• Default Alternative Text

    A guide to help you choose the UPS battery backup that works best for your needs.

    Default Alternative Text

    What is an Uninterruptible Power Supply (UPS)?

    An uninterruptible power supply (UPS), offers guaranteed power protection for connected electronics. When power is interrupted, or fluctuates outside safe levels, a UPS will instantly provide clean battery backup power and surge protection for plugged-in, sensitive equipment.

    APC, a flagship brand of Schneider Electric, offers UPS options for Computers & Peripherals, Networks & Servers, as well as Data Centers & Facilities.

    View all of our UPS products

    Need help choosing a UPS Battery Backup?

    Please use our UPS Selector to receive a customized UPS Battery Backup recommendation for your home or business.

    Why do you need a UPS in your home or business?

    Default Alternative Text

    Home: The electronic devices you rely on every day for communication, security and entertainment are at risk for damage and failure due to unexpected blackouts, voltage fluctuations or other power disruptions. A UPS provides battery backup power and protection for electronic devices, including:

    • Wireless networking equipment (routers, modems)
    • Computers
    • Televisions
    • Security systems
    • Gaming consoles
    • Mobile devices

    Learn more about our Home solutions

    Default Alternative Text

    Business: Downtime caused by power outages is frustrating for anyone, but can be financially crippling for a business or organization. Every year, billions of dollars are lost due to downtime caused by power disruptions that could have been prevented by a UPS. For Fortune 1000 companies:

    • Average annual cost of unplanned downtime, $1.25—$2.5 billion
    • Average hourly cost of infrastructure failure: $100,000
    • Average hourly cost of critical application failure: $500,000—$1 million

    Small to medium-sized businesses may be at most financial risk due to a limited ability to generate revenue during downtime.

    Learn more about our Business solutions

    Default Alternative Text

    What size UPS do you need?

    Electronics have both maximum watt ratings and maximum VA (volt-ampere) ratings. Neither rating may be exceeded by attached equipment. Watts measure real power drawn by the equipment, while volt-amps are the product of the voltage applied to the equipment times the current drawn by the equipment.

    For help sizing a UPS, please use our UPS Selector

    Default Alternative Text

    The Power Factor

    For computers and UPS units, watt and VA ratings can differ significantly, although VA rating is always equal to are larger than watt rating. The ratio of watts to VA is called the ‘power factor’ and is expressed either as a number (i.e. – 0.8) or a percentage (i.e. – 80%). When sizing a UPS for your specific requirements, the power factor matters most. Generally, your UPS should have an Output Watt Capacity 20-25% higher than the total power drawn by any attached equipment.

    To learn more about power factor, read our white paper

    Default Alternative Text

    How much runtime do you need to support your attached equipment?

    That depends on what you intend to backup with your UPS. Runtime refers to the amount of time a UPS will be able to power its attached equipment in the event of a power disruption. The more equipment you have plugged-in to your UPS, the less runtime you will have, so it’s important to make sure your UPS is only providing backup power to your most critical equipment.

    What are some key features to understand when choosing a UPS system?


    User-Replaceable Batteries - Increases availability by allowing trained users to perform battery upgrades and replacements.

    Surge-Only Outlets - Protect secondary electronics from surges and spikes without reducing battery power used to run primary electronics during outages. 

    Building Wiring Fault Indicator - LED indicator that informs users of potentially dangerous wiring problems in wall circuits.

    Transformer-Block Spaced Outlets - Protect equipment without blocking access to other receptacles.

    Automatic Self-Test - Periodic battery check that ensures early detection of batteries needing replacement.


    Automatic Voltage Regulation (AVR) - Gives high application availability by correcting low and high voltage conditions without using the battery.

    Pure Sine-Wave Output on Battery - Simulates utility power to provide the highest degree of compatibility for active PFC (power factor corrected) servers and sensitive electronics.

    SmartSlot - Customizes UPS capabilities with network management cards.

    Scalable Runtime - Allows additional runtime as needed via external battery packs.

    Power Conditioning - Protects connected loads from surges, spikes, lightning, and other power disturbances.


    Adjustable Voltage Transfer Points - Maximize useful battery life by widening the input voltage window or tightening the output voltage regulation.

    Temperature-Compensated Battery Charging - Prolongs battery life by regulating the charge voltage according to battery temperature.

    Intelligent Battery Management - Maximizes battery performance, life, and reliability through intelligent, precision charging.

    Predictive Failure Notifications - Provide early-warning fault analysis, ensuring proactive component replacement.

    Plug-and-Play External Batteries - Ensure clean, uninterrupted power when adding extra runtime to a UPS.

    • What power conditions will a UPS battery backup protect against?

      Many power problems originate in the commercial power grid, which, with its thousands of miles of transmission lines, is subject to damage from weather variations such as hurricanes, lightning storms, snow, ice, and flooding, as well as equipment failure and traffic accidents. Click through the slides to learn more about the types of power disturbances a UPS battery backup will protect your equipment against.

      Default Alternative Text
    • Transient

      Potentially the most damaging type of power disturbance; transients cause momentary variations in current, voltage, or frequency.

      Default Alternative Text
    • Interruption

      Power interruptions present a complete loss of supply voltage or load current.

      Default Alternative Text
    • Sag

      A reduction of AC voltage at a given frequency, sags are usually caused by heavy power draw at startup or by system faults.

      Default Alternative Text
    • Undervoltage

      Undervoltages are the result of long-term problems that create sags. Temporary decreases in power lasting up to over a minute.
      Also called brownouts.

      Default Alternative Text
    • Swell

      The reverse of a sag, characterized by an increase in AC voltage.
      High-impedance neutral connections and sudden load reductions are common sources.

      Default Alternative Text
    • Overvoltage

      An extended power swell or spike, overvoltages can be transient or permanent and may be hazardous. This is common in seasonal regions where communities reduce power usage during off-season.

      Default Alternative Text
    • Waveform distortion

      There are five types of waveform distortions:

      1. DC offset
      2. Harmonics
      3. Interharmonics
      4. Notching
      5. Noise

      Default Alternative Text
    • Frequency variation

      Changes in alternating current (AC) flows, frequency variations may occur with heavily loaded generators or poor power infrastructure.

      Default Alternative Text
    • Voltage fluctuation

      A series of voltage changes or cyclic variations of the voltage waveform envelope, generally below 25 Hz.

      Default Alternative Text
    • More Information

      For more information on the different types of power problems, please see our white paper, The Seven Types of Power Problems

      Default Alternative Text

      Computers and Peripherals

      Battery backup and surge protection for computers, home networking, external storage, gaming, home servers and more.

      Shop our products

      Networks and Servers

      Power availability and management for entry-level to high performance servers, storage, and business networking systems.


      Data Centers and Facilities

      Three-phase power protection with fully integrated solutions for enterprise-wide networks, data centers, mission-critical systems, and industrial / manufacturing processes.

      Explore our offer

      Special Applications

      Secure power systems for special single phase applications including industrial controls, renewable energy, marine, telecommunications and other configurations.

      View all options

      UPS Management

      Software, network management cards and peripherals for UPS management and safe system shutdown.

      For more details

      UPS Replacement Batteries

      Replacement battery cartridges (RBC) for Back-UPS, Smart-UPS and Smart-UPS On-Line.

      Find out more