Is 3 minutes enough for entering into safe mode?

[Enquiries]

I have synology DS1520+ with 3 bay installed. I plan to buy a UPS. The power required is about 190W (1.75 x power needed for my devices i.e. NAS, modem and router). It seems that Back-UPS Pro BR550GI is enough for me as it provide 330W output. Yet, it has only 3 minutes to work for full load. I wonder if it is enough for the NAS to run into safe mode in case of power surge. I just need UPS to protect my data in the NAS. Hence longer running times seem not necessary for me. Is Back-UPS Pro BR550GI enough for my need? Thank you very much!

[TribalHound]

Great that you're thinking of power outages before you suffer from one. Most don't appreciate data in NAS often isn't written to the disc, but can linger in the cache for a while.

The Back-UPS Pro BR550GI is rated to a maximum 330w for a little over 3 minutes. However the power brick on the DS1520+ is only rated to a maximum of 120w (that's when the NAS is running at full pelt).

Probability is you will rarely get over 100w consumption, and in idle mode could be using as little as 30-40 w

So playing safe, and assuming your NAS is using 80w when the power trips you'll get a maximum 30 minutes on UPS or at 100w you get a little over 20min.

However, since the NAS effectively goes dormant when the power trips, it'll slowly shut down non essential applications / tasks - meaning it'll be likely using very little within a few minutes, so will extend your time to react and take appropriate action.

Now, the APC uses lead acid batteries, which degrade faster than the modern lithium ones, and shouldn't be discharged as deeply / doesn't have anywhere near the number of discharge cycles. So within a couple of years expect around 80% capacity and base your decision today on that figure.

Therefore the BR550GI 'should' actually give you in excess of 15 minutes for some time to come unless you have other devices plugged into it as well.

As a side note, APC have discontinued the BR550GI, so you might want to look for a newer version with a similar rating for longevity of support & spare parts.

Hope this helps

[TribalHound]

Just to add using your 190w estimate it should run (as new) for a little under 10 minutes.
Dropping that down to 150 (as devices power down) gives you a little over 13 mins.
(Sorry for not reading your question fully).