---
product_id: 453272874
title: "Eaton Serie 3S UPS 3S550B – 550VA 330W Off‑Line Backup Power, Quiet Fan‑less Design, 6× UK BS Outlets with Battery & Surge Protection, USB HID Interface, Black & White (B0B3RS2986)"
brand: "eaton"
price: "€ 281.81"
currency: EUR
in_stock: true
reviews_count: 6
category: "Eaton"
url: https://www.desertcart.fi/products/453272874-eaton-serie-3s-ups-3s550b-550va-330w-off-line-backup
store_origin: FI
region: Finland
---

# 10 min standard runtime 550 VA / 330 W power capacity 6 BS outlets (3 battery + 3 surge) Eaton Serie 3S UPS 3S550B – 550VA 330W Off‑Line Backup Power, Quiet Fan‑less Design, 6× UK BS Outlets with Battery & Surge Protection, USB HID Interface, Black & White (B0B3RS2986)

**Brand:** eaton
**Price:** € 281.81
**Availability:** ✅ In Stock

## Summary

> ⚡ Power through outages like a pro—never miss a beat with Eaton 3S 550 BS!

## Quick Answers

- **What is this?** Eaton Serie 3S UPS 3S550B – 550VA 330W Off‑Line Backup Power, Quiet Fan‑less Design, 6× UK BS Outlets with Battery & Surge Protection, USB HID Interface, Black & White (B0B3RS2986) by eaton
- **How much does it cost?** € 281.81 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.fi](https://www.desertcart.fi/products/453272874-eaton-serie-3s-ups-3s550b-550va-330w-off-line-backup)

## Best For

- eaton enthusiasts

## Why This Product

- Trusted eaton brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Extended Runtime:** Up to 10 minutes of backup power—enough to save work and gracefully shut down.
- • **Reliable Power Shield:** Seamlessly protects your PC, router & gaming gear from outages and voltage spikes.
- • **Smart USB Integration:** Plug & play USB port for instant OS compatibility and real-time UPS status alerts.
- • **Versatile Outlet Design:** 6 outlets with separated battery backup and surge-only zones for flexible device protection.
- • **Built to Last & Easy to Maintain:** Slide-out battery panel for quick swaps and durable build ensures long-term peace of mind.

## Overview

The Eaton 3S 550 BS UPS delivers 550 VA / 330 W of reliable backup power with a 10-minute runtime, safeguarding your essential electronics from power interruptions and surges. Featuring 6 BS outlets split between battery backup and surge protection, plus a USB port for seamless OS integration, it’s designed for professionals who demand uninterrupted productivity and easy maintenance with its slide-out battery panel and robust build.

## Description

Buy

Review: Takes mains outages in its stride - I bought this UPS a couple of months ago because the mains was becoming unstable with the lights flickering badly etc. (later traced by the utility company to a poor connection out in the street). Two days after I installed it and connected my PC, Router and Smart TV, the mains went unreliable with more flickering lights and clocks resetting etc., but the connected router and PC just continued working as normal. There have been a couple of momentary mains outages of a few seconds since and again the PC etc. had no problems. I also discovered on the Eaton website there's a form to fill in for the monitor software, I put something like private domestic user and was sent a link to a slightly older but perfectly functional and useful piece of software to monitor the current status and alarms. The distance between the two rows of sockets for filtered and filtered+UPS is larger than on some other UPS units which means some bulkier adaptor type plugs rather than the normal plug size can be accommodated. It also has a slide out panel on the base giving access to the battery which means it can easily be swapped out when at the end of its serviceable life. This makes me think this is a unit built to last. I am very pleased with my purchase which is performing flawlessly and wouldn't want to be without it.
Review: Brilliant and saved my RAID drive a couple of times.... - A great looking and compact UPS and easy to mount. I've used the mounting holes that's meant for walls and reinforced it with a couple of heavy duty straps under my height adjustable table, because I didn't want a number of un-sightly cables risk getting caught as I raise my desk. On one side of the strip is surge protection and the other uses the UPS, I didn't know this at first as I skipped the instructions and was wondering why it wasn't working! I got this was for my NVMe RAID which is very sensitive when power is suddenly cut and I risk a 2 day rebuild/re-install, I've already had it come on twice when the lights started flickering and thank goodness I had this. It comes with a long USB cable for communication and my Mac already has a fantastic built-in feature that brings-up a message in the middle of the screen, warning you're now running on UPS battery and to save/back-up etc. there's also a battery level indicator on the desktop strip. I'm running a power-hungry 40inch curved LG monitor, a RAID SSD and NVMe RAID, Macbook M1 Max, various SSD HD, a Thunder Bolt 4 hub and a Wifi6e router - when the power goes, there is a low level alarm and I get around 7 minutes to save and power down, which is more than enough, but luckily we only get very short power outage in London. Highly recommended and everyone should get one to protect their IT equipment.

## Features

- Battery backup during power outages and unsafe voltage fluctuations, as well as protection from damaging surges and spikes - Ideal for the protection of: desktop computers, wireless networks, internet routers, printers, gaming consoles and other electronics
- Power: 550 VA / 330 Watts - Standard runtime: 10 minutes
- Power supply with 6 total BS outlets: 3 battery backup + 3 surge onlyUSB port (HID-compliant) for automatic integration with most common operating systems
- Delivery Contains: 6 BS outlets UPS + 2 IEC output cords (1.5m) + Quick start + safety instructions
- 2 years standard warranty

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0B3RS2986 |
| Best Sellers Rank | 7,530 in Computers & Accessories ( See Top 100 in Computers & Accessories ) 8 in Computer Uninterruptible Power Supply Units |
| Guaranteed software updates until | unknown |
| Item model number | 3S550B |
| Language | English |
| Manufacturer | Eaton |
| Product Dimensions | 32.5 x 8.6 x 14 cm; 3.8 kg |

## Product Details

- **Battery cell composition:** Sealed Lead Acid
- **Brand:** Eaton
- **Colour:** Black and white
- **Material:** Metal
- **Voltage:** 230 Volts

## Images

![Eaton Serie 3S UPS 3S550B – 550VA 330W Off‑Line Backup Power, Quiet Fan‑less Design, 6× UK BS Outlets with Battery & Surge Protection, USB HID Interface, Black & White (B0B3RS2986) - Image 1](https://m.media-amazon.com/images/I/71y7kOd3vbL.jpg)

## Available Options

This product comes in different **Size, Version For Country** options.

## Questions & Answers

**Q: How would this help my synology nas? would it help to safely power down the nas during power cut ?**
A: Yes it would. I have my Synology NAS and my router both connected to this. In the DSM Control panel under "Hardware and Power" there is an UPS option. If you tick "enable UPS support" you can select a suitable time after a power loss when the NAS will go into standby mode thus avoiding any possible file corruption.

**Q: I've just taken delivery on one of these and I'm trying to get the breaker button to work, it just fell inside the device?! Anybody else had this?**
A: Think you will have to send it back sounds broken to me we sent ours back as it was not doing what we though it might to turns out we just needed a new fridge LoL 🤣

**Q: Would this run or keep running a fridge freezer please ?**
A: I can't say for certain, but i very much doubt it could run a fridge/freezer as they have electric motors and require a lot of power.

**Q: The link to the power management software (in the supplied paperwork) is dead. Can someone please provide the link for me?  Thanks**
A: I just noticed this is a 60 day trial.   Pretty poor that they don't bundle any control software with it.  Has anyone tried it?  Found a better solution?

## Customer Reviews

### ⭐⭐⭐⭐⭐ Takes mains outages in its stride
*by P***B on 22 November 2023*

I bought this UPS a couple of months ago because the mains was becoming unstable with the lights flickering badly etc. (later traced by the utility company to a poor connection out in the street). Two days after I installed it and connected my PC, Router and Smart TV, the mains went unreliable with more flickering lights and clocks resetting etc., but the connected router and PC just continued working as normal. There have been a couple of momentary mains outages of a few seconds since and again the PC etc. had no problems. I also discovered on the Eaton website there's a form to fill in for the monitor software, I put something like private domestic user and was sent a link to a slightly older but perfectly functional and useful piece of software to monitor the current status and alarms. The distance between the two rows of sockets for filtered and filtered+UPS is larger than on some other UPS units which means some bulkier adaptor type plugs rather than the normal plug size can be accommodated. It also has a slide out panel on the base giving access to the battery which means it can easily be swapped out when at the end of its serviceable life. This makes me think this is a unit built to last. I am very pleased with my purchase which is performing flawlessly and wouldn't want to be without it.

### ⭐⭐⭐⭐⭐ Brilliant and saved my RAID drive a couple of times....
*by A***E on 23 November 2022*

A great looking and compact UPS and easy to mount. I've used the mounting holes that's meant for walls and reinforced it with a couple of heavy duty straps under my height adjustable table, because I didn't want a number of un-sightly cables risk getting caught as I raise my desk. On one side of the strip is surge protection and the other uses the UPS, I didn't know this at first as I skipped the instructions and was wondering why it wasn't working! I got this was for my NVMe RAID which is very sensitive when power is suddenly cut and I risk a 2 day rebuild/re-install, I've already had it come on twice when the lights started flickering and thank goodness I had this. It comes with a long USB cable for communication and my Mac already has a fantastic built-in feature that brings-up a message in the middle of the screen, warning you're now running on UPS battery and to save/back-up etc. there's also a battery level indicator on the desktop strip. I'm running a power-hungry 40inch curved LG monitor, a RAID SSD and NVMe RAID, Macbook M1 Max, various SSD HD, a Thunder Bolt 4 hub and a Wifi6e router - when the power goes, there is a low level alarm and I get around 7 minutes to save and power down, which is more than enough, but luckily we only get very short power outage in London. Highly recommended and everyone should get one to protect their IT equipment.

### ⭐ Batteries failed prematurely - may have no minimum voltage cut-off
*by A***A on 9 July 2023*

I own three of these units. Two worked great during a power cut yesterday, but one of them instantly dropped the output power. They are all around 12 months old. The one unit which failed had actually been fully discharged once, several months ago during a previous power cut. The other two units did not fully discharge, because they have very light loads (~3 watts vs the ~9 watts attached to the failed unit). Both of the lipo cells inside (TP LI-ION 3.7V ICR18650 2200mAh MH46259 UD020) now read at roughly 0.125 volts, so my /assumption/ is that these are unprotected cells and the unit itself does not have a low-voltage automatic cutoff. This is extremely problematic, because whenever there's a lengthy power cut, there is a solid risk that the unit itself will then be bricked unless you want to manually replace the lipo cells inside. So I'm afraid I need to give the "overall rating" as just one star because of this. Sorry, Eaton. Unless I'm mistaken and the one unit is faulty, then you will need to release a revision 2.0 which includes proper cell protection. Ideally they would auto power-off at, say, 20% power remaining. Perhaps even make the percentage/voltage configurable with a DIP switch somewhere, but obviously a DIP switch would add slightly to the materials cost & the plastics would need redesigning, so a straightforward X% cut-off would be the most reasonable thing to implement.

## Frequently Bought Together

- Eaton 3S 550B UPS - Off Line Uninterruptible Power Supply - 3S550B - 550VA (6 BS outlets, USB, Quiet, Shutdown software) - USB Interface (cable included) - Black&White
- APC by Schneider Electric BACK-UPS ES - BE850G2-UK - Uninterruptible Power Supply 850VA (8 Outlets, Surge Protected, 2 USB Charging Ports), Black, Pack of 1

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*Product available on Desertcart Finland*
*Store origin: FI*
*Last updated: 2026-02-27*