Help me pick a UPS

[de.das.dude]

UPSes tend to charge slow. Give it a full day online for max battery life.

i looked it up in its spec sheet. Says it needs around 6hrs for full charge. Oh well, i will repeat the test tomorrow as well.

 

[Bill_Bright]

It's a 3D printer

Ah! Thanks for that. I thought it was a typo!

Laser printers use muuuuch more power than that.

I seriously doubt that, the hotend and heated bed on an Ender 3 should be something like 50W minimum, sustained.

Yeah, 50W is nothing. Dr. Dro is correct. Laser printers are power hogs - particularly when starting (powering on/waking from sleep) and when printing. Remember, they use heat to "fuse" the toner to the paper.

If you look at the specs for the popular $200 Brother DCP-L2640DW/DCP here, it shows power consumption of 470W while printing and a whopping ~920W peak demand!

Look at this HP Color Laser MFP 3301fdw. It consumes 416W while printing. Sadly, it does not state peak demand. It should, IMO.

Fortunately, most printers sleep most of the day and those Brother lasers consume less than 5W during that time. That HP is just .95 in sleep mode.

with a power factor of .983 for my PSU, around 400VA

Sorry, but I think you are confusing efficiency with power factor. They are not the same thing. But more importantly, for this discussion, we are not talking about power supplies. This discussion is about UPS. PF is not the same for PSUs and UPS because one converts AC to DC, the other converts DC to AC (actually, AC to DC then back to AC).

The UPS does not care what the power factor (or even efficiency) is of our power supplies. The UPS only cares about the demand (in watts) from the connected devices.

For UPS, unless specified, typical power factors are around .6 to .8. As seen by this APC FAQ, they use a PF of .7 for their general guideline. Depending on the specific UPS model, it may be higher, or lower than that. Some are as low as .35.

To illustrate further, if you look at this Cyberpower GX1500U UPS, it is rated at 1500VA/900W. That means it is rated on a power factor (PF) of .6.

1500VA x .6PF = 900W

UPSes tend to charge slow.

Right. They could easily make them charge more quickly but that would require higher capacity charging circuits. Easily doable, but at a higher cost. Also, the physical size and current capabilities of the components for such a higher capacity would (1) require a larger UPS case to fit and result in the generation of more heat while charging. And then (2) that extra heat may need a fan (I hate fan noise) or larger heatsinks.

Faster charging also tends to cause the batteries to heat up more - and as noted by that line in my sig, "Heat is the bane of all electronics" - including batteries. So a slow charge is not only cheaper to make, it is easier on the batteries too.

i looked it up in its spec sheet. Says it needs around 6hrs for full charge.

That probably is from a fully discharged state. But waiting over night is probably better to be sure a full charge and cool batteries.

 

[Rover4444]

Yeah, 50W is nothing. Dr. Dro is correct. Laser printers are power hogs - particularly when starting (powering on/waking from sleep) and when printing. Remember, they use heat to "fuse" the toner to the paper.

If you look at the specs for the popular $200 Brother DCP-L2640DW/DCP here, it shows power consumption of 470W while printing and a whopping ~920W peak demand!

Look at this HP Color Laser MFP 3301fdw. It consumes 416W while printing. Sadly, it does not state peak demand. It should, IMO.

Fortunately, most printers sleep most of the day and those Brother lasers consume less than 5W during that time. That HP is just .95 in sleep mode.

I think you're overestimating how much you'll use a laser printer and underestimating how much power a 3d printer can consume. You would have to run that laser printer for over two hours to consume the same amount of power a 24hr 50W continuous 3D print takes, and you're much more likely to do the latter with an Ender than the former with a Brother.

Regular printers shouldn't need an UPS anyways while with a 3D printer it's a good idea because the print will lift off the bed during power off and ruin hours of printing.

 

[Shrek]

Since modern PCs run at a power factor of close to 1, only the Watt rating of the UPS is relevant (ignore the VA rating)

 

[de.das.dude]

Soooo.. with just some youtube videos playing in the background and with some casual amazon web browsing, its been 20minutes now... still working

Not bad for now.

EDIT 30 mins

 

[Bill_Bright]

I think you're overestimating how much you'll use a laser printer and underestimating how much power a 3d printer can consume.

Huh? Don't be silly. I provided links to actual laser printers. I did not estimate (over or under) anything.

If anyone did any underestimating, it clearly is you for saying just 50W.

If you bothered to look at the links I provided, you would see the consumption rates are over 400W when printing and over 900W when starting/warming up.

Then if you bothered to look at the specs for an Ender V3 as seen here, it has a maximum power consumption of 350W.

As for how much I'll be using any printer that does not mean anything. A printer will consume X watts while printing regardless if printing 1 page per month or 100 pages per day.

I don't know. A printer at 50W for 24 hours uses more power than a 314W+ printer for one hour

That's even sillier. It is not a valid comparison. Power "use" over a period time is NOT THE SAME as power demand at any given moment. And the power demand at the moment is what UPS are all about.

You are talking kWh vs watts. NOT THE SAME THING.

Since modern PCs run at a power factor of close to 1, only the Watt rating of the UPS is relevant (ignore the VA rating)

This has been a pet peeve of mine for awhile. Shrek is 100% correct. There is no reason us consumers need to be concerned with VA ratings. We only need to worry about the demand in watts when sizing up a UPS for purchase.

I can only assume UPS are rated in VA because of marketing weenies! 1500VA "sounds" more powerful than 900W.

Regular printers shouldn't need an UPS anyways while with a 3D printer it's a good idea because the print will lift off the bed during power off and ruin hours of printing.

It is true stopping a 3D printer in the middle of a print job would not be good. So for that reason, having the 3D printer on a good UPS is a good ideal in the event of a power outage. But I sure would recommend it be on its own UPS and even then, it would be wise to press the printer's pause button, then shut down the printer properly until grid power is restored. Then the print job can resume where it left off.

Edit comment: fixed Ender link.

 

[unwind-protect]

I use this sucker on my big computer. Never noticed a thing, so I guess it just works.

Amazon.com

 

[Bill_Bright]

Wow. Last time I looked at that CyberPower (99% sure same model number), I think it was $329. Good to see prices coming down.

 

[Rover4444]

Huh? Don't be silly. I provided links to actual laser printers. I did not estimate (over or under) anything.

If anyone did any underestimating, it clearly is you for saying just 50W.

If you bothered to look at the links I provided, you would see the consumption rates are over 400W when printing and over 900W when starting/warming up.

Then if you bothered to look at the specs for an Ender V3 as seen here, it has a maximum power consumption of 350W.

As for how much I'll be using any printer that does not mean anything. A printer will consume X watts while printing regardless if printing 1 page per month or 100 pages per day.


That's even sillier. It is not a valid comparison. Power "use" over a period time is NOT THE SAME as power demand at any given moment. And the power demand at the moment is what UPS are all about.

You are talking kWh vs watts. NOT THE SAME THING.


This has been a pet peeve of mine for awhile. Shrek is 100% correct. There is no reason us consumers need to be concerned with VA ratings. We only need to worry about the demand in watts when sizing up a UPS for purchase.

I can only assume UPS are rated in VA because of marketing weenies! 1500VA "sounds" more powerful than 900W.


It is true stopping a 3D printer in the middle of a print job would not be good. So for that reason, having the 3D printer on a good UPS is a good ideal in the event of a power outage. But I sure would recommend it be on its own UPS and even then, it would be wise to press the printer's pause button, then shut down the printer properly until grid power is restored. Then the print job can resume where it left off.

Edit comment: fixed Ender link.

I'm sorry, but you either have absolutely no idea what you're talking about, or are intentionally being obtuse. First off, a battery's capacity is measured in Wh which is absolutely valid. Second off, you're not using "450W" worth of battery every time you print off a page. Third off, you are indeed overestimating how much you'll use a laser printer because even in your hypothetical scenario you're still not saturating the PPM of a laser printer for over an hour.

YOU might be talking about power demand, but I'M talking about power consumption, because when you actually buy a system that's rated for your surge, intermittent, and continuous loads, it's the only thing that actually matters. Keeping up your appliances for as long as possible during an outage is ONE HUNDRED PERCENT the goal of an UPS.

I indeed may be underestimating the power consumption of an Ender, that's what minimums are. And you should NEVER shut down a 3D printer during a print, you will interfere with any power-loss recovery functions it has. At best pause the print and pray your UPS has enough charge to keep the bed warm.

 

[Endymio]

YOU might be talking about power demand, but I'M talking about power consumption, because when you actually buy a system that's rated for your surge, intermittent, and continuous loads, it's the only thing that actually matters.

That's even sillier. It is not a valid comparison. Power "use" over a period time is NOT THE SAME as power demand at any given moment. And the power demand at the moment is what UPS are all about.

You both might communicate better if you'd use the proper terms and units. Watts are power, Watt-hours are energy. When sizing a UPS, both matter -- if the UPS can't handle the peak power, it'll fault immediately. Run time, however, is a function of energy capacity. Two units may be both rated at 900W (or 1500 VA), but one might exhaust itself in five minutes, while the other last an hour.

 

[de.das.dude]

So... I let the UPS charge overnight, all day, tested it after i got back from work with stress test.

Lasted only 5min. This is supposed to have 2x 12V 9aH batteries. Something is of? as per my calculation i should get atleast 15minutes?

 

[unwind-protect]

So... I let the UPS charge overnight, all day, tested it after i got back from work with stress test.

Lasted only 5min. This is supposed to have 2x 12V 9aH batteries. Something is of? as per my calculation i should get atleast 15minutes?

Step back a bit. Which UPS did you get?

What is the actual power draw of your computer? The UPS should display that.

Are you testing idle or with a game loaded? Monitor connected to the UPS?

 

[Assimilator]

So... I let the UPS charge overnight, all day, tested it after i got back from work with stress test.

Lasted only 5min. This is supposed to have 2x 12V 9aH batteries. Something is of? as per my calculation i should get atleast 15minutes?

Probably because your calculations of how much power you need are based on your faulty assumption that the system draws a maximum of 380W, instead of measuring the actual draw at maximum load. The FX 8320 is a massive turd of a CPU that can draw upwards of 200W when loaded and the RX 580 is rated up to 185W - the sum of those is already over your estimate, without considering any other devices like monitors.

But over and above that, how much load you put on a battery affects how long it can discharge for. The relationship is not linear because as a battery discharges, some of its stored energy is lost as heat - but also the hotter the battery becomes, the more its resistance increases, so the more energy it loses... in short you end up with a vicious cycle. This is one reason why name-brand UPS models cost more - they use better-quality batteries that generate less heat and thus lose less energy (and this is also one of the reasons why lithium-ion batteries are so expensive: they're very good at not heating up when loaded).

When you got 30 minutes with the system at idle, it's because the power draw was low enough to keep energy losses and heat build-up to a minimum. When you blasted it with the full force of your FX 8320 the power draw went up and so did the heat and losses. This is what people have been trying to tell you: a UPS, especially a cheap consumer model, is simply not designed for long runtimes. And given that you bought a no-name brand, the batteries are likely not true 9ah units at all... or they are 9ah at a stupidly low draw that nobody using a 1500VA unit would reasonably be expected to use.

 

[Bill_Bright]

So... I let the UPS charge overnight, all day, tested it after i got back from work with stress test.

Lasted only 5min. This is supposed to have 2x 12V 9aH batteries. Something is of? as per my calculation i should get atleast 15minutes?

I agree. That does not sound right - IF you are calculating that correctly. Like @Assimilator, I am not so sure that is the case.

Please list exactly what you have connected to the battery side of that UPS.

And what do you mean by "testing with stress test"? Understand, stress testing a computer is NOT realistic. That is, it does not represent real-world scenarios which UPSs are designed for.

For example, in the real-world it would be extremely rare for the CPU, GPU, RAM, motherboard, all fans, all drives to be demanding maximum power at the exact same point in time. But many stress tests do just that.

And note printing takes very little computer resources. It mostly is just spooling data from a drive to the printer. And depending on the size of the buffer in the printer, much, if not all of the print job could be handed off to the printer very quickly. If you were printing a documetn (or 3D print job) when the power went out and quickly powered off your monitors and stepped away from the keyboard, you should have a lot more battery runtime left.

You should set up a real-world scenario and try it.

But once again, the UPS is really there to give you enough time to "gracefully" save your work and shutdown the computer. If you need more time, a backup generator is the way to go.

Once fully charged, what does the UPS LCD display panel say you have for estimated runtime?

What does the UPS display panel say is your current power demand? Do you have a kill-a-watt meter? These are very handy for projects like this.

Also, are you running the UPS software? Not sure about Cyberpower's "PowerPanel" software but APC's PowerChute software lets users configure the shutdown timing. For example, I can set it to "Preserve battery power" which will shut down the computer in 5 minutes, or I can tell it keep the computer on as long as possible, then it will shutdown the computer when there is only 7 minutes of runtime left.

If you are not using the interconnecting cable or UPS software, it may default to the shutdown right away option.

FTR, the way we test UPS here is a lamp. I have a table lamp with two 150W incandescent lightbulbs. With the lamp plugged into the UPS and the lightbulbs lit, pulling the UPS plug from the wall should keep the lightbulbs lit.

Anecdotal but with this computer right now (as shown in my system specs), as well as my wireless router, and cable modem, this 1500VA/865W APC UPS has an estimated runtime left of 42 minutes. Admittedly, typing this while streaming Pandora music is not very demanding but that is also running with two 24 inch monitors. If I shut down those monitors, this UPS will keep my network alive for an estimated 87 minutes. Longer if I quickly shut down the computer too.

You both might communicate better if you'd use the proper terms and units. Watts are power, Watt-hours are energy.

I did. That's why I said above kWh and watts are not the same thing.

When sizing a UPS, both matter -- if the UPS can't handle the peak power, it'll fault immediately.

I totally agree. This is why I said above, the larger the VA/Wattage rating the longer the battery runtime.

Third off, you are indeed overestimating how much you'll use a laser printer

Bullfeathers. Please show everyone where I provided any estimate concerning how much anyone will be using a laser printer.

Regardless my point remains the same and ties directly to @Endymio's point. The laser printer will demand the exact same amount of power to print 1 page in a 1 page document as it does to print 1 page in a 100 page document. Or, as I said above, "A printer will consume X watts while printing regardless if printing 1 page per month or 100 pages per day."

 

[Rover4444]

Bullfeathers. Please show everyone where I provided any estimate concerning how much anyone will be using a laser printer.

Regardless my point remains the same and ties directly to @Endymio's point. The laser printer will demand the exact same amount of power to print 1 page in a 1 page document as it does to print 1 page in a 100 page document. Or, as I said above, "A printer will consume X watts while printing regardless if printing 1 page per month or 100 pages per day."

"100 pages per day" is an estimate, one that I assume is hyperbolic. You're using a printer for less than fifteen minutes at double-sided PPM, and that's a much less likely scenario than an Ender running overnight.

Yes, it does demand that amount of power. Of course you're supposed to buy a unit that actually fits your load, but runtime is always the main concern when buying an UPS - as OP is now learning.

 

[Bill_Bright]

"100 pages per day" is an estimate, one that I assume is hyperbolic.

So what? You just don't get it.

What does that have to do with picking the right size UPS??? Absolutely nothing!!!!

If mission requirements require the user has the ability to print 100s of pages during a power outage, they need to be on a generator, not just an UPS.

Move on!

 

[Rover4444]

So what? You just don't get it.

What does that have to do with picking the right size UPS??? Absolutely nothing!!!!

If mission requirements require the user has the ability to print 100s of pages during a power outage, they need to be on a generator, not just an UPS.

Move on!

Then why did you even mention that like it's an actual usecase for an UPS, then? This is what I mean by being willfully obtuse.

I think we're mostly in agreement with each other, I'm just not getting the hold-up. The other guy found out what I meant after explaining myself a bit...

 

[Bill_Bright]

Then why did you even mention that like it's an actual usecase for an UPS, then? This is what I mean by being willfully obtuse.

How about you being dense?

Look at your own post number #28 above. You quoted me where I estimated NOTHING. I listed links to actual specs provided by the manufacturers showing how much power they demanded. Yet you claimed I overestimated use and underestimated power. I DID NOTHING OF THE SORT.

Then you rambled on about running a laser for 2 hours vs a 3D printer for 24hours when that has absolutely nothing to do with anything I said.

My comment was there because YOU, not me, but YOU incorrectly claimed Dr. Dro was wrong when he said lasers use much more power than the 3D printer. He was right. And I showed you (with links) how lasers can use over 900W and that 3D printer only 350W.

"100 pages per day" is an estimate

No it isn't! Do you not know what an arbitrary number is? Do you not understand the definition of the word, estimate.

That "100" was simply an arbitrary number pulled out of the air to illustrate a point. I could have easily said 50 pages per day, 100 pages per hour, or 10,000 pages per month. It does not matter. The point I made is still the same: it still takes the same amount of power to print page 1 of a 1 page doc as it does to print page 1 of a 47 page doc. Not one of those numbers are estimates.

So obtuse or dense, doesn't matter. It is not me being it.

 

[de.das.dude]

@Bill_Bright i only have my PC connected. the case consumes a total of 420W at peak, factoring in efficiency of the power supply, lets say its 500W.

Add my monitor, which is peak 30W but i use only 20% brightness, so lets say 20W, being reasonable. I have a speaker with sub, which is 80W total.

lets make the round figure to 600W right?

based on this i should get around 20 minutes. But i am getting only 5 minutes while doing a CPU + GPU stress test from AIDA64.

According to the 12V 9ah X2 battery pack, this means i am running a load of over 2000W.

btw you can use chatgpt for calculations, after some tweaks it does have a good calculation.

Anyhoo. I asked for a replacement from amazon.

"100 pages per day" is an estimate, one that I assume is hyperbolic. You're using a printer for less than fifteen minutes at double-sided PPM, and that's a much less likely scenario than an Ender running overnight.

Yes, it does demand that amount of power. Of course you're supposed to buy a unit that actually fits your load, but runtime is always the main concern when buying an UPS - as OP is now learning.

this is no relevant. lol. i am not running a laser printer nor a 3d printer.

 

[Rover4444]

How about you being dense?

Look at your own post number #28 above. You quoted me where I estimated NOTHING. I listed links to actual specs provided by the manufacturers showing how much power they demanded. Yet you claimed I overestimated use and underestimated power. I DID NOTHING OF THE SORT.

Then you rambled on about running a laser for 2 hours vs a 3D printer for 24hours when that has absolutely nothing to do with anything I said.

My comment was there because YOU, not me, but YOU incorrectly claimed Dr. Dro was wrong when he said lasers use much more power than the 3D printer. He was right. And I showed you (with links) how lasers can use over 900W and that 3D printer only 350W.


No it isn't! Do you not know what an arbitrary number is? Do you not understand the definition of the word, estimate.

That "100" was simply an arbitrary number pulled out of the air to illustrate a point. I could have easily said 50 pages per day, 100 pages per hour, or 10,000 pages per month. It does not matter. The point I made is still the same: it still takes the same amount of power to print page 1 of a 1 page doc as it does to print page 1 of a 47 page doc. Not one of those numbers are estimates.

So obtuse or dense, doesn't matter. It is not me being it.

Dang dog, that's a lotta words. You're right, I concede the argument.

this is no relevant. lol. i am not running a laser printer nor a 3d printer.

I know right lmao. I do still recommend a solar generator with UPS functionality though, you don't have to pay the running costs associated with most UPS for the most part.

 

[Bill_Bright]

First, speakers should never be on the battery side of the UPS. If you truly need sound during a power outage, have earphones handy to plug in.

According to the 12V 9ah X2 battery pack, this means i am running a load of over 2000W.

You can't go by that because the electronics in the UPS itself are a key factor in total run time. If you do some research, you will find many UPS of different capacities use 2 x 12V9Ah cells in their battery packs. In fact, I have several UPS here that originally used 12V7Ah cells. When they eventually died (as all UPS batteries will, typically in 2 - 5 years) I replaced them 12V9Ah cells. That increases runtime, but not load capacity because the electronics limits that.

Note you can always replace the cells with higher Ah ratings, not lower (assuming physical dimensions are the same - as many are). But the voltage must be the same. And terminal sizes (typically F1 or F2) should be the same. Adapters are available but most battery compartments are already a very tight squeeze.

What are you using for a power factor in your calculations. Since that UPS is rated at 1500VA and 900W, that means they are using a power factor of .6.

1500 x .6 = 900.

According to Cyberpower, that should give you about 11 minutes of runtime. APC says about 10 minutes.

the case consumes a total of 420W at peak

How did you determine that? Unfortunately, I don't see where that Artis supports an interconnecting cable or monitoring software. You really need to actually measure your consumption. I would suggest looking into one of those kill-a-watt meters designed for your outlets and voltage.

And I would not assume 20W for your monitor unless you actually measured it. Of course my monitors are not yours but my 24" Samsung demand about 40W and I just played with the Brightness settings and didn't get 10W difference between 71% (my normal setting) and 30%.

But i am getting only 5 minutes while doing a CPU + GPU stress test from AIDA64.

Again, that's not a real world scenario.

 

[Endymio]

Probably because your calculations of how much power you need are based on your faulty assumption that the system draws a maximum of 380W, instead of measuring the actual draw at maximum load. The FX 8320 is a massive turd of a CPU that can draw upwards of 200W when loaded and the RX 580 is rated up to 185W - the sum of those is already over your estimate, without considering any other devices like monitors.

But over and above that, how much load you put on a battery affects how long it can discharge for. The relationship is not linear because as a battery discharges, some of its stored energy is lost as heat - but also the hotter the battery becomes, the more its resistance increases, so the more energy it loses... in short you end up with a vicious cycle.

All entirely correct. But add that PC power supplies are not 100% efficient. To the total draw of all components, you must add another 10-30% consumed by the PSU itself.

I did. That's why I said above kWh and watts are not the same thing.

But you incorrect called both "power", then compounded the error by claiming that only "watts" were relevant when sizing a PSU. Move on.

 

[Shrek]

But add that PC power supplies are not 100% efficient. To the total draw of all components, you must add another 10-30% consumed by the PSU itself.

But those loses are just when the UPS kicks in (assuming it is not an online UPS)

 

[Endymio]

But those loses are just when the UPS kicks in (assuming it is not an online UPS)

Eh? Your PC PSU losses are there 100% of the time, UPS or not. Not that it's relevant to the point of runtime of a UPS, which presupposes it is engaged.

 

[Bill_Bright]

But add that PC power supplies are not 100% efficient. To the total draw of all components, you must add another 10-30% consumed by the PSU itself.

But those loses are just when the UPS kicks in (assuming it is not an online UPS)

Eh? Your PC PSU losses are there 100% of the time, UPS or not. Not that it's relevant to the point of runtime of a UPS, which presupposes it is engaged.

Yeah, Endymio is correct there. The PSU's efficiency is a factor at all times it is supplying power. But it is not constant as that varies by the load the components inside the computer case put on the PSU. So if the components are demanding 300W from a 600W PSU, and the PSU is 90% efficient at 50% load, then the PSU will demand from the UPS ~333W (333 x .9 = 299.7) - regardless if the UPS just kicked in, or has been supplying power for several minutes.

This is where a kill-a-watt meter can come in handy if the UPS does not have a status display screen.

But you incorrect called both "power", then compounded the error claiming that only "watts" were relevant when sizing a PSU. Move on.

Bullfeathers! Please show everyone where called both kWh and watts power. You just quoted me when I said they are not the same thing. Then show us where I said only watts were relevant - and this time, do NOT take just a portion of my comment out of context. That is not cool.

I specifically said that I agreed with you when you said "both matter" as in both watts and energy. I even went on to say the larger VA/Wattage ratings result in longer battery runtimes.

The TRUTH about what I REALLY said about only watts being relevant was in direct response and agreement with Shrek who said in reference to sizing UPS and looking at the VA spec and the watts spec was,

only the Watt rating of the UPS is relevant (ignore the VA rating)

And that is 100% true. When looking at the just the VA and watts specs of a UPS, only the watts is relevant.

If you are going to take people's words out of context, be honest about it. Don't take only a portion then claim they said something different. It would behoove you not to be deceitful like that where everyone can simply go back and see the truth for themselves.

Move on.

And you too.