indicates a larger capacity; for batteries with the same AH rating, a higher voltage indicates a larger capacity. Battery capacity is usually expressed using both voltage and AH rating, such as 12V/7AH, 12V/24AH, 12V/65AH, and 12V/100AH.
The calculation method for backup delay time of lithium-ion battery UPS power supply is: (battery capacity X battery operating voltage) / equipment power = extendable time (hours).
Lithium-ion battery UPS systems are categorized into standby, online, and line-interactive types based on their operating principles. These three types of UPS systems, operating on different principles, offer varying power supply methods and durations after a power outage. Today, we'll introduce the differences between these three types of lithium-ion battery UPS systems to help you choose the right one.
Backup lithium-ion battery UPS
Meaning: A standby lithium-ion battery UPS power supply directly supplies power to the load from the mains when the mains power is normal. When the mains power exceeds its operating range or there is a power outage, it switches to battery inverter power supply through a transfer switch.
Features: Simple structure, small size, low cost, narrow input voltage range, poor output voltage accuracy, has switching time, and the output waveform is generally square.
Applications: Standby lithium-ion battery UPS systems are primarily suitable for applications with minimal mains power fluctuations and low power quality requirements. The switching time of a standby lithium-ion battery UPS is generally less than 10 milliseconds, making it unsuitable for critical applications where uninterrupted power supply is unacceptable. However, in reality, the switching time is very short, and the switching power supply of a typical computer or electrical equipment should be able to maintain power for about 10 milliseconds during a power outage; the equipment generally will not experience problems due to this switching time. Standby UPS systems can only provide power for short periods.
Power supply time: The simple structure and small size of standby lithium-ion battery UPS means that the capacity of the lithium-ion battery inside the machine is also relatively small. Therefore, the power supply delay time of a typical standby lithium-ion battery UPS is generally less than half an hour, which is not suitable for supporting equipment to work for a long time after a power outage.
Online lithium-ion battery UPS
Meaning: When the mains power is normal, the online lithium-ion battery UPS power supply uses the mains power to rectify and supply DC voltage to the inverter, which then supplies AC power to the load. When the mains power is abnormal, the inverter is powered by the battery. The inverter is always in operation, ensuring uninterrupted output.
Features: Extremely wide input voltage range, no switching time, and high output voltage stability and accuracy, making it particularly suitable for applications with high power requirements; however, it is more expensive. Currently, almost all lithium-ion battery UPS systems with a power output greater than 3KVA are online lithium-ion battery UPS systems.
Applicable scenarios: Online lithium-ion battery UPS systems ensure that the AC voltage supplied to the load always passes through the inverter circuit, regardless of whether the mains voltage is normal or not, and the inverter is always operational. Therefore, when a power outage occurs, the UPS can immediately convert its stored electrical energy into AC power through the inverter to supply power to the load, thus achieving the goal of zero-interruption switching of output voltage.
Power supply time: Online lithium-ion battery UPS generally has a relatively large power, so its power supply time after a power outage is relatively long. A typical online lithium-ion battery UPS can provide power for several hours.
Online interactive lithium-ion battery UPS
Meaning: When the mains power is normal, the online interactive lithium-ion battery UPS power supply directly supplies power to the load from the mains power. When the mains power is too low or too high, it outputs power after being regulated by the internal voltage regulation circuit of the UPS. When the mains power is abnormal or there is a power outage, it switches to battery inverter power supply through a transfer switch.
Features: Wide input voltage range, low noise, small size, strong overload capacity (up to 200% overload capacity when powered by mains). However, it has a switching time and is not suitable for generator sets or environments with unstable mains power.
Applicable scenarios: When the mains power is abnormal, the inverter of the online interactive lithium-ion battery UPS immediately starts the inverter operation to convert the battery voltage into AC output. Therefore, online interactive UPS also has a conversion time.
Power supply time: The small size of online interactive lithium-ion battery UPS means that its power supply delay time is not very long. After a power outage, it can generally support the use of electrical equipment for about half an hour.
