Battery Equivalents and Replacements

Best UPS Battery Backup For Computer

A computer Uninterruptible Power Supply (UPS) is a vital device designed to provide immediate power during outages or fluctuations, ensuring the continuous operation of connected equipment.

By acting as a bridge between the main power source and the computer, it safeguards against potential data loss and hardware damage that can arise from sudden power disruptions.

For anyone relying on computers for critical tasks, a UPS is an indispensable tool for maintaining both productivity and peace of mind.

Published: October 16, 2023.

Given their features, UPS systems are ideal for critical infrastructure and equipment, such as computers, servers, and medical devices.

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The immediate switch-over and power-quality features safeguard against data loss and equipment damage. Basic battery backups, while also useful, might be better suited for less sensitive equipment where a few seconds of delay in power provision is acceptable.

Best UPS For Computers And Laptops

With a rather larger number of models on the market, we picked up only these models.

It wasn't easy, but these models offer probably the best features at the most acceptable prices. And they are not the cheapest units on the market.

If you need just basic UPS protection, there are smaller and cheaper units.

Before buying any device, check its features and performances, but also reviews by other users.

CyberPower CP1500AVRLCD3 1500VA/900W Intelligent LCD UPS System

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CyberPower CP1500AVRLCD3 is a successor of the still very popular CyberPower CP1500PFCLCD UPS.

CyberPower CP1500AVRLCD3 uses simulated sine wave output to protect computers, laptops, and other sensitive devices.

Its maximum power is 900W/1500VA and is provided via:

  • 6 (six) NEMA 5-15R battery backup and surge-protected outlets,
  • 6 (six) NEMA 5-15R surge-protected outlets.

Also, it comes with 2 (two) USB charging ports (1x USB-A, 1x USB-C) to help users charge their smartphones, tablets, etc.

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Surge protection offers protection up to 1500 Joules.

To provide additional protection to sensitive equipment, CyberPower CP1500AVRLCD3 also features AVR (Automatic Voltage Regulation), which corrects smaller voltage fluctuations.

LCD screen is easy to read, and it provides immediate information about the unit's status.

The maximum runtime of the unit is ~12 minutes under a half load and 3 minutes under a full load - runtime under a full load could be longer, but that is typical in this class, and it allows the user to wait 10-20 seconds after power failure and, if required, to properly shut down the computer.

If the load is light, for example, a laptop with 1-2 external monitors, the runtime is much longer.

CyberPower CP1500AVRLCD3 comes with a 3-year warranty. The physical dimensions of the unit are 13.78 x 3.94 x 10.2 inches (~35 x 10 x 25.9 cm) and it weighs only 10.8 pounds (~4.9 kg).

For more reviews and recommendations, feel free to check the CyberPower CP1500AVRLCD3 1500VA/900W Intelligent LCD UPS System and CyberPower CP1500PFCLCD 1500VA/1000W PFC Sinewave UPS System Amazon links (the links open in the new windows).

APC BR1500MS2 1500VA Sine Wave AVR UPS Battery Backup

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APC BR1500MS2 1500VA Sine Wave AVR UPS Battery Backup unit is another very popular computer UPS that has been tried and tested by numerous users.

Maximum output power is 1500VA/900W and is provided via:

  • 6 (six) NEMA 5-15R battery backup and surge-protected outlets,
  • 4 (four) NEMA 5-15R surge-protected outlets.

Also, the unit features one USB-A and one USB-C charging port with a maximum combined output power of 15 Watts.

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APC BR1500MS2 features sine wave output, additionally protected by the built-in AVR - an excellent choice for computers, laptops, and similar sensitive equipment.

LCD display is set under an angle, allowing the user to easily read all the required information, even if the unit is placed low, for example, on the floor.

Maximum runtime depends on the load - for example, at 100W, the runtime is 1h 17 minutes(!), with a fully charged, new battery.

The unit's physical dimensions are 14.49 x 3.94 x 10.24 inches (~36.8 x 10 x 26 cm), and it weighs 27.6 pounds (~12.5 kg).

If you are looking for a UPS that will not be moved around, this unit might be the best choice for you.

For more reviews and recommendations, feel free to check the APC BR1500MS2 1500VA Sine Wave AVR UPS Battery Backup Amazon link (the link opens in the new window).

Obviously, as said before, there are many other models on the market, but these two stand out from the crowd. IMHO, of course.

UPS vs. Battery Backup: Are They The Same?

When researching the realm of electronic power solutions, it's not uncommon to come across the terms "UPS" and "battery backup."

Both of these devices offer a lifeline in situations where power disruptions can mean the difference between a productive day and one filled with lost data or equipment damage. Yet, despite their similarities, they are not entirely interchangeable. Understanding the differences between the two is paramount for making an informed decision.

Definition and Basic Functionality

At its core, a Uninterruptible Power Supply (UPS) is a device designed to provide immediate power to electronic equipment during short power outages or fluctuations. Essentially, it acts as a bridge between the main power source and the connected device, ensuring that the latter remains operational for a certain period, even in the absence of external power.

On the other hand, a "battery backup" usually refers to a system that stores power in a battery and provides it to a device when the main power source fails.

At a glance, it might seem that a UPS and a battery backup are identical, but they are not. However, to provide backup power for computers (desktops, laptops, servers, etc.), Uninterruptible Power Supplies (UPS) are used, thanks to their better protection.

Thus, when talking about battery backups and UPS devices for computers, these two terms are used interchangeably, but in most cases, we are discussing UPS devices unless stated otherwise.

Advanced Features of UPS Systems

UPS systems come equipped with advanced features that are absent in basic battery backups.

These features include voltage regulation, power filtering, and surge protection.

These capabilities ensure that not only is power supplied during outages, but it's also of high quality. Voltage fluctuations, which are common during power disruptions, can be detrimental to sensitive electronic equipment.

A UPS ensures that the power being fed to the devices is consistent and free from such harmful fluctuations.

Response Time and Duration

The major advantage of a UPS over a simple battery backup is its instantaneous response time. When there's a power disruption, a UPS kicks in without any perceivable delay, safeguarding your equipment and data. A regular battery backup might not provide this instant switch-over.

Additionally, while both UPS systems and battery backups offer power for a limited duration, the focus of a UPS is often on providing immediate power for a short duration, allowing users to save their work and shut down their equipment safely.

Battery backups might be designed to last longer, serving equipment that doesn't necessarily need instant switch-over but benefits from prolonged power availability.

If one needs a UPS for a computer with a longer runtime, go for the model with additional external batteries, which often allow much longer operation while mains power is gone.

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Types of UPS

UPS devices differ in many features, including how they actually operate. For computers, laptops, servers, medical equipment, and similar sensitive devices, one should opt for Online (Double Conversion) or a similar UPS device, which offers a practically instantaneous response.

Standby (Offline) UPS

  • Operation: The primary power source directly powers the connected devices. The UPS only intervenes when it detects a power failure.
  • Switching Time: Typically, there's a short delay (milliseconds to a few seconds) before the UPS starts supplying power, making it suitable for non-critical applications.

Line-Interactive UPS

  • Operation: Features an interactive inverter that can either add or subtract coils from the main power line, thus regulating voltage without using the stored battery power. It bridges the gap between standby and online systems.
  • Switching Time: Its transition to the battery is faster than the standby UPS but might still have a slight delay.

Online (Double Conversion) UPS

  • Operation: Continuously powers connected devices from its internal battery while simultaneously charging the battery using the main power. This dual operation guarantees that there's zero transfer time to the battery during an outage.
  • Switching Time: Instantaneous. Since the devices are always running off the battery, there's no need for a transition, making it ideal for highly sensitive equipment.

Delta Conversion Online UPS

  • Operation: Similar to the double conversion, but with a delta converter to support the output voltage. This allows for more efficient power transfer and is typically seen in larger installations.
  • Switching Time: As with the double conversion UPS, the switching time is instantaneous, ensuring maximum protection for sensitive devices.

Ferroresonant UPS

  • Operation: Uses a ferroresonant transformer to buffer the output and regulate the power, providing a degree of line smoothing and backup protection.
  • Switching Time: Has a slight delay but is generally faster than basic standby systems, striking a balance between performance and protection.

Computer UPS Required Power and Stored Energy

When considering the implementation of an Uninterruptible Power Supply (UPS) for your equipment, two critical parameters to evaluate are the required power and the stored energy.

These metrics determine both the instantaneous power delivery and the duration for which the UPS can support the equipment during an outage.

Required Power (Capacity)

  • Definition: This refers to the maximum load a UPS can support, typically measured in volt-amperes (VA) and/or watts (W). While VA represents the apparent power, watts indicate the real power used by devices. It's essential to ensure that the UPS's capacity exceeds the total power requirement of all connected devices by some safety margin.
  • Choosing the Right Power: When selecting a UPS, sum up the power ratings (in VA and W) of all devices that you plan to connect. It's advisable to choose a UPS with a capacity of at least 25-30% more than the calculated total VA and W.

Stored Energy (Battery Runtime)

  • Definition: Stored energy indicates the duration for which a UPS can provide power to connected devices during an outage. This metric is contingent on the battery's capacity and is usually measured in watt-hours (Wh) or ampere-hours (Ah).
  • Factors Influencing Runtime: The UPS battery's runtime is influenced by the load's size, the battery's capacity, and its age. A heavier load will deplete the battery faster, reducing the runtime. Similarly, as batteries age, their capacity to hold a charge diminishes, leading to decreased runtimes.
  • Evaluating Needs: For mission-critical systems, having extended runtime might be crucial, allowing operations to continue during extended outages or providing ample time for safe equipment shutdown. In such cases, larger batteries or additional battery packs might be needed.

Balancing Power and Runtime

  • Trade-offs: There's often a trade-off between the UPS size (power capacity) and its runtime. A UPS capable of handling a larger load may not necessarily have a long runtime if it uses the same battery as a smaller UPS. Conversely, a UPS designed for extended runtime might not be equipped to handle very high loads.
  • Expansion Options: Some UPS models offer the flexibility to add external battery packs. This can be an effective strategy to extend runtime without compromising on the power capacity.

Other UPS Features

In addition to the essential power capacity and battery runtime, modern Uninterruptible Power Supply (UPS) units come equipped with a variety of additional features that can significantly enhance their utility and protection capabilities.

Number of AC and USB Ports

  • A UPS typically provides multiple AC outlets to connect various devices. Depending on your needs, you might opt for a UPS with more or fewer outlets.
  • Modern UPS systems may also incorporate USB ports, allowing for the charging and protection of devices like smartphones, tablets, or other USB-powered gadgets.

Pure Sine Wave vs. Modified Sine Wave

  • Pure Sine Wave: Delivers power in a smooth sinusoidal wave, mimicking utility power. It's preferable for sensitive electronics and devices like computers and certain medical equipment, as it ensures optimal performance and longevity.
  • Modified Sine Wave: Produces a more block-shaped waveform. While it's generally more affordable than pure sine wave UPS systems, some sensitive devices may not operate as efficiently or might produce humming noises under this power type.

Surge Protection

  • Let-Through Voltage: The voltage level at which the UPS starts diverting excess voltage away from connected devices. Lower let-through voltages typically offer better protection.
  • Clamping Voltage: The voltage level at which the UPS will actively clamp or suppress a surge to prevent it from passing through to connected devices.
  • Joule Rating: Represents the total energy absorption capacity of the UPS. A higher joule rating indicates better surge protection.


  • LCD Display: Many UPS units feature an LCD that provides real-time data, including battery status, load level, and potential issues.
  • LAN, WiFi, Bluetooth: Advanced UPS models offer connectivity features that allow remote monitoring and management. This can be particularly beneficial for IT administrators managing server rooms or data centers.


A warranty indicates the manufacturer's confidence in the product's durability and performance. When choosing a UPS, it's wise to consider the warranty duration and terms, as this can provide peace of mind and assurance about the product's quality.

A 3-year warranty is a good warranty for computer UPS devices.

Automatic Computer Shutdown

The automatic computer shutdown feature allows the UPS to initiate the shutdown process of connected computers automatically when the remaining battery charge drops to a certain level, for example, 20-30%.

If the computer is connected to UPS via LAN, be sure that network devices are also protected with UPS, or UPS will not be able to communicate with protected computers in the event of power failure.

Home computers are often connected to UPS via a USB control cable, allowing these two units to communicate directly.

Automatic Computer Startup

The automatic computer startup feature allows the UPS to initiate the startup process of connected computers automatically when the remaining battery charge increases to a certain level, for example, 50-60%.

To use this feature, sometimes one needs to change a few power settings/options of the computer in BIOS/UEFI.

UPS For Laptop: Yes Or No?

When considering the use of a UPS (Uninterruptible Power Supply) for a laptop, there are several factors to weigh. At the core, laptops already possess an internal battery, which functions as a built-in UPS of sorts.

However, the decision to use an external UPS is nuanced and can be influenced by the user's specific needs and scenarios.

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Advantages of Using a UPS for a Laptop

  • Data Protection: While a laptop's internal battery provides a power cushion during outages, having a UPS can offer extended protection, especially during prolonged outages. This is especially crucial if you're working on critical tasks and need more time to save data or perform a controlled system shutdown.
  • Protection from Power Surges: Apart from backup power, many UPS units offer surge protection. This protects the laptop and any connected peripherals from potential damage due to sudden voltage spikes.
  • Voltage Regulation: Certain advanced UPS units come with voltage regulation features. This ensures that the power fed to the laptop is consistent and free from harmful fluctuations.
  • Extended Work Duration: In situations where a laptop's internal battery is drained and there's no power, a UPS can provide the necessary backup to continue working or to recharge the laptop's battery to some extent.
  • External Devices: Laptops are often connected to external devices like additional monitors that don't have internal batteries. UPS allows the user to connect the work when mains power is gone and, in the worst-case scenario, to save the work and shut down the laptop.

Note: at the moment, the Author of this article uses a laptop with a graphic card with separate memory and two external 27" monitors - one via built-in HDMI port and the second one via USP-C port extender.

Reasons You Might Not Need a UPS for a Laptop

  • Built-in Battery: The primary function of a UPS is to provide power during outages. Laptops inherently have this capability due to their internal batteries.
  • Portability: If you're always on the move, carrying an additional UPS might not be feasible. It adds extra weight and bulk to your gear. Personally, when I travel, I don't carry my external monitors and UPS.
  • Additional Cost: For those who rarely encounter power outages and already have a reliable laptop battery, investing in a UPS might seem unnecessary.
  • Short-Term Outages: If you're in an area where power outages are brief and infrequent, the laptop's own battery might suffice for those short durations. However, if you use external monitors, in the case of power failure, your computer will switch all your windows to the default screen, making it rather difficult to save the work and shut down your laptop.

The decision to use a UPS for a laptop largely hinges on individual needs. If you're in a region with frequent and prolonged power outages or if you're handling critical data that requires extended protection, a UPS can be invaluable.

However, for casual users or those who primarily rely on their laptop's internal battery, a UPS might not be a priority.

Note: My UPS costs less than 10% of the price of my laptop and a pair of 27" monitors. Personally, that is a good long-term investment.

Few Final Words

computer ups mWhile both UPS and battery backup systems serve to ensure continuity in power delivery, the distinction lies in their response times, advanced features, and intended use.

It's essential to assess the specific needs of your equipment and operational requirements when choosing between the two. As technology continues to evolve, the lines between these devices might blur further, but understanding their foundational differences remains crucial.

In short, if you do need a UPS battery backup for your computer, go for a good UPS unit with enough power, energy, battery-protected AC ports, and monitoring features.