Everything You Need to Know About UPS & Batteries

Power interruptions, voltage spikes, and surges are more than just inconvenient—they can cause data loss, hardware damage, and costly downtime. An uninterruptible power supply (UPS) is designed to prevent these problems by providing instant backup power and power conditioning. But the effectiveness of a UPS depends heavily on its battery—the component that determines how long your system stays protected.

In this article, we'll cover everything you need to know about ups & batteries, including how they work, the types available, how to maintain them, and how to choose the right system for your needs.

 What Is a UPS?

A Uninterruptible Power Supply (UPS) is a device that provides emergency power to connected equipment when the main power source fails. It also protects against power surges, voltage sags, and electrical noise. A UPS typically includes:

• Inverter/Converter system to switch between battery and main power

• Battery bank for energy storage

• Bypass circuit for maintenance or overload scenarios

• Monitoring system for power status and alerts

UPS systems are used in homes, offices, data centers, hospitals, and industrial environments to ensure uptime and system integrity.

For example, AF93300 series Online Transformerless UPS 3 phase input and 3 phase output with a capacity covers various power ranges between 80kVA and 180kVA, which is convenient for users to flexibly configure.

 How UPS Batteries Work

The battery is the core of any UPS. When utility power is normal, the UPS charges its internal batteries. When power fails or fluctuates beyond safe thresholds, the battery kicks in instantly to supply power without interruption.

 Common Battery Technologies:

1. VRLA (Valve-Regulated Lead-Acid)  

•    Sealed and maintenance-free  

•    Most common in small and medium UPS systems  

•    Lifespan: 3–5 years  

•    Affordable and dependable

2. Lithium-Ion Batteries  

•    Longer lifespan (up to 10 years)  

•    Higher energy density and faster charging  

•    Lightweight but more expensive  

•    Increasingly used in high-end UPS systems

3. Flooded Lead-Acid Batteries  

•    Used in large, industrial UPS applications  

•    Require regular maintenance  

•    Suitable for long runtimes and scalable configurations

 Types of UPS Systems

UPS systems are categorized by how they manage power:

1. Offline/Standby UPS  

•    Switches to battery power when an outage is detected  

•    Suitable for home electronics and non-critical applications  

2. Line-Interactive UPS  

•    Regulates minor voltage fluctuations without switching to battery  

•    Ideal for small offices or areas with inconsistent power  

3. Online (Double Conversion) UPS  

•    Provides continuous power by converting AC to DC and back to AC  

•    Offers the highest level of protection  

•    - Used in data centers, hospitals, and mission-critical environments

 Key Features to Look For in UPS Batteries

• Runtime: How long the battery can supply power during an outage

• Recharge Time: How fast the battery recharges for the next use

• Temperature Tolerance: Batteries degrade faster in high temperatures

• Hot-Swappable Batteries: Allow replacements without shutting down the UPS

• Monitoring Tools: Indicators or software that show battery health and alerts

 Battery Maintenance and Replacement

UPS battery performance deteriorates over time. Proper care extends battery life and ensures reliability when it matters most.

 Best Practices:

• Test the battery regularly (at least twice a year)

• Keep the UPS in a cool, dry environment

• Replace batteries before failure—most show performance degradation before they fail completely

• Use genuine batteries from reputable brands

 When to Replace a UPS Battery

Warning signs that it’s time to replace your UPS battery include:

• Reduced backup time

• Frequent alarms or battery warnings

• Physical swelling or leakage

• The battery age exceeds 3–5 years (VRLA) or 8–10 years (lithium-ion)

Many modern UPS systems will alert you when battery performance drops below acceptable levels.

 Choosing the Right UPS and Battery System

When selecting a UPS, consider:

• Load capacity (VA/Watt rating): Should exceed the total load of connected devices by 20–30%

• Runtime needs: How long backup power is needed

• Environment: Indoor vs. industrial, temperature, and space constraints

• Scalability: Whether you may add more load or batteries in the future

• Monitoring and management features: Especially important in business and IT environments

Understanding the role of UPS and batteries is essential for protecting your devices from power disruptions. Whether you're safeguarding a single workstation or an entire network, the right UPS system and battery configuration will keep your operations secure, stable, and uninterrupted.