Search  for anything...
CyberPower

CyberPower ST425 Standby UPS Battery Backup and Surge Protector

Based on 5,461 reviews
Condition: New
Checking for the best price...
$59.95
Holiday Deal · 8% off was $64.95

Buy Now, Pay Later

As low as $9.99 / mo
  • – 6-month term
  • – No impact on credit to apply
  • – Instant approval decision
  • – Secure and straightforward checkout

Ready to go? Add this product to your cart and select a plan during checkout.

Payment plans are offered through our trusted finance partners Klarna, Affirm, Afterpay, Zip, Apple Pay, and Google Pay. No-credit-needed leasing options through Acima may also be available at checkout.

Learn more about financing & leasing here.

Selected Option

Free shipping on this product
This item's return window has been extended for the holiday season: FREE refund/replacement until Jan 31, 2027

To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

Availability: In Stock.
Fulfilled by Amazon
Arrives Wednesday, Nov 11
Order within 4 hours and 53 minutes

Available payment plans shown during checkout

Protect Your Purchase

Easy claims online, fast replacements, no fees

Checking for protection plans...

Recently Viewed

At a glance

Condition
New
Style
Compact
Size
425VA
Model
ST425
Dimensions
3.2 x 8.3 x 4.5 in
Weight
3.8 lb
Color
Black
Warranty
3-YEAR WARRANTY – INCLUDING THE BATTERY, $75,000 Connected Equipment Guarantee

Features 5

  • 425VA/260W Standby Uninterruptible Power Supply (UPS): Uses simulated sine wave output to provide battery backup power and to safeguard home office, home entertainment including computers, gaming consoles, and broadband routers
  • 8 NEMA 5-15R OUTLETS: Four battery backup & surge protected outlets; Four surge protected outlets; INPUT: NEMA 5-15P right angle, 45 degree offset plug with five foot power cord
  • ADDITIONAL FEATURES: LED status light indicates Power-On and Wiring Fault, transformer-spaced outlets
  • GREENPOWER UPS HIGH EFFICIENCY DESIGN: Reduces power consumption by utilizing a compact charger and power inverter to create an ultra-efficient backup power system for home and office use

Description

The CyberPower ST425 Uninterruptible power supply (UPS) system provides battery backup and surge protection for lightning-induced surges and other power events that can damage electronic equipment. This unit delivers enough battery backup to power connected electronics through utility power failure and enough runtime to perform a graceful shutdown to protect against the loss of data and damage to valuable electronics during longer outages. Including a sleek design, this UPS is perfect for all your home office and entertainment needs, including computers, gaming consoles, and Broadband routers. With a 75K USD lifetime connected equipment guarantee and a three-year warranty, you can trust CyberPower commitment to the quality of this battery backup with surge protection.

Specs 39

Brand CyberPower
Battery Cell Composition Lead Acid
Product Dimensions 3.2"D x 8.3"W x 4.5"H
Voltage 120 volts
Color Black
Amperage 2.17 A
Battery Charge Time 76 A
Form Factor Compact

Frequently asked questions

The CyberPower ST425 UPS can provide backup power during outages, but the exact duration depends on the total power load of the connected devices. For a setup with a moderate load like a single PC and monitor, it typically offers around 8-10 minutes of runtime, allowing you to save your work and shut down safely. For lower loads, the runtime increases.

No, the CyberPower ST425 Standby UPS System is not suitable for high-power appliances like refrigerators, space heaters, or air conditioners. It's designed for low-power devices such as computers, networking equipment, and entertainment systems. Its maximum capacity is 425VA/260W, which is not sufficient for high-power appliances.

The CyberPower ST425 Standby UPS System is designed for easy use without the need for special software for basic functionality. However, for advanced features such as power management and scheduled shutdowns, CyberPower offers a free downloadable software called PowerPanel Personal which is compatible with Windows systems. This software can provide valuable insights into power usage and battery health.

The CyberPower ST425 requires minimal maintenance. It's important to check the battery status regularly and ensure the unit is kept in a dry, ventilated area to prevent overheating. The battery typically needs replacement every 3-5 years, depending on usage and environment. CyberPower provides instructions for safe battery replacement, and it's a process that users can often do by themselves.

Similar Products

Top Amazon Reviews

🚀 Abunda's Overview

This is our summary and key points to consider based on customer reviews.

The CyberPower 425 VA UPS secures critical acclaim across varied reviews for its dependable and efficient power protection, appealing to a broad user base with diverse device support needs. Its compact size, straightforward setup, and quiet operation underline its suitability for both home and small office environments. Moreover, its ability to manage power interruptions gracefully, offering substantial uptime for devices during outages, contributes to its strong recommendation among users.

Pros

  • 🔌 Efficient and reliable power protection for a wide range of devices.
  • 🔇 Quiet operation, even under load or while charging.
  • 👍 Compact design with a simple setup process.
  • 💡 Adequate power backup time, with about 90 minutes for light loads and around 10 minutes for heavier loads.
  • 🌐 Offers both surge protection and battery backup across multiple outlets.

Cons

  • 🔋 High replacement cost for the battery, which may deter users from sustaining the product long term.
  • 🎚 The audible alert (beep) for power disconnection can be loud and may be intrusive for some settings.
  • 🧰 Modifications for extended battery life require technical skills, limiting accessibility for the average user.

Should I Buy It?

If you're in need of a reliable, compact UPS that can protect a variety of devices from power interruptions without causing a racket, the CyberPower 425 VA UPS is an excellent choice. Particularly suited for those with lower power requirements or those looking to provide backup for essential devices, its merits far outweigh its demerits. However, be mindful of the potentially high battery replacement cost. Overall, if the specs align with your needs, it comes highly recommended.

Perfect for Keeping Internet Running During Outages
Style: Compact Size: 425VA
This has worked exactly as we hoped. We bought it to keep our internet running during power outages, and it recently proved itself during a brief power outage. The battery backup kicked in immediately, and our modem and router stayed powered without any interruption. It was easy to set up, has a compact design, and gives us great peace of mind knowing we won’t lose our internet every time the power flickers. If you’re looking for an affordable, reliable battery backup for your home network, I highly recommend the CyberPower ST425. ... show more
Reviewed in the United States on July 24, 2026 by Chelsea
Not a long battery, but if you have generator automatic bridges, the gap
Style: Compact Size: 425VA
These are great if you have a standby generator just enough time for it to turn on and not risk any of your electronics
Reviewed in the United States on September 27, 2026 by J. Watt
Good unit
Style: Compact Size: 425VA
I bought this to replace the exact same unit, it saved my computer during a terrible lightning storm where we repeatedly lost and regained power. I assume it burned out but it saved the computer and router and printer That were hooked up to it.
Reviewed in the United States on September 24, 2026 by Karl Bocchieri
Pay attention to the UPS outlets you are using
Style: Compact Size: 425VA
I bought this UPS to protect and power a few small devices that the house sorta depends on, my router, a phone signal amplifier and a Raspberry PI that runs some home automation software. The power load is not high, it doesn't have to run for long before the house generator starts up, and I needed it to be small so it is not obvious where it is located so this fits the situation and need. It had been installed for about a week and a thunderstorm took out the power for all of about 15 seconds and every thing that was plugged into it shut down. I remembered reading in other reviews that people had issues where this UPS did not keep the items plugged into it working and thought I was another one of these lucky people and was all set to crank out a negative review and return it. Then it dawned on me that this UPS, like many others, has two sets of outlets. One set both surge protect and powers devices during power loss and the other set just offers surge protection. Could I have plugged my devices into the surge suppression only outlets? I unplugged the UPS and sure enough, everything plugged into it shut down but the power light on the UPS remained lit. With the UPS still unplugged, I moved the power from the side it was plugged into to the other side and the router began powering up again so it was my error by plugging into the wrong outlets on the UPS. This is the reason for the title of this review and a warning to others using or purchasing this UPS. If the UPS doesn't seem to work, make sure you are plugged into the correct outlets of the UPS before writing it off as dead or defective. Sure, you could be simply overloading it but in those cases, it normally would run for a few seconds and sound a different alarm when that happens. The reason I gave it 4 instead of 5 stars is because it seems to run a bit on the warm side. Not hot enough to burn your fingers but hot enough to feel it getting warm. That just might be due to its small size and only time will tell if that's normal but otherwise, it seems to be well suited for my needs. ... show more
Reviewed in the United States on July 20, 2026 by T. Bonini
Reliable Backup in a Compact Package
Style: Compact Size: 425VA
This UPS backup unit is compact, easy to set up, and provides plenty of outlets for my computer, monitor, and other essentials. It gives me peace of mind during power flickers and short outages, while the battery backup and surge protection work as expected. The design is simple, quiet, and convenient for a home office. It fits neatly under my desk without taking up much space, and the 425VA capacity is a great match for basic electronics. A dependable and affordable backup solution. ... show more
Reviewed in the United States on October 6, 2026 by JustinTime
Perfect for keeping the Internet on
Style: Compact Size: 425VA
Wanted this to keep my router and modem on during power outages and worked great! My TV however still shut off, but I think it's due to it being cheap and doesn't have a good power supply. However my main concern was my internet staying on. I've seen some reviews about people using this for a PC and it not working. Well, this shouldn't be used for that, you need a more powerful UPS. This item is great for smaller things such as a router or a modem, maybe a small fan. I definitely recommend this! ... show more
Reviewed in the United States on July 15, 2026 by Anjelica
0% success rate on all three I purchased. buyer beware.
Style: Compact Size: 425VA
I've purchased three of these now, and none of them support even the tiniest load for even a second when the power goes out. I moved into a new old house about a year ago and set up a bunch of electronics. After much research and reading reviews I decided since I need three of these in different parts of the house, I'd get the load needed with a little buffer room to save money. The one in the south end of the house runs nothing but a 1w radio and a 30w fan. The one in my tech closet runs half a dozen small electronics and my home assistant pc. The one in my office should run my home pc, monitors and a few small electronics on a shelf. None more than half the 425 load these should be able to carry. The electricity here hasn't gone out permanently in the year since I moved in, but it has flashed off for more than a minute a few dozen times. First time I used the first unit, it didn't work. Power flashed off and the pc instantly shut down, alarm sounding on the UPS. I took out the battery to make sure it's connected and charged up, all looks great. Next time the power flashed, everything died again. By this point I'd already ordered two more, so now everything in my house that I need to stay running, only for a minute or two, shuts off even when properly plugged into the battery backup side of the ups. Frustrating. These are the cheaper option, but it's still a lot of money for three things probably out of the return window now, that haven't worked once since day one. Spend the money on the better brand, buy once cry once. Now I have to do that too, but I've already wasted the money on these too so cry twice I guess. ... show more
Reviewed in the United States on March 8, 2026 by GR
Battery back up
Style: Compact Size: 425VA
This was purchased for our office and working great. It’s proven itself worth a few times already and we were thankful!
Reviewed in the United States on September 17, 2026 by marina
How it works
Checking for best price...