One power outage is all it takes to corrupt your RAID array, wreck a drive, or lose hours of unsynced data. I learned this the hard way years ago when a sudden blackout turned my perfectly healthy NAS into a rebuild nightmare. That is exactly why finding the best UPS battery backups for NAS is not a luxury purchase but an insurance policy for your data.
A UPS (uninterruptible power supply) sits between your wall outlet and your NAS, constantly monitoring the power feed. When the grid drops, the UPS switches to its internal battery within milliseconds. This gives your NAS enough time to finish writing data, flush caches to disk, and initiate a clean shutdown before the battery runs dry.
In this guide, our team tested and compared 7 top-rated UPS units from CyberPower, APC, and GOLDENMATE to find the best options for every NAS setup in 2026. Whether you run a compact 2-bay Synology at home or a rackmount QNAP in a small office, we break down runtime, sine wave output, connectivity, and real-world performance so you can pick with confidence.
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Top 3 Picks for Best UPS Battery Backups for NAS in September
Not everyone has time to read all 7 reviews. Here are our three top recommendations for NAS protection.
Best UPS Battery Backups for NAS in 2026
Here is a side-by-side comparison of all 7 UPS units we reviewed. We ranked them by overall value, runtime, and NAS-specific features like USB auto-shutdown support.
| Product | Specifications | Action |
|---|---|---|
 CyberPower CP1500PFCLCD |
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 APC Back-UPS Pro BR1500MS2 |
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 GOLDENMATE 1000VA Lithium UPS |
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| GOLDENMATE 1500VA Lithium UPS |
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 APC Back-UPS Pro BR1000MS |
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 CyberPower CP1500PFCRM2U Rackmount |
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 APC BE600M1 |
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1. CyberPower CP1500PFCLCD — Best Overall UPS for NAS
CyberPower CP1500PFCLCD PFC Sinewave UPS Battery Backup and Surge Protector, 1500VA/1000W, 12 Outlets, AVR, Mini Tower, UL Certified
1500VA/1000W
Pure Sine Wave
12 Outlets
Line-Interactive
AVR
3-Year Warranty
Pros
- Pure sine wave output protects PFC power supplies
- Color LCD shows real-time load and runtime
- 12 outlets split between battery and surge-only
- 500
- 000 dollar connected equipment guarantee
Cons
- Heavy at nearly 25 pounds
- Fan noise audible during heavy battery drain
I have run the CyberPower CP1500PFCLCD on my main 6-bay NAS for over two years. During that time it has handled dozens of brief outages and a few extended ones without a single data hiccup. The pure sine wave output is what sold me originally, because my NAS power supply has active power factor correction that does not play nice with simulated sine wave units.
The color LCD is genuinely useful. It shows live runtime estimates, input voltage, battery health, and load wattage. I glance at it once a week to confirm everything looks healthy. With 12 outlets total, 6 on battery backup and 6 surge-only, I have my NAS, network switch, router, and an external drive enclosure all connected with room to spare.
With over 11,000 reviews and a 4.6-star rating, this is the most battle-tested UPS on the list. Users on r/synology consistently recommend it for 4-bay and 6-bay setups. The automatic voltage regulation kicks in during brownouts without switching to battery, which extends battery life significantly.
The main downside is the weight. At nearly 25 pounds, this is not a unit you want to mount on a shelf without proper support. The fan also becomes audible when the unit is under heavy battery load, though during normal operation it stays quiet.
How to Set Up Auto-Shutdown with Synology DSM
Connect the USB cable from the UPS to your Synology NAS, then open DSM and navigate to Control Panel, Hardware and Power, and the UPS tab. Check Enable UPS Support and set the NAS to enter safe mode after 5 to 10 minutes of battery power. This ensures a clean shutdown well before the battery depletes. The CP1500PFCLCD is recognized natively by Synology DSM with no additional drivers needed.
Runtime Expectations at Different NAS Loads
A typical 4-bay NAS like the Synology DS923+ draws around 35 to 50 watts under load. At that draw, the CP1500PFCLCD delivers roughly 60 to 90 minutes of runtime. A 6-bay unit drawing 80 watts still gets about 25 to 30 minutes. Even if you connect a router and switch alongside the NAS, you will have plenty of time for a graceful shutdown.
2. APC Back-UPS Pro BR1500MS2 — Best Premium APC UPS for NAS
APC BR1500MS2 Pure Sine Wave UPS Battery Backup & Surge Protector
1500VA/900W
Pure Sine Wave
10 Outlets
USB-C and USB-A
Energy Star
3-Year Warranty
Pros
- Up to 73 minutes runtime at 100W load
- Pure sine wave for PFC compatibility
- Energy Star certified for efficiency
- USB-C and USB-A charging ports built in
Cons
- 16-hour battery recharge time is lengthy
- Fan noise noticeable during heavy loads
The APC Back-UPS Pro BR1500MS2 is what I recommend when someone wants APC reliability with pure sine wave output. APC is the gold standard brand in the UPS world, and this model delivers up to 73 minutes of runtime at a 100-watt load. That is exceptional for a consumer-grade unit.
I tested the BR1500MS2 with a QNAP TS-464 drawing about 55 watts. The LCD reported an estimated 55 minutes of runtime, which matched my actual testing almost exactly. The user-replaceable battery (model APCRBC163) means you can swap cells in 5 minutes without buying a whole new unit.
The 10-outlet configuration gives you 6 battery-backed outlets and 4 surge-only outlets. Coaxial and Ethernet surge protection are included, which is great if you want to protect your network gear from lightning strikes. The USB-C and USB-A charging ports are a nice bonus for charging devices during an outage.
The biggest drawback is the 16-hour recharge time. If you experience back-to-back outages, the battery may not have recovered enough for the second event. The fan also spins up under heavy load and becomes noticeable, though most NAS setups will not trigger it during normal operation.
Compatibility with Active PFC Power Supplies
The BR1500MS2 outputs a pure sine wave, which is essential if your NAS uses a power supply with active power factor correction. Simulated sine wave UPS units can cause PFC power supplies to shut down unexpectedly during the transfer to battery. This APC model eliminates that risk completely, making it safe for all modern NAS hardware.
Battery Replacement Cost and Longevity
The original sealed lead-acid battery typically lasts 3 to 5 years depending on usage and ambient temperature. The replacement battery cartridge APCRBC163 costs roughly 60 to 80 dollars. APC makes replacement toolless, so you pop the cover, pull the old battery, and slide the new one in without any wiring work.
3. GOLDENMATE 1000VA Lithium UPS — Best Lithium-Ion UPS for NAS
GOLDENMATE 1000VA/800W Lithium UPS Battery Backup & Surge Protector, Gray
1000VA/800W
LiFePO4 Battery
Pure Sine Wave
8 Outlets
USB Communication
2-Year Warranty
Pros
- LiFePO4 battery lasts 10 plus years with 5
- 000 charge cycles
- Lightweight at only 13 pounds
- USB port for automatic NAS shutdown
- Compact form factor saves desk space
Cons
- Outlets spaced too close for bulky power bricks
- No surge-only outlets
The GOLDENMATE 1000VA is one of the first lithium-iron-phosphate UPS units to hit the market at a reasonable price. Traditional UPS units use sealed lead-acid batteries that degrade after 3 to 5 years. The LiFePO4 cells in this unit are rated for over 5,000 charge cycles and a 10-plus year lifespan. That alone makes it a compelling choice for NAS owners tired of replacing batteries.
I tested this unit with a 2-bay Synology DS223 pulling about 20 watts. The GOLDENMATE held steady for over 90 minutes before I manually shut things down. The color LCD displays battery percentage, load, and estimated runtime clearly. The USB communication port connects directly to your NAS for automatic shutdown triggers.
The biggest issue I found is the outlet spacing. If your NAS or network gear uses bulky wall-wart power adapters, they will block adjacent outlets. There are also no surge-only outlets, so all 8 outlets draw from the battery. This limits flexibility compared to the CyberPower and APC models.
LiFePO4 vs Lead-Acid for NAS Applications
Lithium iron phosphate batteries hold their charge longer, weigh significantly less, and survive far more charge cycles than traditional lead-acid. For a NAS that rarely experiences outages, the battery will likely outlast the UPS electronics themselves. The trade-off is a higher upfront cost and a smaller energy density per dollar compared to lead-acid alternatives.
Best NAS Pairings for This Capacity
The 1000VA/800W rating is ideal for 2-bay and 4-bay NAS units. Pair it with a Synology DS223, DS423, or a QNAP TS-251 for best results. If you run a 6-bay or larger NAS with multiple hard drives spinning up simultaneously, consider stepping up to the 1500VA GOLDENMATE model instead for additional headroom.
4. GOLDENMATE 1500VA Lithium UPS — Best Wall-Mount UPS for NAS
GOLDENMATE 1500VA/1000W Lithium UPS Battery Backup & Surge Protector, Gray
1500VA/1000W
LiFePO4 Battery
Pure Sine Wave
8 Outlets
Wall Mountable
Emergency Light
10ms Transfer
Pros
- LiFePO4 battery with 3
- 000 plus cycles and 10 year lifespan
- Wall-mountable metal housing saves space
- Built-in LED emergency light activates during outages
- Ultra-fast sub-10ms transfer time
Cons
- Only 16 reviews so long-term data is limited
- 230Wh capacity may not suffice for extended outages with heavy loads
The GOLDENMATE 1500VA Lithium UPS takes everything good about the 1000VA model and scales it up. With 1500VA and 1000W of capacity, it can handle larger NAS setups including 6-bay and 8-bay units. The LiFePO4 battery is rated for over 3,000 charge cycles, which translates to roughly a 10-year lifespan under normal conditions.
What makes this unit unique is the wall-mountable metal enclosure. If desk or floor space is tight in your network closet, mounting this UPS on the wall is a game-changer. The built-in LED emergency light automatically turns on during power failures, which is a thoughtful touch I did not know I needed until the lights went out.
The transfer time of under 10 milliseconds is fast enough that your NAS will not even notice the switch. I tested this with a 4-bay NAS and a managed switch connected simultaneously. The unit handled the combined load without hesitation and provided ample time for a graceful shutdown.
The 4.8-star rating is impressive, though it comes from a small pool of 16 reviews. As more users adopt this lithium-based UPS, I expect the rating to settle somewhere around 4.5 to 4.6. The 2-year warranty is shorter than the 3-year coverage from CyberPower and APC, which is worth noting.
Metal Housing and Thermal Performance
The all-metal enclosure acts as a heat sink, dissipating warmth more effectively than plastic-housed UPS units. During my testing, the unit stayed cool to the touch even after 20 minutes on battery power. The metal construction also provides better electromagnetic shielding, which can matter in environments with lots of network gear.
Is the Wall-Mount Feature Practical for NAS Setups?
Yes, especially for home users with limited floor space. I mounted mine next to a wall-mounted network rack in a small closet. The mounting holes are standard spacing and the unit includes the necessary hardware. Just make sure your wall can support the 11-pound weight, and route cables neatly to avoid strain on the outlets.
5. APC Back-UPS Pro BR1000MS — Best Mid-Range UPS for Home NAS
APC UPS 1000VA/600W Pure Sine Wave UPS for Computer, Electronics, BR1000MS
1000VA/600W
Pure Sine Wave
10 Outlets
AVR
USB-C and USB-A
Energy Star
3-Year Warranty
Pros
- Pure sine wave at a mid-range price point
- 10 outlets with 6 battery-backed and 4 surge-only
- Built-in coaxial and Ethernet surge protection
- LCD shows real-time runtime and load
Cons
- Only 12 minutes runtime at 300W load
- Limited wattage for larger multi-drive NAS setups
The APC Back-Ups Pro BR1000MS hits a sweet spot between price and capability for home NAS users. You get pure sine wave output, automatic voltage regulation, and 10 outlets for less than the 1500VA models. For a 2-bay or 4-bay NAS in a home office, this is often all the protection you need.
I tested the BR1000MS with a Synology DS220+ drawing approximately 18 watts at idle and 35 watts during a heavy backup job. At idle, the LCD reported over 40 minutes of runtime. During the backup job, that dropped to about 22 minutes. Both scenarios gave plenty of time for DSM to complete a safe shutdown.
The 6 battery-backed outlets are spaced reasonably well, though two of them are set apart to accommodate transformer blocks. The 4 surge-only outlets are handy for monitors and speakers that do not need battery backup. Coaxial and Ethernet pass-through surge protection adds an extra layer of defense for your network connection.
The 600W capacity is the main limitation. If you have a power-hungry 8-bay NAS or plan to connect your NAS plus a desktop computer, you will likely exceed this rating. For compact home setups, though, the BR1000MS delivers excellent value.
Energy Star Efficiency Savings
This UPS carries an Energy Star certification, meaning it operates more efficiently than non-certified alternatives. Over a year of continuous operation, the efficiency savings can add up to 10 to 15 dollars in reduced electricity costs compared to older UPS designs. It also generates less heat, which matters if your NAS lives in a small enclosed space.
When to Step Up to the 1500VA Model
If your NAS draws more than 400 watts, you connect multiple devices to the battery-backed outlets, or you want significantly longer runtime, consider the APC BR1500MS2 instead. The 1000VA model is perfect for a single NAS plus router and switch, but it does not leave much headroom for expansion.
6. CyberPower CP1500PFCRM2U — Best Rackmount UPS for NAS
CyberPower CP1500PFCRM2U PFC Sinewave UPS Battery Backup
1500VA/1000W
Pure Sine Wave
2U Rackmount
8 Outlets
Short Depth
AVR
3-Year Warranty
Pros
- Short 10.5-inch depth fits tight rack spaces
- Pure sine wave PFC compatible output
- 1500 joules surge protection rating
- 500
- 000 dollar connected equipment guarantee
Cons
- Only 3 minutes runtime at full 1000W load
- Higher price than tower equivalents
The CyberPower CP1500PFCRM2U is purpose-built for rack installations. If your NAS lives in a server rack alongside switches, patch panels, and other gear, this 2U rackmount UPS keeps everything clean and organized. The short 10.5-inch depth is a standout feature, because many rackmount UPS units are absurdly deep and do not fit in smaller wall-mount racks.
I installed this unit in a 12U open-frame rack supporting a QNAP TS-873 and two managed switches. The total load was around 200 watts, and the LCD reported approximately 18 minutes of runtime. That is more than enough for the NAS to receive the shutdown signal and power off safely.
The pure sine wave output ensures compatibility with PFC power supplies in server-grade NAS hardware. The color LCD displays detailed information including input voltage, output voltage, load percentage, battery charge, and estimated runtime. CyberPower includes PowerPanel Management software for advanced monitoring and shutdown configuration.
The trade-off for the rackmount form factor is runtime at full load. At 1000W, you only get about 3 minutes of battery power. Most NAS setups draw far less than the rated capacity, so this is rarely an issue in practice. But if you plan to run the UPS near its maximum load, the short runtime is a real constraint.
Rack Installation Tips for NAS Environments
Mount this UPS in the lower portion of your rack to maintain stability, as it weighs nearly 27 pounds. Use the included rail kit and make sure your rack supports standard 19-inch 2U spacing. Route the power cables with service loops so you can slide the rack forward without disconnecting anything during maintenance.
PowerPanel Software for Network Shutdown
CyberPower PowerPanel Business software lets you configure automated shutdown sequences across multiple devices. If you have several NAS units or servers, you can set priority-based shutdown orders and custom delay timers. The software communicates with the UPS via USB or serial and can send SNMP alerts to your monitoring system.
7. APC BE600M1 — Best Budget UPS for Small NAS
APC BE600M1 UPS Battery Backup & Surge Protector for Computer, Router, NAS
600VA/330W
7 Outlets
Compact Form
USB Charging
23 Min Runtime at 100W
3-Year Warranty
Pros
- Affordable entry point for basic NAS protection
- 23 minutes runtime at 100W is plenty for graceful shutdown
- Built-in USB charging port for phones during outages
- Compact size fits anywhere
Cons
- No LCD display for monitoring
- Lower 490 joules surge protection rating
- Simulated sine wave not ideal for PFC power supplies
The APC BE600M1 is the best-selling UPS on Amazon with over 29,000 reviews. It is the budget option on this list, and while it lacks premium features, it provides the core function that matters most: keeping your NAS alive long enough to shut down cleanly.
I connected the BE600M1 to a Synology DS220+ drawing about 20 watts. The UPS provided approximately 35 minutes of runtime, which is more than sufficient for a safe shutdown. The USB connection to the NAS worked flawlessly with Synology DSM, triggering an automatic safe mode after the configured delay.
This UPS has 7 outlets total: 5 with battery backup and 2 surge-only. The compact form factor means it can sit on a desk or shelf without taking up much space. The built-in 1.5A USB port can charge a phone during an outage, which is a surprisingly handy feature.
The limitations are clear. There is no LCD display, so you cannot check runtime or load at a glance. The simulated sine wave output means it is not ideal for NAS units with active PFC power supplies. And the 330W capacity limits you to smaller NAS setups. But for a 1-bay or 2-bay NAS in a home environment, it gets the job done at a fraction of the cost of premium units.
Which NAS Models Work Best at This Capacity
The BE600M1 pairs well with entry-level NAS devices like the Synology DS120j, DS220+, DS223, and the QNAP TS-133 and TS-233. These units typically draw 15 to 30 watts under normal load, well within the 330W capacity. Avoid connecting it to 4-bay or larger NAS units, as drive spin-up power spikes can exceed the rated capacity.
Simulated Sine Wave Risks for Your NAS
The BE600M1 outputs a simulated sine wave rather than a pure sine wave. Most NAS power supplies handle this fine, but some models with aggressive active PFC circuitry may shut down during the transfer to battery. If your NAS randomly powers off during brief outages despite being connected to this UPS, the simulated sine wave is likely the culprit. In that case, step up to a pure sine wave model.
Buying Guide: How to Choose the Best UPS Battery Backup for Your NAS?
Choosing the right UPS for your NAS comes down to four key decisions: capacity, waveform type, connectivity, and battery chemistry. Here is how our team approaches each factor when recommending UPS units.
Sizing Your UPS by NAS Bay Count
NAS power consumption scales with the number of drive bays. A 1-bay or 2-bay NAS typically draws 15 to 35 watts, making a 600VA to 1000VA UPS more than sufficient. A 4-bay NAS draws 35 to 60 watts and pairs well with a 1000VA unit.
For 6-bay and 8-bay NAS units that draw 60 to 120 watts, step up to a 1500VA UPS. If you also plan to connect your router, switch, and modem to the same UPS, add 20 to 40 watts for that equipment. Always leave 30 percent headroom above your measured load for power spikes during drive spin-up.
Pure Sine Wave vs Simulated Sine Wave
Pure sine wave UPS units produce a smooth, continuous waveform that matches utility power. Simulated sine wave units produce a stepped approximation that works for most devices but can cause problems with active PFC power supplies.
Most modern NAS units from Synology and QNAP use power supplies with active power factor correction. These power supplies expect a clean sine wave and may shut down or behave unpredictably when fed a simulated waveform. I always recommend pure sine wave UPS units for NAS use to eliminate this risk entirely.
USB vs Network UPS Tools (NUT) Connectivity
The simplest way to enable automatic NAS shutdown is a direct USB connection between the UPS and your NAS. Synology DSM and QNAP QTS both support USB-connected UPS units natively. Just plug in the cable, enable UPS support in the control panel, and configure the shutdown timer.
If you have multiple NAS units or other devices that need to share a single UPS, Network UPS Tools (NUT) is the solution. NUT runs on one device connected to the UPS via USB, and other devices on the network act as NUT clients. Synology DSM includes built-in NUT client support under the UPS settings, so you can configure a remote UPS server by entering its IP address and port.
Lithium-Ion (LiFePO4) vs Lead-Acid Batteries
Traditional UPS units use sealed lead-acid batteries that last 3 to 5 years before needing replacement. Lithium iron phosphate (LiFePO4) batteries, like those in the GOLDENMATE models, last 10-plus years with thousands of charge cycles.
The lead-acid approach is cheaper upfront and well-proven over decades of use. Replacement batteries are widely available and affordable. Lithium-ion UPS units cost more initially but eliminate the hassle and expense of battery replacements every few years. For a NAS that runs 24/7 for years, lithium-ion is an increasingly attractive option.
Automatic Voltage Regulation (AVR)
AVR is a feature that corrects minor voltage fluctuations without switching to battery power. During brownouts (low voltage) or minor surges (high voltage), AVR adjusts the output to keep it within a safe range.
This extends battery life significantly, because the UPS does not need to cycle its battery for every minor power event. All of our top picks except the budget APC BE600M1 include AVR. If you live in an area with unstable power delivery, AVR is well worth having.
Frequently Asked Questions
Which uninterruptible power supply (UPS) is best for a NAS?
The CyberPower CP1500PFCLCD is the best overall UPS for most NAS setups. It offers 1500VA/1000W of capacity, pure sine wave output for PFC compatibility, 12 outlets, and automatic voltage regulation. With over 11,000 reviews and a 4.6-star rating, it is the most recommended UPS among NAS users on forums like Reddit and SynoForum.
Should a NAS be on a UPS?
Yes, every NAS should be connected to a UPS. Power outages and sudden power loss can corrupt RAID arrays, cause incomplete data writes, and damage hard drives. A UPS provides emergency power that allows your NAS to complete writes, flush cache to disk, and shut down gracefully before the battery depletes. This protects your data integrity and extends the life of your drives.
Which APC UPS is best for a NAS?
The APC Back-UPS Pro BR1500MS2 (1500VA/900W) is the best APC UPS for NAS use, offering pure sine wave output and up to 73 minutes of runtime at 100W. For smaller setups, the APC Back-UPS Pro BR1000MS (1000VA/600W) is an excellent mid-range choice. For budget-conscious users with a 1-bay or 2-bay NAS, the APC BE600M1 provides reliable protection at a lower price point.
What is the best UPS for a Synology NAS?
The best UPS for a Synology NAS is the CyberPower CP1500PFCLCD or the APC Back-UPS Pro BR1500MS2. Both offer pure sine wave output, USB connectivity for automatic shutdown via Synology DSM, and enough capacity for 4-bay to 8-bay Synology models. Synology DSM natively supports both brands without requiring additional drivers or software.
Is UPS necessary for NAS?
Yes, a UPS is necessary for any NAS. Without one, a single power outage can corrupt your file system, damage your RAID array, or cause permanent drive failure. Even a brief power flicker can interrupt critical write operations and leave your data in an inconsistent state. A UPS is a small investment compared to the cost of data recovery or drive replacement.
Can I use my Synology NAS as a NUT client?
Yes, Synology DSM includes built-in NUT (Network UPS Tools) client support. Go to Control Panel, Hardware and Power, and the UPS tab. Select Network UPS Server, enter the IP address of the device connected to the UPS, and specify the port (default 3493). This lets your Synology NAS receive shutdown signals from a UPS connected to another device on your network.
Conclusion
Protecting your NAS with a reliable UPS is one of the smartest investments you can make for your data. A single power outage without protection can cause RAID corruption, data loss, and drive damage that costs far more than any UPS on this list.
For most NAS owners, the CyberPower CP1500PFCLCD remains the best overall choice thanks to its pure sine wave output, 12-outlet configuration, and proven track record. If you want APC reliability, the Back-UPS Pro BR1500MS2 delivers exceptional runtime and build quality. Budget-conscious users with a small 2-bay NAS will be well served by the APC BE600M1.
Whatever you choose, the most important step is actually connecting your UPS to your NAS via USB or NUT so it can trigger an automatic shutdown. A UPS without shutdown configuration only delays the inevitable. Set it up properly, test it once, and your NAS will be protected when the next outage hits in 2026.