Planning an upgrade to Mac mini

MY MBP is old and tired. Moving away from an MBP battery “backup machine in case of a power failure”, what is the view of using an uninterruptible power supply (UPS). The UPS holding power is assumed to be a function of $$, i.e. longer time.

Does the Mini have enough capacitor power to back up memory to an external device?

recommendations appreciated.


A vanilla Mac mini will shut off almost instantaneously if you have an actual blackout. You will need a UPS to be able to buy enough time to graciously power down.

I use this with my two Mac minis:

macOS supports setting specific parameters for the computer to shut down based on various parameters (battery remaining, time remaining, x number of minutes after power outage), and I like CyberPower UPS specifically because they have the option to not beep when the power goes out.

“I like CyberPower UPS specifically because they have the option to not beep when the power goes out”

I loathe UPS beeps. Costco occasionally has a small selection of cyberpower upses on sale. I got two LE850G about 3 years ago and they’ve been great. When the wind blows, my power frequently flickers out for a few seconds. Now I hear clicks and the screen dims a bit instead of it all powering off half the time. I have the 27" imac, a 2011 mini, and the hard drives on one, and the dsl modem, time capsule and main switch on the other. The unprotected outlets feed a range of other stuff. In a real outage, I can connect the ithings or a laptop via wifi for awhile at least. Haven’t had a long enough outage to test how long the battery would last, though that doesn’t perturb me. In a major outage I’d turn it off unless I needed to use it to prolong the juice so it should easily go for days.

1 Like

I have a small UPS that I got for a printer and security cam router that must be the wrong wattage as it goes on and beeps every time I print. I think it has a silent mode, but I assume the draw it takes to wake up the printer and print is higher than what the UPS specs are. Would I be correct in that assumption?

I presume you have a laser printer or similar. Laser printers briefly use a substantial amount of power when they power up or wake from sleep, often in the range of ten times the peak load of an ink jet. This is because they operate by melting the toner powder after it has been applied to the paper. Since users expect to print quickly, a laser printer’s heating element needs to be heated quickly, which requires considerable power. In general, it’s not a major issue.

1 Like

Based upon experience, I tend to not trust UPS backups. We have frequent power outages here and they are usually preceded by flickering power which often confuses the UPS. I therefore don’t use any desktop machines - the laptop is the only machine I trust to handle power outages.

I do indeed. Thanks for the info

I’ve used an APC BackUPS 750 for years. An unintended benefit of moving from an iMac to a MBP a couple years ago is that I no longer need the UPS to keep the computer alive during a power failure. Now it’s only real job is to keep the external monitors and my hub and other critical peripherals running for as long as I care to keep working in a dark office.

TL;DR: There are a lot of different UPS models available, with a broad range of features and capabilities, and selling for a broad range of prices. Don’t just get an inexpensive unit without first checking to see if it meets your needs. But also don’t assume that an expensive unit will get the job done without checking its specs.

And now the long-winded responses:

UPS’s have two properties you need to keep in mind for selecting any model from any manufacturer:

  • Maximum load - that is, the maximum amount of power (expressed either as VA (AC) or Watts (DC)) that can be drawn before it overloads and shuts down.

    Note that a US-standard power outlet (120 VAC on a 15A circuit) is not going to be able to supply more than 1800 VA without tripping the breaker. For this reason, you won’t find anything compatible with these outlets with a capacity larger than 1500 VA.

    Larger units (e.g. APC makes 2000, and 3000 VA models) will require a 20A or 30A circuit (and the corresponding receptacle). If you want to use one at home, you’ll probably need to have an electrician install the circuit.

  • Run-time. This should be a chart showing how long the battery will last for a variety of loads.

A high maximum load does not necessarily mean a long run-time and vice-versa. These two are independent variables. For example, in the past, I noted that APC made Smart-UPS units with 600 and 1000 VA capacity, but both had identical run-time for loads under 600 VA.

One annoying part is that UPS manufacturers usually advertise the maximum load on their packaging (typically as a part of the model number), but you usually have to go searching for documentation (usually on the manufacturer’s web site) in order to get the run-time chart.

Also note that some UPS’s can accept external battery packs. These will increase the run-time but will not change the maximum load. If you have too much equipment for one UPS, then you’ll need two or more units.

For example, consider the APC Smart-UPS SMT1500C:

  • The specifications show that the rated power is 1440 VA or 1000W
  • Its runtime graph shows that it will last nearly 3 hours at a 100W draw, 84 minutes at 200W, 50 minutes at 300W, down to 6.5 minutes at a maximum load of 1000W.

When selecting a UPS, you need to have a good estimate of the amount of power your connected equipment will draw. You can add up the numbers from all your devices’ documentation, but that will give you a theoretical maximum - actual usage will probably be much lower. If you already have the equipment, a power meter (e.g. a Kill-A-Watt device) can show you actual consumption, both instantaneous and average over time.

With that information, I recommend:

  • Make sure the UPS’s maximum load is double your actual consumption. Many models can become inefficient when loaded significantly beyond 50%. Additionally, if run-time charts are not available, manufacturers will usually post a run-time number for half-capacity.

  • Check its runtime chart to see how long you can run from batteries at that power level.

    • If it’s short (a few minutes), then that will be enough to stop what you’re doing and shutdown, but not much more.
    • If it’s long, then you can continue working through the outage.
    • Some models (especially more expensive ones) can accept additional battery packs to extend runtimes. So consider a smaller unit with extra batteries as a possibly more economical alternative to a large unit
  • Look for one that generates a pure sine-wave output. Cheap units generate a “simulated” sine wave, which may create problems for sensitive electronics. Modern computers can tolerate quite a bit, but bad quality power can still shorten the life of power supplies.

  • Look for a unit that includes a USB (or Ethernet) interface for monitoring.

    macOS includes software (part of the Energy Saver system setting - it will appear when a UPS is connected) for USB-based monitoring which will alert you when it switches to battery and can automatically shut-down when the battery runs low:

    You may need to install third-party software (often available from the UPS manufacturer) for Ethernet-based monitoring, but that (if your UPS has it) will let multiple computers monitor the UPS status, and can often support remote management.

No. No computer without a battery (like a laptop) can survive an outage longer than a brief flicker.

FWIW, my system has the following connected to my SMT-1500 UPS:

  • Mac mini (2018)
  • Display (Dell 2405FPW - 24" LCD)
  • Cable modem
  • Wi-Fi router
  • USB hub
  • The HDD I use for Time Machine
  • Raspberry Pi (running my DHCP and DNS servers)
  • My Ethernet switch (16 ports, Gigabit)

The total power draw when it’s all in use (according to the UPS’s front panel display) is 100-120W, and the expected run-time (again, according to the UPS’s front panel display) is about 2 hours. Which means I can continue to work through most outages.

This is actually the primary reason I bought such a large unit for my system - so I can work/play through all but the longest outages.

CyberPower makes good quality units. But they make a lot of different models, so be sure to read the specs. I personally wouldn’t recommend this unit. Keep reading for the reason why.

The Amazon listing says it has a maximum capacity of 510 W and at half-load (255 W), the battery will last 7.9 minutes. Which is enough time to save your work and shutdown, but not much more than that. This isn’t good enough for me, but it may be OK for your needs.

More problematic is the fact that this unit generates a simulated sine wave for output. As I wrote above, modern computers can usually accept this, but it is likely to shorten the lifespan of power supplies.

For CyberPower, if you want to get true (not simulated) sine-wave output, you need to select one of their PFC Sinewave series of products. The PFC equivalent (similar capacity and run-time) to the one you selected is the CP850PFCLCD (runtime chart). It’s a bit more expensive ($155 from Amazon, $170 from the manufacturer’s page), but I think the difference is important.

Never put a laser-like (laser, LED, etc.) printer on a UPS. They have large inrush currents when waking from sleep (e.g. to heat up the fuser unit) and can draw quite a lot of power while printing. This will overload all but the largest UPSs, and even those products tell you to not try it.

For your printer, use a good quality surge suppressor/power filter, but don’t plug it in to a UPS’s outputs.

It depends on the model you get. This may confuse a cheap unit. But good ones should include features to correct power that is present but bad (voltage spikes, sags, transients). The buzzword for this is “AVR” (automatic voltage regulation).


It’s enough for me. I have the mini set to shut down two minutes after a power outage (so that it won’t shut down over a mere blip) and I also have my cable modem, 24 port switch, and router plugged in, and that gives me over an hour of internet time. If it’s still out after 15 minutes I’ve started my generator by then and the UPS is getting power again.

The important thing is no beeps because otherwise it wakes people up if we lose power while we are sleeping.

This feature isn’t that uncommon, but you’re right that it’s not universal. So you definitely want to check the manual before buying if it’s important.

FWIW, mine also offers this feature. (See the manual on page 17.)

Your link makes it a little hard to read.

Funny, because I switched to CyberPower after using APC for years because I couldn’t find a model that allowed you to disable beeping after, yes, hearing about it when the power went out while we were sleeping one night.

I thought about this for a bit and really it will be fine for my Mac mini - it draws 7 watts when it’s idle (which it is most of the time), 100 watts at peak load (which this machine rarely is). I just checked the UPS (it’s hard to get to) - it’s telling me that the load is 10% and the run-time is showing from 49 minutes to 52 minutes. So, this is fine.

Strange. It’s just a PDF.

Edit: I just stripped some of the cruft off of the URL. Maybe it will load better this time.

Edit 2: Looks like a Safari bug. I see the same thing on my system. Loads fine with Firefox and Edge.

It’s definitely by model. I couldn’t disable it on any of the Back-UPS models (their lower-cost units with simulated sine wave output) I’ve owned, but it’s been in all of the Smart-UPS (higher-end units with true sine wave output). Older units were configured via DIP switches, and the current ones are via menus.

I haven’t looked at the Back-UPS models for a while, but it wouldn’t surprise me if it’s not on the lower-end models. Makes no sense, but marketing departments rarely do.

You must have a newer Mini with Apple Silicon - they do draw less power. Mine (a 6-core i7 Intel) never gets that low. And I’m using my UPS to also power my display (which has a CCFL backlight), a backup hard drive and some networking gear.

There’s nothing wrong with a battery that’s just to allow a graceful shutdown. It all depends on your personal requirements. I want to be able to continue to work normally (without the printer, of course) for an hour during an outage. But not everybody wants to do that.

Back in the mid-2000’s, I needed much more. At that time, I was running a 2002 PowerMac G4, a Micron dual Pentium Pro Linux PC and a 17" CRT display. That system would draw about 400W with just the Mac and the display, and around 500-600W if the PC was also running. So my UPS then was also much bigger - a Smart-UPS SUA1000XL with an external battery pack (about $800 then, over $1000 at today’s prices). This gave me about 90 minutes with just the Mac and about 50 minutes with both computers.

When I moved from that CRT to an LCD display and from a PowerMac to an Intel mini, my power requirements dropped way way down to what I have today. And my budget is much happier :slight_smile: .

Speaking of working from the UPS when power is out, how long will it take to charge the UPS enough to handle another outage while working, i.e., a high-risk time of not being able to backup? I assume that there won’t be a full charge but enough to do the job. I also assume the UPS-initiated backup will be a hibernation event since there might be open working files.

That will depend on the specific model. The manual for mine says:

The UPS will charge to 90% capacity in the first three hours of normal operation. Do not expect full battery runtime capability during this initial charge period

As for what macOS does when the UPS switches to battery power will depend on your Energy Saver settings. With macOS Sonoma, it will do a shutdown (not a hibernate) when the configured threshold (time on battery, remaining battery time and/or remaining battery charge) is reached.

But this is on an Intel Mac mini, where hibernate support doesn’t exist. It may be different on a laptop. Of course, a laptop doesn’t need UPS power management - when the UPS battery runs out and the unit powers off, the laptop will just switch to its own battery, which has its own power management settings.

Of course, third-party power management software might be able to do other things.

I’ve used Cyberpower UPS units for years. I live in a post-war building in NYC and power fluctuates are frequent. Macs actually handle voltage fluctuations pretty well, but transients can wipe out your power supply.

Firstly, a pure sine wave UPS is essential. Simulated sine waves will crash your computer, every time. Secondly, a UPS should only be used for powering essential components. Basically, that means the cpu, primary display, router and connected hard drives or SSDs. Connecting a laser printer actually voids the warranty. Thirdly, most UPS batteries are lead acid. They last about two years and must be disposed/recycled properly.

Finally, these units are primarily for brief power outages. Anything longer and the main use is to allow you to save your work before shutting down. If you need more than that, you should buy a new Mackbook.

Late to the game here, but I use UPSes regularly in professional applications. I’m surprised that nobody mentioned an important aspect, which is the type of UPS: Offline, line-interactive, or online. The last is the most effective because it generates completely fresh power from the DC side of the circuit at all times. But also the most expensive. Here’s an article I did for an AV industry magazine with more info:

I will also add that my experience over years with APC has been poor, I won’t use them. I spec Eaton for my clients’ systems. I’ve had good experience with Cyberpower but only in limited use. A good UPS will run for ages if the batteries are replaced. I’m using a line-interactive model from MGE (now Eaton) that’s at least 15 years old.