Adding an UPS power backup to the NAS

Your wallet might be feeling pretty light after splurging on a Network Attached Storage (NAS) with a bunch of new hard drives but you are probably better off in terms of data redundancies. Before you celebrate success, do you know that a dodgy power source can cause a myriad of issues? For example, electronics failure, data corruption. The NAS only has to be writing data when a power outage occurs to corrupt the data. To mitigate the risk of data loss, I got a APC BK650 UPS for my Synology DS1817+ NAS. It is an Uninterruptible Power Supply (UPS).

Tropics = Thunderstorms = Potential (Electrical) Blackout

For those living in the Tropics, we will know that thunderstorms are common occurrences. Although electrical blackouts are rare, it is not an absolute certainty that a blackout won’t happen. If you do not want to take any chances (of losing data on your NAS), you might want just spend a little more on an Uninterruptible Power Supply (UPS).

500VA? 650VA? It’s about endurance

VA is an abbreviation of the term volt-amps. It simply means how much stored energy it can hold. It is just like how USB power banks are rated, a larger number means it can supply more juice to the attached peripherals.

The higher the capacity, the longer the attached peripheral stays on. However, a higher capacity UPS also typically means a bigger physical size.

My rule of thumb is allowing a good five minutes of battery time for the NAS to shutdown safely. For my Synology DS1817+, it has a 250W power supply unit. With the rule of thumb of 70% UPS power factor/ efficiency, a 400VA (250W/70% = approximately 357W) would be sufficient. However, I have intentions of having more peripherals on the UPS so I got a 650VA instead.


A word of caution, the UPS is one heavy equipment at 6kg so be careful when lifting or shifting it around.

On the front panel, you can find the LED status indicators and power button. It gives you an indication of whether the electrical mains are operating well and the health of the battery inside the UPS.

At the back of the UPS are four (4) power outlets – three (3) of them are on uninterruptible power supply; and one (1) only having surge protection. The data port at the top right allows you to connect the UPS to the Synology NAS using a USB data cable. With the connectivity, the Synology NAS can monitor the operating state of the UPS and promptly trigger a safe shutdown in the event of power failure. Hence, do get a UPS that is capable of communicating with the Synology NAS. Do check out Synology compatibility list for UPS.

The battery in the APC BK650 is end-user replaceable. Like all other components, battery experiences wear-and-tear too so having a replaceable battery is great. The battery would probably last three years before needing a change.

Installing and using the UPS

The installation of the UPS is straightforward. It is just a matter of connecting the NAS to the UPS for power and communication using the supplied power and USB cable respectively. Lastly, connect the UPS to the wall socket or mains.

Synology NAS communicating with the APC UPS

After physically connecting up the equipments, the next step is setting up the communication between Synology NAS and APC UPS. In DSM Control Panel > Hardware & Power > UPS, you should see that the UPS is detected and its estimated battery life. You can also set the threshold for it to initiate a shutdown. I set it to shutdown when there is less than five (5) minutes of backup power.

That’s not all. The final step is to do an actual electrical failure test. You can be assured that the setup is working if it passes this final test. To perform this test, power off the mains to test if the UPS swings over to battery and the NAS safely shutting down when it meets the threshold criteria.


Personally, I find the APC BK650 UPS a good addition to my Synology DS1817+. It is compact in size and meets the needs of my overall data protection strategy.

Not all NAS users will splurge on an uninterruptible power supply (UPS) as it is only seen as an additional cost. However, if you have already spent S$2,000 for the NAS setup to protect your precious data, why not go the extra mile to cement your data protection objective?