Eaton 3S Mini UPS 36W 9/12/15/19 DC protects your internet router, IP camera, home assistant and smart controller

The second chance ones have a high probability of damaged battery cells. I had to replace those,which is possible when you take it apart. But consider that it has no, again no, protection for deep discharging of the battwry cells inside. (2 x 18650)

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 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

II have not had a chance to actually use this device as the included barrel adapters do not include a 4.0mm (outer diameter) 1.35mm (inner diameter) one. This is the required size to fit an Asus router/repeater. So it could be 5 stars, but I will never know. I have looked if I can find something to reduce one of the included tips down to a 4.0x1.35mm tip, but cannot see one on Amazon. Updated a few days later: Managed to find an adapter online (not Amazon) for 5.5x2.1mm to 4.0x1.35mm Asus. It works well to protect the Asus routers, as you would expect for a UPS. Upgraded for 3 to 4 stars, but still minus a star for not having all the correct adapters in the box.