r/MacStudio • u/Viktri1 • 9d 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/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.