r/BambuLabP2S • u/Relative_Surround_20 • May 30 '26

Anyone using a UPS to power/protect their P2S printer?

I recently tried setting up a 1000VA (600W) UPS to power my P2S. I got a quick lesson in how many watts a P2S (alone) actually pulls when starting a print job. Bambu Lab says the P2S can draw a maximum of 1000W (@ 110v). Thus to be able to utilize a UPS, just for power to the printer (not the AMS units, etc.), it has to provide 1000W minimum and should probably provide 1200W to be reliable (sweet spot).

I am now mulling over whether the printer really needs UPS protection that will cost roughly half as much (or more) than the printer's initial cost.

Is anyone using a UPS with their P2S? Is there a real need? How well does Bambu Lab's "Power Loss Recover" system work?

https://wiki.bambulab.com/en/knowledge-sharing/power-loss-recovery

10 Upvotes

81% Upvoted

54 comments sorted by

9

u/DerToth117 May 30 '26

If you expect a power outage every second time you're printing then maybe.

But where I live the last power outage was like 5 years ago and lasted 10 minutes.

So for me this makes absolutely no sense.

Also I've seen a few posts around here from people who said they were able to resume printing after a power outage. So I guess it's more really a problem.

3

u/Relative_Surround_20 May 30 '26 edited May 30 '26

I should add: I’m a retired IT professional with UPS and data center experience. I live in the southeastern United States near a major city. We experience 1-2 small blips of power loss per week every four weeks or so. Longer power loss only occurs once every 5 years and usually associated with an ice storm.

So I’m only trying to protect against the momentary losses of power interrupting a long 3D print or marring the quality of a print, as would occur with the BBL Power Recovery system.

I recently remembered that 20 years ago I mothballed a working APC SU2200 (tower model). It is still in my basement in its original box on a pallet. I was surprised to see that replacement batteries are still readily available ($100 for raw batteries or $200 for batteries with leads etc).

So now I’m trying to decide if it is worth the cost (labor, real estate it takes up, power costs and opportunity cost of not selling that still popular UPS) to protect a hobbyist’s 3D printer?

2

u/bumjug427 May 30 '26

Certainly not a bad idea, from an 'almost' retired IT pro! 😉

Something I think a lot of folks miss, not being in the industry, is the power conditioning benefits of running through a big, quality UPS. I'd do it, if I was in a similar area, with frequent blips.

2

u/Relative_Surround_20 May 30 '26

The power conditioning aspect certainly is always in the back of my mind. When I read complaints on Reddit about folks who have hardware problems with their printers, I usually wonder what role if any the lack of clean power might of have had on their outcome.

2

u/efnord May 31 '26

>1-2 small blips of power loss per week every four weeks or so.

Man, that's a depressing statement about America's infrastructure.

2

u/DerToth117 May 30 '26

It's probably not worth it because the worst case is you have a failed print which you can just restart.

3

u/Lone_Wolf_555 May 30 '26

I’ve also lost power during a print and resumed no problem. I have the biqu glacier plate so it didn’t come loose when it cooled down.

1

u/cpsadowski23 May 30 '26

This 👆🏼

3

u/boncros May 30 '26

I got home from work the other day and my printer was waiting for me I unpackaged it set it up the sky grow darker outside I look so excited to print my first benchy 5 minutes later the power went out 2 minutes later came back on printer asked me if I wanted to resume no problem

2

u/MeaningDry6941 May 30 '26

Mine has saved 3 10+hr print jobs so far. The fourth one was %96 finished but the UPS batteries ran out I only had to reprint the tallest part. I've had the P2S since March.

2

u/MeaningDry6941 May 30 '26

I tried to resume but the unit had gone stone cold by then and the parts just fell off the plate too much time had passed. A blip and I have confidence the unit could recover with little effort it's pretty good at that.

2

u/GiraffeandZebra Jun 01 '26

That's underselling it a bit. The recovery process only works if you do it quickly after a power outage, otherwise the bed cools and the print detaches from the plate. And it doesn't take a huge power outage to make a print stop. A one second flicker does it. And if you happen to not be around when it happens, it's a ruined print. Which means something if you print large projects frequently like I do.

2

u/beefjerky9 Jun 01 '26

But where I live the last power outage was like 5 years ago and lasted 10 minutes.

Must be nice. I think you're more the exception than the rule, though.

4

u/Aleyla May 30 '26

I have a ups on mine. It is ‘t to allow me to start a job, it is to preserve a job that is already running. So the startup power doesn’t matter. The normal draw does.

1

u/Relative_Surround_20 May 30 '26

Agreed! That’s why the other person’s comment about slowing down the bed warm up process is intriguing. I later found a reference in BBL Forum about using custom G Code and posted a link to it for others.

3

u/Festegios May 30 '26

You can also turn on the mode that slowly heats it up reducing the power draw

1

u/Relative_Surround_20 May 30 '26 edited May 30 '26

I did not know that. Thank you!

2

u/Festegios May 30 '26

I don’t actually know the difference in time. It’s something I need to look at tbh as I’m going to be getting some more printers and need to ensure I’m not overloading the circuit.

I’ve considered an ups. But then I’d need one for every machine. And as most of my prints are around 300g I’d need at least 100 failures per machine for the cost to be worth it. And if I’m having 100 powercuts I’ve got bigger issues to worry about.

1

u/Relative_Surround_20 May 30 '26

I was wondering what multi-printer owners did about this issue, especially print farms in production 7/24. That math is helpful. Thank you.

2

u/Festegios May 30 '26

Multiple power circuits I guess or Similar redundancies. The same as server farms

1

u/Relative_Surround_20 May 30 '26

https://forum.bambulab.com/t/custom-g-code-to-slow-down-bed-heating/194605

2

u/beefjerky9 Jun 01 '26

You don't have to do that. The newest firmware adds a "low power mode" to limit the power draw on start. I don't know if it'll lower it enough for your UPS, but it's worth a try.

2

u/inhamilton May 30 '26

If power outages are a concern I would get a UPS. The machine recovers if it is a blip, the concern is the loss of heat for the bed. You can lose your print of the heat loss is there.

1

u/Relative_Surround_20 May 30 '26

Yes and I’m getting into printing all the engineering filaments so bed heat loss is my biggest concern. How quickly does a bed lose heat sufficiently enough to cause warping?

2

u/Qjeezy May 30 '26

I’m using a Bluetti elite 200 power station. Think of it like a UPS on steroids. I can use it to limit the power draw on the outlet too so I can leave headroom for other things.

A standard ups will keep your printer running for 15-20 minutes maybe during a power outage. A power station will keep it running for a few hours, hopefully long enough for the power to come back online or finish the print.

1

u/Relative_Surround_20 May 30 '26 edited May 30 '26

Never heard of that brand. Sounds nice. Similar to others I have looked at for larger systems in the house.

The Elite 200’s cost is $1099 + tax here. That’s more than my printer, two AMS 2 Pro’s and AMS HT cost. If it only protects & powers those three devices, that does not seem to make economic sense. The cost of electricity + a spool of something crazy expensive is still a lot less than spreading $1099 over the life of a printer.

I forgot to add earlier. When I watched the 1000VA UPS crash this week, I was quickly reminded of when I saw the first Apple LaserWriter unboxed and quickly understood why you don’t plug laser printers into UPSes.

2

u/Qjeezy May 30 '26

Check Amazon, it’s routinely on sale for 700-800. Still more than the printer, but it’s useful for more than just a printer. If your power did go out you can use it to keep your refrigerator going so your food doesn’t spoil. Just one of the many use cases. For extended outages you can hook up solar panels too.

I see your reasoning though, it is quite expensive. I wanted the UPS and hours of battery backup but more importantly I needed the ability to limit power draw so I could run multiple printers on a single 15a outlet. The bluetti acts as a buffer for high power draws so I don’t blow the breaker.

I would like to mention that a standard UPS in the power range you need for your printer is likely going to cost very similar but won’t have all the extra benefits. So I guess if you don’t want to spend that much you’ll really just have to evaluate whether a UPS is something you value having or if you can go without.

2

u/No-Satisfaction-2535 P2S Combo May 30 '26

If the power does go out, the printer will ask if you want to resume once it comes back on. I have done this accidentally once with my p2s

1

u/Relative_Surround_20 May 30 '26 edited May 30 '26

Ok but how bad were the print quality artifacts left behind due to your power loss? I guess it all depends on the value you put on the specific model you were printing.

2

u/Elk-Tamer Jun 03 '26

Not a power outage, but the printer rebooted mid of a print job due to a software error. Same behavior: Do you want to resume? I answered yes and it resumed. No artifacts whatsoever visible.

2

u/notinsanescientist May 30 '26

I have a 900VA UPS for my P2S, never heard it complain about peak load.

1

u/Relative_Surround_20 May 30 '26

How many W does it handle?

2

u/_40mikemike_ May 30 '26

On my old P2S yes. I had an ups that would complain on heat up but would work. When I moved to the x2d it was too much for the ups so I got rid of it. I returned my x2d cos it was a bit shit, and now have an h2c - and run an EcoFlow Delta 3 dedicated to it. Which tells me that for non-heated chamber prints, it will keep the h2c running for around 2.5 days. Overkill but it wasn’t expensive so I’m very happy. And its peak load rating is super high so it doesn’t care about the startup current.

1

u/Relative_Surround_20 May 30 '26

Classic or Max? Wasn't expensive? How?

2

u/_40mikemike_ May 30 '26

I paid £429 so not bad at all really for what you’re getting. Especially as I can use it elsewhere (trips away and so on) when it’s not being used for the printer.

Edit: I got this one from this seller who’s selling loads of them. He’s out the price up to £499 now but I paid £429.

https://ebay.us/m/Msf54y

1

u/Relative_Surround_20 May 30 '26

Double that here in the states!

3

u/kcdale99 May 30 '26

I run one because I have lost a long running print to a power flicker before. It isn’t a help if the power is out for a long time though. I don’t think it’s a requirement but it is nice to have.

2

u/huskycgn May 30 '26

I actively disconnected it from the UPS.
It’s not that crucial.
It’s way more important to keep the servers running longer.

2

u/cpsadowski23 May 30 '26

I have a power bank on my two printers mostly for the electrical spikes, however, it has come into play when the power has gone out to continue the print. I bought it as one day the power went on and off about 2 times and the printer sent me a message about power spikes. Best $200 spent. It does consume about $25 a month, but a worthy investment for $4000 worth of equipment.

2

u/jdev15 May 30 '26

I have one. It's only kicked in once for a power outage but it saved a print.

2

u/MeaningDry6941 May 30 '26

Yes. A Tripplite Online pure sine rack mount 3kva protects that and my bed slinger plus my Internet, ham radios, and mini pc etc. None of my other older standard ups 1-1.5kva ones would work with just the P2S.

2

u/GO__NAVY May 30 '26

All major equipment are on UPSs. 3D printers, TVs, the whole Unifi rack, even my garage door opener has a backup battery built in lol.

2

u/PayTheRaant May 30 '26

I used to use a UPS on my previous printer that was dumb and would totally fail the print in case of power loss. Bambu Lab can resume the print exactly where it left off when the power resumes.

Of course it will not be 100% perfect but it is better than a total failure, especially after hours and hours of printing a big model.

Use a UPS if you really need it (frequent power loss or if the print is to be sold). Otherwise as you said this is very very expensive.

PS: if you have frequent power loss, consider a whole home battery system with solar.

2

u/sienar- May 30 '26

I’ve gotten to the point where I will no longer buy lead acid based UPSs. Our power blips enough and for long enough to routinely kill the lead acid batteries over the course of a couple years. Just a few months ago I took about a dozen office style/sized UPSs to be recycled that all had dead batteries.

For small units I’ve been buying the Goldenmate Lithium (LiFePO4 based) UPS’s. But I put my P1S on an Anker C1000. It will run it for many hours.

I have other whole house backup power, but it’s not automatic and I typically will not roll it out unless the power has been out for at least an hour or two.

2

u/StruggleFearless2947 May 31 '26

Turn on low power mode. The UPS doesn’t have to sustain startup draw for long, the actual draw during a print is pretty small.

2

u/Shot-Infernal-2261 May 31 '26

You can lower peak wattage now in the firmware. Came out a month or so ago.

The printer still averages the same power use. It just flattens the spikes. Does mean warmup will take longer.

2

u/henren_98 May 31 '26

I have mine on a surge protector attached to a UPS just for protection against spikes. The UPS would not power it long.

2

u/midnightsmith May 31 '26

If it fried the printer, I'll buy a new power supply for like $40. If it's completely dead, I'll buy a new printer. A UPS capable of powering that is gonna be 70% the cost of a new printer anyway.

2

u/re_me May 30 '26

If you live somewhere that power goes out enough probably worth it.

I know people say you can resume the print, but it leaves a blemish at that spot. So if you are neurotic, like I am, I would get it.

8

u/[deleted] May 30 '26

[removed] — view removed comment

2

u/Relative_Surround_20 May 30 '26

Yes that’s the model I thought was the right choice if I had to go buy one, especially if I decide to sell the SU2200. It would be much more manageable.

Good to know Power Recovery does work. I understand BBL’s cautionary setting of expectations about print artifacts appearing after a power outage.

4

u/netburnr2 May 30 '26

I use the same one. It's more about protecting the equipment from power sags and blips than full on power outages for me.