Eaton Serie 3S UPS 3S550B – 550VA/330W offline backup power for reliable protection, quiet operation for home and office use, 6 BS outlets with USB interface, Black/White (B0B3RS2986) – United Kingdom, G...

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.

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.

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.

Edit. 2 years later I’ve repeated some full discharge and recharge tests, including discharging it at the max rated 36Watts and unlike others still have has no problems with the recharge sequence. The failure of the low cell voltage protection reported by some hasn’t occurred on my unit. This Eaton3S and the APC CP12036Li remain the best options available for anyone looking for a small DC UPS with a recognised name. Nicely made mini UPS from a recognisable name, with a 2 year warranty its got the feel of a quality product. Well documented. It has some nice features, like switchable output voltage level and a relatively high supply rating of 36Watts. I've run some12V load tests when on battery and the output voltage only dropped from [email protected] to 11.3V@3A. The DC output level was also maintained well as the battery ran low . By including the AC/DC conversion inside the unit there is only space to include 2 off 2200mAH lion cells, so overall capacity is a fairly small but usable 11.9Wh (measured). So it should be able to run a typical small router (5-6Watts) for around 2hours, that's probably long enough for most typical mains power interruptions. The battery recharge rate is a relatively low 4Watts so once mains power is restored it does take around 5Hours to fully recharge . Once fully charged the UPS appears to use <1W to manage its own functions To make it a better prospect than its competitor MiniDC UPS What it ideally needs is either larger internal batteries or perhaps the ability to recharge from an external powerbank. The case would benefit from some mounting holes and there's also no audio warning to indicate 240V power failure. It is however one of the few MiniDC UPS that I'd be content to leave running unattended in my house 24/7/365.

I use it for my homelab that runs TrueNAS CE, and it is supported and works really well. I don't have any complaints! Does exactly what it is meant to do.

I live in an area subject to irregular, but relatively frequent, power cuts. Four in the last month, each for a variety of reasons, and each lasting a couple of hours or so. The usual apologies from the supplier (Northern Powergrid) but no confidence matters will improve anytime soon. When they're blaming squirrels you know you're in trouble... Unfortunately, the mobile networks go down too, so our entire village goes off the comms grid. With BT digital voice allegedly coming next year we will be deprived even the trusty landline. So some kind of contingency makes sense, if only for emergencies. There are any number of these units on Amazon, and you have to pick one, so the Eaton 3S mini was it. Arrived in a couple of days. Easy to set up. Although it has 4 dc power outputs the default setting is 12V, fine for the BT hub we have. There are 4 barrel connectors included, one being 3.00mm which is compatible with the modem. It fits, and that's good enough for me. Took about 10 mins max to install, let it charge overnight, then switched off the mains power to the hub this morning. The latter continued to function. So far so good. We'll have to wait for another power cut to test in in real world conditions, but assuming the back up batteries in the BT street boxes are good for a couple of hours then we should be ok. We'll see. Update 4 July 2024 Another power cut this afternoon. 6 now in 7 weeks. Step forward Northern Powergrid... We were reconnected to the mains supply after 1 hour 45 mins or so. The backup battery kept us connected but judging by the status lights on the front I guess we had another 15 mins tops. So 2 hours powering a standard BT modem

As the title says, this beautiful device has come in handy so many times i don’t want to even think about. Had a number of power cuts in the last few months, and this has been such a life saver to safely turn off the products. Fairly heavy, and a bit large, but overall a great product. Great power supply for tv, pc etc. battery life is at best depending on your needs, about 15 minutes, but plenty to turn off before it dies. USB ports, sadly my one has defective ports in that regards, but isn’t to much of an inconvenience for me, but small inconvenience. Noise, personally, I haven’t noticed anything sound wise. The device is extremely silent, however there is a sound when power is cut off, and is quite noticeable, but a loud sound is needed for if power is cut. Very useful. I’d say in the long run, it might seem like a lot to pay because it is, but i honestly think that once you have a power cut or supply issues at it’s value is well worth the price. Would definitely recommend

I have a fairly decent PC with RTX graphics and recently we had a very short power cut. Whilst the extensions I use have surge protection I thought I'd look into something that would protect my PC from sudden and short power loss and found this EATON UPS which gives me around 10 mins cover for my PC. I've given 3 stars as an overall rating as the description says 8 power outlets of which 4 with UPS protection. The actual unit only has 6 sockets with only 3 outlets on UPS. This meant I couldnt cover the 2 x 4K monitors, PC and 4G router on UPS that I had hoped to protect. I could return to Amazon but deceide to protect 1 screen, PC and router rather than have the hassle. The UPS itself is easy to use. There a cable to connect the UPS to your PC and a downloadable software so you can see the current battery status and also change some settings. The software is basic, but doesnt seem to connect to the support site (which it should) for updates, so expect that needs to be done manually. There's 2 year warranty on the device. Registering was OK , but a bit tricky as the serial number I entered didnt seem to match their records, anyway you can force the registration through after that. Why ask questions on wifi signal and sleep mode on this UPS ? hence have given both 1 star , as its irrelevant. The unit itself is a brick, its solid construction, and fairly heavy . I have it on the floor under my desk. There's an on off switch and also a circuit breaker to protect the unit from overload. I have tested the unit by turning off the socket : immediately an audible alarm sounds but there was not drop in power to my PC or monitor and 4G router. As the power drains the software will , depending on setting, put your PC into sleep or shutdown. It will do this automatically at set-points (remaining battery % or remaining battery time) which you can set. Once power is restored the battery will reset. This is my first UPS , I am please with the purchase except for the error in the product description. Time will tell , how long this item last. Note: replacement batteries are available - I have not looked at the unit cost of the replacement battery pack, but I think its good that these can be purchased to extend the life of the UPS.