PSU Low-end UPS recommendations

Not sure what will happen to you directly, even though I have seen some pretty nastly melted battery packs. They use el'cheapo chinese CSB rubbish which quite often dies the way you have to use almost heavy machinery to dig it out of them. Did I mentioned they have quite short life span?

As for the UPS itself, they use crap capacitors and on purpose place them next to hot spots. Usually they can live quite for some time, but I worked mostly with older units, no idea about newer ones. They mainly milk people through batteries but who knows, todays electronics is so screwed, 2/3 of electronics is made to die shortly after the warranty expires.

Strange firmware accidents also happen more than often. We have a saying here, it goes like "I am not so rich to buy cheap things". Cheap craps usually last fraction of time the quality device does. Don't forget about the efficiency as well, it's basically special type of SMPS.

I suggest avoiding the cheapest offerings, it's just hub with battery. Go for stand-alone, true UPS, all of these are at least line-interactive.

 

I'm trying to work out how little I can spend to get something that will work and won't act like a space heater or musical instrument while the power is up for 99.9% of the time.

I imagine the devices are going to be <10W so any battery is going to give us a lot of time. But it does need to gope with whatever the grid throws at us and we do get quite a few powercuts a year, particularly in the winter when the telegraph poles start falling over.

 

Risky; I have an APC UPS I could sell you for pretty cheap as I got it free from work and it's too low of a power rating for what I need it for. Let me check the details of it when I get home tonight and I'll send you a PM.

 

Most of the "hubs with battery" are, to my knowledge, off-line types. They only protect from "high" voltage spikes thanks to MOVs (like when lightning hits the grid 10 km away from your house, but these spikes are much more common than that), do not protect from lower overvoltage (e.g. 300 V) and not at all from undervoltage (unless it goes so low to trigger battery-operation). I also heard about cases where the power was so bad such UPS was quite often switching very fast to battery and back because of that. I guess you can imagine what it did to batteries.

For that reason I suggested line-interactive. There is also one thing which I can only guess as there is no statistic or anything. But probably the cheaper and simplier/"dumber" the UPS, the more likely it does not produce anything at all close to sine-wave. That may not be a problem for phone/switch/router adapter, if you would like to connect some SMPS with active PFC to that in future, it may not go well.

ADD// just got Back-UPS "hub with battery" for repair. Customer had two, one supposedly died after 4 years, this is to have "almost-dead" condition. I am kinda busy now but should be able to take a look in a few weeks. Can post some internals if you are interested.

 

Just 2 cents, that hub-with-battery has been sucessfully repaired. I learned whole new capacitor brand, of course each single cap from that was replaced.

Probably the greatest problem are cheap craps used on primary filtering for internal PSU powering the circuitry. From what I have seen and heard, they go kaboom or bring the primary side to explode. That is not surprising after all, usually the affects are very bad when something goes wrong on 325+ V.