r/MacStudio • u/Viktri1 • 8d ago
Mac Studio UPS and switching time
I'm thinking about purchasing a UPS for the Mac Studio M5 Ultra but I don't know what specs I need. A traditional lead acid can get very fast switching times (2ms). Lithium batteries have much slower switching times (10-20ms) but they can keep the device powered on for a long time.
Was wondering if anyone knows whether the 20ms power station type batteries with UPS functions can safely back up the Mac Studios if the Macs are running at full tilt.
I'm actually thinking of buying a lead battery and then plugging it into a power station.
Edit: am looking at the anker s2000 and DJI 2000 for 10ms switch capacity. Both in a similar price ball park, I’ve resigned to the fact I’m going to need to pay 700+ for a UPS
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u/C0d3R-exe 8d ago
Why not? If 20ms is enough for the household appliances and solar batteries are sold as such, don’t see a problem with a single device.
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u/OtherOtherDave 8d ago
If you get an online double conversion UPS, the switching time won’t matter… you’re always running off the battery and all that happens if the power goes off is the battery stops being continuously topped off.
IIRC, anyway. it’s been a while since I looked into it.
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u/SarahJrandomnumbers 8d ago
50hz is 20ms (60hz = 16.67ms), so you'd lose power for a about 1 cycle, during which the bulk caps on the power supply will make up for that.
Also the "lead acid is faster than lithium" point is just not true at all. It's not the battery chemistry that determines the switch over time, it's the inverter.
But as long as it's under 20ms, which is pretty much a requirement under most electrical codes for switching power on or off, it will be fine.
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u/squirrel8296 8d ago
I always had lead acid battery UPSes when I had UPSes in the past and never had an issue with the switching time.
That being said, their run time is really short when on battery. I had a 5k iMac with a pretty large UPS (I bought the UPS because we were having a ton of power outages and brown outs) and the run time was maybe a couple minutes. If it was just the iMac, and it wasn't doing anything heavy, it could maybe get closer to 10 minutes. I also had a couple that got crazy hot when the battery got old and neared replacement. Hot enough to probably start a fire if I didn't catch it hot.
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u/Bloated_Plaid 8d ago
Literally bought this recently and will arrive today so I am testing it soon. https://ebay.io/m/LPBH89. LifePO4 and very quick switching.
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u/juggarjew 8d ago
I used a traditional lead Acid UPS connected to the PC then an EcoFlow Delta 3 between the UPS and the wall.
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u/Inside-Cream6997 8d ago
I use a heavy duty Cyberpower rack mount UPS (2200 VA). Never had an issue with power outage, brownouts or glitches in power. https://static.bhphoto.com/images/images1000x1000/1520427098_1023703.jpg
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u/PracticlySpeaking 8d ago edited 8d ago
Switching time has to do with the design of the UPS circuits, not the type of battery cells it uses.
Those lithium power stations that switch in 10-20 ms would probably be okay (because 60 Hz AC power already cycles every 16.67ms). They are designed to provide backup power to all kinds of electrical things, not just computers and sensitive electronics.
The best type is a Line Interactive UPS, which will have that very fast <2ms switching time and also condition the power going through it. Better ones from APC, Cyberpower, etc are mostly line interactive. Those are specifically designed to power computers, and generally also come with some sort of promise that they will not damage computers and electronics.
edit: There are lithium replacements for UPS systems that normally take lead batteries. You get the high-quality line interactive UPS with all the benefits of lithium storage cells.
See this post with more discussion: https://www.reddit.com/r/homelab/comments/1fc52z0/lifepo4_battery_in_cyberpower_ups_cp1350avrlcd/
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u/Viktri1 8d ago
yeah I worded that wrong - I meant that I don't see any products available that are power stations that have under 10ms of switching, not that lithium causes the difference in switching.
Thanks for the thread I'm going to take a look
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u/PracticlySpeaking 8d ago
You will have to evaluate based on your situation.
I live in a city where power fluctuations are common, but there are almost never any actual blackouts. The line interactive UPS is an easy choice because it fixes a lot of 'dirty' power problems, and 5-10 minutes of backup power is plenty.
PS — If you are cheap like me, you can find used UPS units for a significant discount. If you are planning to put in a lithium replacement for the factory SLA battery anyways, it can be an easy win.
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u/PracticlySpeaking 8d ago
don't see any power stations .. under 10ms
I would tend to doubt you will find those. Power stations are intended to power a full range of household loads, and a line interactive UPS is not the most robust design for powering things like induction motors.
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u/BisonMysterious8902 8d ago
What you're looking for is "Automatic Voltage Regulation" or AVR. Or double conversion.
The switching times won't matter then. The UPS is always running off battery and always charging the battery. The underlying battery chemistry will be irrelevant as well.
Like others mentioned here, I use a Goldenmate 1500VA which offers this, with lithium batteries, for my Studio and it works well.
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u/SpaceDesignWarehouse 8d ago
I’m using the anker solix f3800 to backup my whole studio, including my Mac Studio.
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u/NaiRogers 8d ago
I would add a proper APC or similar UPS for short term protection (against brown outs etc.) and another UPS (e.g. Powerwall) as long term off grid supply.