Best UPS for H2D

Bambu Lab H2 Series
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At least initially I’m using the DJI 1000, which can deliver up to 2200w continuous. It was $379 on amazon from Black Friday through Christmas, though it has bounced up since then. It can be limited to not charge faster than 600w.

It’s not truly ideal though, as I think it’s not likely to engage unless the mains voltage to it fails, which is what I want to avoid. So, for my purposes, I disconnect it from mains while heating the H2D to temperature, then reconnect. This is seamless, and at that point, the circuit has plenty of headroom.

More ideal would be a double conversion power source, where the input watts can also be rate limited. This way the H2D would only draw upon battery power at all times, and the battery just acts as a buffer during the initial power up of the H2D to temperature.

In general, the batteries on a double conversion type probably doesn’t last as long as the kind that switches over only when needed. However, given the large number of charge-discharge cycles most LiFePO4 batteries now claim, that may not matter from a practical standpoint. More than likely most quality LiFePO4 batteries, especially if of the EV type and so built to automotive standards, will age out before they wear out, at least for anything I’m likely to use them for.

Of course, all this may be overkill. I’m just being extra cautious at the beginning, until after I collect my own measurements. Thus far, according to my emporia smart plug energy monitor, H2D draws a peak of 1469 watts while running the calibration from the console. That’s higher than the 1320w peak for 110v in the H2D spec sheet:

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My 1469w measurement was with no AMS connected. This peak lasted for less than 30 seconds. Emporia states that their smart plug energy monitor accuracy is within ±2% of actual energy usage. Go figure. It probably pulls more than the rated power since my mains voltage is probably closer to 115 or 120vac than to 110.

Regardless, the DJI has enough amp hours that it will sail through just about any non-catastrophic blackout without pausing for even a moment, which is nice belt and suspenders.

Anyone else have a preferred UPS or other power source that they like to use for H2D?

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Yeah, I was using a 1500w UPS from like 20 years ago and the cable was getting pretty… melty. I would certainly recommend a newer +2kw on 120v at least. This thing peaks in power similarly to my welder. I don’t have a UPS anywhere near that level.

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The DJI 1000 doesn’t appear to be a true UPS, however. It says to unplug it when it’s charged so it would appear to require a fair bit of manual intervention. Although it could be used with a source transfer switch, I suppose, like the Eaton Pulsar STS line (but the 120V version seems to max out at 1400W, which isn’t enough).

I’ve been investigating UPS options, and there are a lot more options with 240V equipment, but you can’t get a 240V H2D in the US. Finding a UPS that can handle 1500W is pricey. Finding one that isn’t meant for a server room (i.e., reasonably quiet) is even harder.

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Does it have a solar input? I don’t know how these work, but if you feed it 500w solar can’t you still draw 1000w ac out?

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Good point. Unlike most power stations DJI requires an add-on dongle to charge from solar or DC, but with that add-on you’re exactly right. Yes, that should do the business. And it should be able to draw the full 2200w output continuous–not that it would ever need to go that high–since it would be pulling from the battery rather than a pass-through. With the 12v adapter, it can charge at up to 1000w (meant for charging from a direct connect car battery with the engine running, without stalling the engine, but any sufficient DC power source should do just as well), which I’m fairly sure is well above whatever worst-case average the H2D might ever draw. The 1000w adapter is effectively like an MPPT controller: it will take whatever power it can without crashing the input DC voltage below some minimum threshold. So, if I wanted to charge it at a lower rate, I should be able to simply supply it with less power, within reasonable limits, and it will adapt accordingly.

Usefull workaround! Effectively converts my DJI into a double conversion topology, giving the option for the best of both worlds. In so doing, it eliminates any switchover time as well. That being the case, whether it’s advertised as UPS or not, in this configuration I don’t see why it wouldn’t qualify as one, at least for this application.

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Just now started my first print from the slicer, and initial power draw is 1575w according to my emporia smart plug energy monitor, maybe (?) because I increased the heated bed temperature to 70C from the prior default of 55C. Go figure. I wonder if there are settings which will drive the initial power draw even higher?

So far I have adequate headroom as long as I’m not running any other high current draws during that roughly 30 second time period. Most often I’ll probably run from a UPS anyway, though, given its other advantages, and that will render it moot.

Maybe someone with a kill-a-watt meter, or similar, will want to confirm and post their finding?

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12V 1000W is a very thick cable. Doesn’t it have a higher solar input voltage?

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Good point. Yes, looks as though it can accept an input voltage anywhere in the range from 12-45v:

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The full device listing itself is: Buy DJI Power 1kW Super Fast Car Charger - DJI Store

I bought one purely for emergency backup purposes, and it’s still sitting in its unopened box. I’ve not even tried it yet, but maybe now I have a reason to.

I think it may be at least marginally better than just a brainless boost converter that will try to pull 1000w from anything it’s connected to, even if it means bringing the power source to its knees. I say that because not all car alternators can provide that kind of continuous wattage without overheating and burning up in the process, and it’s presumably designed to avoid that kind of catastrophic outcome. Ecoflow was the first to market with an 800w version, and not long afterward others, like DJI, followed with what I presume are similar offerings.

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I’m not yet 100% sure, but I think I may have found a far simpler way to force my DJI 1000 into running a double conversion mode from AC power. Normally, apparently by design, the DJI will just pass-through AC mains power and only cut-over to battery powered inverter mode if there’s a blackout (or perhaps a brownout, though I haven’t tested for that). However, the DJI also has a feature whereby you can specify the maximum amount you want the batteries charged to. For instance, I set mine to charging the LiFePO4 internal batteries to 80% of their maximum charge capacity, on the theory that not fully charging them will increase the battery’s lifespan.

In this configuration I had thought it would charge to 80% while passing through AC mains voltage, as before. However, that appears to not be what actually happens. Based on the heat of the DJI 1000 power station, it appears to be running the inverter off battery power continuously, all while AC mains keeps the batteries topped-off at 80% of their maximum charge. Because you can also limit the DJI 1000 to a maximum charge rate of 600w, I take this to mean that the AC line feeding the DJI 1000 should not see more than a 600w AC load, all while the DJI 1000 can supply up to 2200 watts continuous from its battery to its inverter, and then directly from there to the H2D. :sunglasses:

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Funny I was thinking about using my EcoFlow Delta 3 that I use for camping, for the same purpose. It can do 1800w sustained, so it should be good for this task, and I can set the charging to 800w, so it’s only ever pulling that much from the wall.

It’s also rated for 4000 cycles @80%, so it should last like 10 years before wearing out(in theory).

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yeah, was considering my delta pro also. im not sure if it is fast enough to switch from power to battery for the h2d though. when i built my office i put each wall on a separate 20a breaker just to divide up load. definitely plan on giving the h2d its own and having the 2 x ams2’s and ams ht power on another.

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Well the EFD3 has <10ms switch time, so it should be good. I had mixed results with my Delta 2, sometimes it was fast enough, sometimes it wasn’t.

I’m probably going to move it to the garage either way, I go camping too much to take my Delta 3 out of service permanently. Lol.

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It may do if all you want is protection against a neighborhood black out. However, some people here are more concerned about exceeding the ampacity of their house circuit, perhaps because of other loads already on it. In that case, maybe it would switch over in time, but the power failure might be localized to you popping the breaker on your home’s wiring. In theory, the double conversion (as discussed earlier) would allow you to avoid that.

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Nono, I was talking about running the H2D directly off the EFD3, and having the wall replenish the battery at 800w(ish). It’s a 1024wh battery, so it would easily match the minute or two 1.5kw power draw the H2D needs, then recharge back to full while the printer is running, and pulling less power.

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Back with questions. Does anybody know of a ups that lets you set the voltage in which it will swap to battery? And maybe even swap back when the voltage sag stops?

Im thinking if there was one that read the incoming voltage, it could swap to battery when it sensed lower than normal incoming volts. In the case of another printer being preheated on the same circuit.

Also would a line-interactive ups prevent the breaker from popping? There has to be a way of supplying power that the wall cant, without popping the breaker first. If not, someone should invent it and get rich.

I think the ones that let you set the max that they will pull to charge its battery, only act as a passthrough for things plugged into it. And never actually use their battery until the breaker has already popped

As soon as you plug it into the wall, does it not switch to passthrough power and try and charge itself at the same time?

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Almost 2 years ago didn’t BL have the ups for sale on their website?

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Since the high-powered bed heater only works at the beginning of a print, I’d use an affordable 1500 VA UPS with a DPDT switch box to connect the H2D to a wall outlet for the first couple of minutes, and then switch to the UPS afterwards.

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I have the Ecoflow Delta Pro powering my X1C and during failover it can glitch the printer if the load is high. The H2D would possibly be even more likely to glitch but depends on some things.

I had a lot of good failovers until I glitched a print so don’t risk it now. During a mains drop the printer is running off energy stored in the power supply coils and caps. The higher the load, the faster that reserve is used. If power isn’t restored before the power supply uses its reserves, it’s a power cut.

The Delta Pro switches fast but apparently not fast enough in some circumstances (high load).

The solution for me is to just run the printer from the Delta Pro battery (mains off) so it’s already on battery with no switchover. If I need more juice because the battery is down some, turning mains power back on during a print has not had any problem. It’s just when mains drop and that may or may not be successful but usually is.

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Ran this yesterday while printing PC FR with 280* hotend, 110c bed, and 60C chamber. Only using 1 AMS at the time powered through printer.

  • Started Print
  • 1600w for 1.5 min
  • 1100-1200w for 2min
  • 700-800w for 7 min
  • 250ish most of time and would jump to 700-800w every 30sec to a min to maintain temp during print.

hope this helps.

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A victron inverter/charger will not only work as a UPS, but also do power sharing between line and battery. For example, limiting mains power draw to 800W with additional power needs added from the batteries.

While a victron system with batteries is going to be too expensive for 3D printer alone, I’ve considered it as a solution as a more universal home UPS.

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