3D Printer + UPS = Magic & UPS model recommendations list

nicktoca · March 4, 2026, 2:44am

I’m opening a discussion to share my findings with a UPS (battery backup). I’m an IT professional with 25 years experience in networks 🖧. I have a UPS on my home network and another for my TV. When the power goes out my WiFi lasts for 3 hours and 1 hour of TV via the UPS’s . They are APC Smart UPS 1000va which is actually 600W despite the misleading 1000 in the model #. (Please see my recommended list at the bottom if that’s all your looking for, but I’d recommend reading all of this.)

Because the P2S has a huge power draw when warming up (about 15-30 seconds), the UPS light flashes red and an error on its screen says “power overload” . Once that phase passes however it then shows “RunTime 1.5hrs and as much as 2.5 hrs” which means if the power goes out it will continue to print for 1.5hrs - 2.5hrs .

So the theory and conclusion: Even though I get the power overload error at the beginning, it doesn’t matter because nothing is printing at that time anyway. What matters is while it is printing if the power goes out, the power won’t simply go off and stop printing or much worse cause a clumping disaster . It will give time to gracefully stop the print or allow it to finish if it’s close to being completed ██████ 100%.

For now, I removed my UPS from my TV to the P2S printer and will replace the TV UPS soon. I’m lucky because I get these for free from work . Clients replace theirs when the battery dies and I then buy a replacement battery for $30-50 on Amazon and good as new and very easy to swap the battery. Not ideal for production networks, but fine for my house .

For everyone else who does not get these for free here is the recommended UPS units and approximate costs in CAD$ from Amazon. The ones I have are super expensive, but I believe a cheaper alternative should also do a good job :

Maximum (no budget) :

APC Smart ups 1500 (1000w) $770
CyberPower CP1500PFCRM2U PFC (1000w) $430
APC Smart ups 1000 (600w) $600 I have this one

Budget Friendly :

CyberPower CP1500 (1000w) $290
CyberPower CP1500PFCRM2U PFC (1000w) $430
APC UPS 1500VA (900w) $315

Since I don’t have any experience with the budget friendly models on 3d printers I have to say here that at the heat up phase these may start beeping a very loud and annoying sound while it reads power overload. You should be able to mute if you hold the mute button and hopefully never have to hear it again (if someone has tested this please post your findings). I have used these budget UPS’s extensively at work, but not the power overload part because I put the smallest load when backing up a network so it stays alive longer. ie. Modem, Firewall, Switch, WiFi AP

For APC brand (the only brand I have every used in production and at home–although I feel CyberPower may actually be better):

To get the screen to stay on, long click the “menu” button until it beeps once. Then click menu button again (quick clicks) to cycle the menus until you find the display that says “minutes during power failure” and it should then remain on this screen so you can see live how much time it will last and more importantly during an actual power failure how much time you have left before it powers off.

Hope this helps some good friends and fellow print enthusiasts out there and thanks for reading. Please add any experience you have in here to also help our friends .

MaxThreeD · March 4, 2026, 3:08am

Do you happen to know if there are any longer-term consequences to routinely overloading a UPS like that? Assuming something decent quality like mid/higher end APC or TrippLite.

I need a UPS that only lasts < 1 minute (have an automatic generator), but that initial power draw is a b**** (H2C). I guess if power-loss-recovery really works then I’m OK, but I wouldn’t mind not testing that feature if there was a practical way w/out spending another printer’s worth on a UPS.

Thanks,
-Max

nicktoca · March 4, 2026, 3:18am

I don’t think there is any issue with the overload. It’s likely they battery does not even get used for the overload. For example, I originally had this on a bitcoin miner that used way more than the battery capacity. It would just beep constantly, but the miner still worked. So it likely bypassed the ups altogether if it goes to overload. If I were to recommend something though, I’d suggest that $290 cyberpower with 1000w. I doubt even the H series reaches 1000W draw. Also, the batteries are cheap so if it kills the battery it’s $30 to replace. The unit is the expensive part. But wait, I just checked the H2C initial power draw–huge: The Bambu Lab H2C has a high initial power surge during startup, reaching peak consumption of 1,792W (220V) or 1,267W-1250W (110V). This spike, caused by rapid heating of the bed and nozzle, lasts only a few seconds, with typical printing power settling around 200W-298W depending on material and voltage.

My Conclusion. Get one from Amazon, test it and return it if does not work out well.

MaxThreeD · March 4, 2026, 3:27am

Exactly I’m sure the overload protection doesn’t involve the battery at all (it shouldn’t even be using the battery at that point unless mains are already out), but I’d hate to ruin a $$$ UPS because the overload circuit isn’t designed for repeated abuse.

Also, exactly. Some users here have reported even higher initial draw. The 300W I could even piggy-back onto a UPS already in the printer room, but yea that initial draw… whew.

-Max

Bratling · March 4, 2026, 3:41am

Depends on the type of UPS:

Offline UPS - normally power runs through it directly to its load. When external power drops, a relay switches to running the inverter off the battery. Slowest react time.
Line interactive - actively manages input to provide a cleaner output to the load. Inverter is always in the loop, rather than being activated at need. This lets it switch power much faster, often within a handful of milliseconds.
Online - power always runs “through” the battery. External AC power is converted to DC and fed to the battery. The battery outputs DC to an inverter which converts it to AC for the load. There is no switching time because the power path never changes. Best type, but wears out batteries regularly; schedule replacements every year or two.

Another thing to look for is true sine wave output. Most affordable UPSes provide either square wave (ugh) or step-sine (also ugh but less so). If your protected hardware has AC motors, those waveforms will risk damaging them. Probably not a problem for a 3d printer and it’s DC servo motors.

All seems a bit silly to me. I’ve had power fail during a print. My P1S started right back up, resumed the print and finished flawlessly. But I suppose a UPS is at least good protection for the machine, so if it makes you feel better to have an orderly shutdown, why not?

(I’m that idiot with a rack mount online UPS running my home network, servers and WiFi. Power may go out but our internet does not!)

nicktoca · March 4, 2026, 4:06am

I’m the same. 3 hours wifi when power goes out. I don’t have any eth jacks. House too old and a pain in the butt to wire. Happy your printer worked after the power outage. Nice. Thanks for feedback and input Bratling. Informative and helpful . Appreciate it.

MaxThreeD · March 4, 2026, 4:27am

Good point/reminder on different UPS types, thanks. I usually run LI with true sine outs for the gear I’d like to last a while (most of which just converts it “back” to DC… LOL), and the cheaper “home” square/faked units for less important stuff. But honestly I’m not sure I’ve ever seen any practical difference (after ~3 decades of both “IT level” and home use).

What I have seen is cheap-ish plastic UPSs literally melt when used continuously near their limits just on mains power (not even on battery)… so no thanks on those for me, especially with talk of overloading.

Good to hear about power recovery working (not an H2C, but still!). I just dropped a buck seventy for a heavy duty racked 20A TrippLite surge protector/strip, so at least the printer isn’t going direct to the mains as much. Gonna stick with that for now!

-Max

Bratling · March 4, 2026, 2:04pm

Say, one more note: UPS batteries wear out but not the rest of them. This means you can often buy perfectly good high end ones cheaply, replace the batteries and be back in business. That’s how I scored a high end APC for my network

Same. I know that square wave bugs the ■■■■ out of me because it’s harsher on the equipment and just feels like corner cutting… but does it really affect anything I have plugged in? Probably not. Like you I use cheaper ones for my pc and better ones for infrastructure.

lkraus · March 4, 2026, 4:13pm

Fortunately, the switched power supplies used in our printers and computers don’t care about the wave shape.

NoH · March 4, 2026, 4:56pm

As noted above, the sealed lead acid batteries wear out fairly quickly in most UPSs. I have been using a new one at work. These have a Lithium Iron Phosphate battery in them. This is the safe, long lasting lithium type that doesn’t catch fire and lasts decades over thousands of cycles. This brand also has more Wh of battery storage on board than most lead acid types. (Especially when you start to factor in high C rates from the lead acid batteries that decimate their actual capacity.) However, I don’t have any of the larger ones to try at home. But this should be worth considering, if you are buying new.

The smallest one would not be able to do the bed heating power level, but might bypass for that period. Don’t know. Could possibly test this. Runs about $210, but often has coupons to drop ~$20. Definitely a standby model, but switches quick enough for computers and network gear.

This is the first one that matches the seen power in the other thread of about 1000 watts. Line interactive, speced as pure sine wave. Approximately $370. Approximately 1.5 to maybe 2 hours of printing time, based on the ~150 watts typical printing seen in the other thread.

There are two other models with higher power. This one gives some headroom on the wattage output, but doesn’t increase the battery size at all. So the extra $100 is just headroom.

Last one increase the UPS size and the battery size. So this one would be closer to 3 estimated hours of runtime.

nicktoca · March 5, 2026, 3:44am

This is great NoH. If you can now buy lithium for virtually the same price, this is a good way to go for users. Haven’t heard of that brand, but seems they are ahead of APC and CyberPower and will likely take some of their market share before the big brands start using lithium ion. Everything else uses lithium now so why not UPS. Thanks for sharing and good find. I like it!

MaxThreeD · March 5, 2026, 4:09am

Hmm, reports of reversed polarity and open grounds, no actual certification listings, non-replaceable batteries (AFAICT), heavier than lead-acid… yea I dunno. Call me conservative. The (relatively) inexpensive lead-acid batteries typically last me many years already (how often do you replace your car battery which has a much more stressful life?), and actually are better at handling loads than anything lithium based (“C” rating).

-M

NoH · March 5, 2026, 3:15pm

Per the reviews and markings, I did read the reviews on the bigger models and see those do have problems in their review. I can’t say much about that, as I haven’t experienced them. I only have about a dozen of the 800 watt models. And looking at APC and Cyberpower, their 1 star ratings are a similar percentage, so it doesn’t stand out the same way. Guess just make sure to test it within the return window. As for markings, the units I have do have regulatory markings. However, one would have to do research as to if they are self certified or lab certified. The last marking is hard to read. It is “IEC 62040”.

I’ll go on a rant on lead acid batteries soon.

R3d-Five · March 5, 2026, 3:30pm

It won’t. Works fine for a P1S but will not hold up to the H series. Cannot comment on P2S but I would imagine for fast bed heat it wouldn’t, or at least complain about it.

The rest of the Goldenmate line is as dependable but like you mention, more butt to back it up.

There are many of us that just want to get past the hurdle of the bed warmup at startup. Backup is nice but dropping a breaker when starting up get’s old. I have no care for a backup battery protector as our printers have resume and they do it very well. I just want to keep my little bench up and running without damaging anything in the meantime.

My .02 is that a battery back up is all but (in above case) useless in a restoring or keeping a print running sort of way. It’s been awhile since I’ve seen a printer struggle with resuming.
Even for a resin printer they’re only good for the occasional drop that are quick. They have no resume.

I think if you need to do you, fine. But let’s be real, aside from surge protection there really isn’t a need for keeping the power to it if the power goes off.

The only testament I can give is the one 600 (used to be one) has been running for 3 years now with no issues, and the 800 has been running nearly a year without issues as well. After that I can’t comment. I’m happy enough with them though.

mariomart · March 6, 2026, 2:53am

I have the P2S with AMS 2 Pro and AMS-HT all connected to a Cyberpower 2200VA/1320W VALUE2200ELCD UPS. I am located in Australia which uses a 240v AC 50Hz power grid. I have tested this UPS by printing ABS (bed temperature 90ºC) through the AMS 2 Pro whilst also using the AMS-HT to dry ABS at 80ºC simultaneously. I watched the load readings on the UPS and the absolute maximum that it registered was 97% load with zero overload beeping. The 97% load was only present for the first 30 to 60 seconds whilst the bed was heating, and then the load varied between 17% and 47% during the initial filament purging and auto leveling pre-print phase, and then sort of hovered around 10% load during the actual print.

I hope this real world use information helps. Cheers

user_254122797 · March 6, 2026, 1:57pm

I have worked in IT 30+ years with 24 as a network engineer. APC is the best IMO. I use Smart-Ups as you can monitor/manage them though you network. I have a 1500 on my printer. I got mine on Ebay $220. It didn’t come with batteries which I prefer. Even if the listing says new batteries they will be the cheapest with usually don’t make it more than one year. I use only Interstate batteries. Stay away from Tripp Lite UPS.

PerceyBlakeny · March 7, 2026, 8:47pm

The more demand put on a battery, the more that watt thing rears its head. That is, the more heat is generated inside the battery, whether lead-acid or other.

That something goes on working when more is taken from it than it is designed to give does not mean damage isn’t being done. Cold isn’t the only thing that affects battery performance.

In the end, performing on the side of caution, with few exceptions is the best plan. That may mean a bigger package, or doing the parallel add thing (another temporary supply).

Here is just one result from a Net search:

“[H]igh heat significantly damages lead-acid batteries, acting as their primary enemy by accelerating internal chemical reactions, reducing lifespan, and causing water evaporation.

The battery’s lifespan can be cut by 50%.

Key Effects of Heat on Lead-Acid Batteries:

Accelerated Corrosion: High temperatures speed up the corrosion of internal lead grids, leading to premature failure.
Fluid Evaporation: Heat causes the water in the electrolyte solution to evaporate, reducing capacity and damaging internal components.
Sulfation and Self-Discharge: Excessive heat increases the rate of lead sulfate crystal formation (sulfation) on electrodes, reducing performance.
Thermal Runaway: Extreme heat can cause internal damage that, in severe cases, leads to uncontrollable rising temperatures and failure.

PerceyBlakeny · March 7, 2026, 8:52pm

SNORT. Love mine. It keeps the electric fence going when Grand Coulee Dam is down.

jym.mails · March 8, 2026, 12:24pm

Hi,

I have a P1S and I am using a river 3 plus from Ecoflow and I am really happy with .this UPS

MikeB3 · March 10, 2026, 11:54am

I’ve been running the large goldenmate unit on my H2D since May of last year and have had no problems to date. The maximum power output is right at the absolute limit of the printer though. During startup of a print job it will cause the ups to alarm for a few seconds using full power mode. I have not had a chance to try the new firmware with the low power startup setting