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Very few USB battery banks can handle charging power being added and/or removed without "restarting". I doubt this works as the author intends: it almost certainly restarts as power comes and/or goes.

Not relevant here, but many multi-port usb-c chargers also stop & start when you plug in or remove another device. Been a long term Ugreen fan, still use the incredibly generic looking 30W charger I bought absurdly cheap from them in 2019, but this behavior is definitely on the Nexode units I have from them (130 & 65W). I did get a OTAO 200w desktop charger & it maintains power as I add or remove devices, which is nice! My monitor runs off usb-c via a 20v DC barrel jack cable, so it's nice being able to plug in a laptop or phone without the screen resetting, ha.

Yep, there's a comment at the bottom in which the author admits that, after further testing, it doesn't actually work.
You're absolutely right about that - power banks that don't have that momentary cutoff are rare and would be highly sought.

However, vermaden is powering a small form factor computer that appears to be able to take anywhere from 12 to 19 volts. This means the power is internally regulated, which means that there's at least some amount of capacitance in the regulation circuit. Many devices like these can handle a drop of power of a small fraction of a second, but likely not more.

For my own SBCs, a rather large capacitor made a power bank I was using work, but the size of the capacitor was unwieldy. I'm more inclined to use an all-in-one charging and battery circuit that feeds the SBC directly.

I'm surprised there isn't already a market for power banks without momentary cutoff. There's quite a market for UPS Pi hats already.

The power bank in question also costs $100 new, which is more than the cost of a UPS and buying a replacement battery
The chargers that drop connection is typically because their max power budget per port depends on how many ports are used. E.g if my max power budget is 200w and I have 2 usb c pd and 2 usb A. Each usb c pd can have a max of 100w per pd3.0 specs. So if I have 2 devices plugged in to both usb c, if I need to plug a USB A device in, I need to lower at least one of the usb C to 65W.
Even if my phone is charging & I plug in a Bluetooth headset, the Ugreen Nexode will drop & reconnect.

I think the OTAO might even allow oversubscribing, where if my monitor or laptop are only using 1/2 what they're negotiated for, it'll let another device join for some addition more. Then only drop a device & reconnect after it actually goes over 200w.

Seems weird but I love the boldness. There's so many USB trigger board systems where the ask isn't right sized, where a device just asks for 3A or 5A but ends up using far less. To me it's a courtesy to look back a bit & decide you can oversubscribe the new guy, and reconnect someone latter... maybe disurptive then. But compared to reconnecting everyone immediately, which is disruptive? Love it.

I have seen chargers that simplify the logic to drop everytime a new device is connected or disconnected to recalculate the max power per port. So these days if I am shopping for a charger say for a IP cam, I assume that each usb C takes 100w and usb A to take 22.5w and calculate what the max draw could be. If the max advertise power budget is at or above this value, then it is a fairly good indication that there will not be any dropping of connection.
That is true and I must sadly admit that I did not tested that ... after some more research I have found that ZMI QB826G 25000mAh powerbank has that 'ups' feature.

I have already ordered one and I will test with that one.

I also need to add some notice to the article that my first approach failed.

Regards, vermaden

I just tried with my pre-ordered indiegogo "No. 20", which is the QB826 (no G).

I haven't tried with a laptop yet, but my phone indeed kept steady power in to it when I connected/removed a charger from the power bank! Neat!! Indeed seems like some level of ups capability!

Confusing naming, but I had & adore ZMI's earlier "20k" power pack. The new No. 20 is 25Ah/2 usb-c/210w, the old 20k Pro is 20Ah/1 usb-c/65w(+ 2 decent usb-a)... But damn the old 20k pro is slick slick slick, great size. I miss it dearly. It's been on some best battery lists & you can still get some on eBay on & off, but it feels like no battery has been as well proportioned since.

It also had something that seems so weird toe that doesn't exist elsewhere: you could put it into a mode where it was also a USB hub with the usb-c device being a host to the two usb-a ports. The usb-a ports only got the 0.9a in that mode, no quick-charge or whatever, but usb-c still got full power & the ports were powered. The idea of a USB charger that also acts as a data hub seems drop dead obvious, and I largely suspect there was some kind of wild IP hijinx/conspiracy that blasted the ZMI 20k out of existence for being so rad.

Thanks for the suggestion! Go ZMI.

This is such a common yet niche ask - silent fanless(light on cpu capacity) but more IO capabilities (NVMe slots, SATA ports, and NICs) for those seeking to make their own NAS. Why aren’t companies like Asus, Gigabyte, etc sell such kits and win the market share? It’s always - here is a ITX motherboard, but it lacks proper storage. Or here is a SOC board with nice storage options but crippled NIC etc. If someone made a product with little to no compromise, and gain the recommendation of the self hosting crowd, more and more newcomers will start buying stuff instead of Raspberry Pis which are way too underpowered for such use cases.
I'm with you, but I don't find the Raspberry Pi underpowered. I'm running 5 Alpine VMs and a Nextcloud snap on top of Debian on a Pi CM4 8GB, with a (now)8 port SATA controller with 6 SSDs and USB3 controller with 2 hard drives attached through a PCIe switch, and it's absolutely fine and pulls around 13-17W idle-ish and spun down. It doesn't max out gigE on long writes, but it matches my friend's 8 bay Synology at around 900Mbps. Perhaps I'd need more CPU if I were transcoding, but I have no requirement for that. I suspect a Pi CM5, with its more and faster PCIe lanes, will kick off some really interesting opportunities in this space.
It's wild that a Pi now uses more power than a box with a U/T sku Intel CPU!

Combined with the high prices it has pushed me completely away from the Pi.

The PCIe switch, SATA controller and USB3 controller all add a fair bit of power compared to having those functions integrated into an SoC built on a better process. But that also means it's not entirely fair to say the Pi is using more power; it's the system as a whole using more power because of all the extra parts needed to overcome the Pi's limitations.
Sure, but an x86 box has all of those built in already.
Yes, that was my point. An x86 box has lots of built-in (and power-efficient) IO capabilities that are not part of the Raspberry Pi. When adding a bunch of IO-expanding peripherals to a Pi-based system, you should properly attribute the power consumption instead of making it sound like the Pi itself has a serious idle power problem.
That power footprint also includes the 6 SSDs. Are there mini PCs with 8 SATA ports that fit in a 13-17W power envelope including 6 disks?
SSDs idle at like 0.2W IIRC, so 6 of those shouldn't have much impact on overall power.

Not sure on 8 SATA ports as most only have 3-4, but I'd be using NVMe SSDs if I could these days anyways, main boot drive in the motherboard and some more on a PCIe addon adapter.

8TB NVMe SSDs are rather expensive, and I'm running 3x 8TB SSDs in addition to 2x 2TB and a 512GB boot volume. Cost was not a major constraint on this build, but paying 1199.- vs 399.- for an 8TB SSD felt a bit comical.

I also can't make any use of NVMe performance benefits when a SATA SSD can more than fill a 1Gb Ethernet pipe, or even a 2.5Gb or 5Gb pipe. Only a 10GbE system would benefit from being able to push more than 550MB/sec, and even that could be met by multiple SATA SSDs in parallel.

Here's an option for small form factor builds. https://github.com/mini-box/openups2
This product is great - it seems to be intended for internal installation into desktop towers, but it is infinitely configurable and can operate as a portable power pack with user-selectable (via dip switch) output voltage. 3-D printed enclosures are online at the usual places. I use it as a UPS for my router.
That power bank serves a niche for me I've been searching a while for. I have a sound (white noise) machine I use for sleep, but it's pretty susceptible to brown outs or dirty power and that's pretty jarring. It's powered by USB, and I've never been able to find a UPS that meets:

- Small

- Cheap (I wouldn't consider $99 cheap, but it's better)

- Seamless switch between power and battery

I've thrown a small battery pack on before but the battery wouldn't charge and serve at the same time.

One of the commenters on the post was struggling with the same thing, and found a battery bank that advertises seamless switchover between charging and power -- the ZMI QB826/QB826G 25000mAh. Amazon it's around $160, Aliexpress is around $100.
This is neat, but using an off the shelf power bank and keeping it plugged in is going to destroy the battery in a year or two. Those Li-ion pouch cells deteriorate rapidly at 100% charge, especially in a warm environment.

It's better to use a DIY DC UPS with some LiFePo4 cells, that only charges them to 80% or so. And you won't have any issues with power reset.

There's also much more of a fire risk when using Li-ion cells compared to LiFePo4.

At one point I was using an old phone as an IP camera and I had it plugged in to a battery bank that was constantly charging. The battery bank died pretty quickly, I think within weeks. Then I just plugged the phone directly into power, and the phone battery died eventually too (it started bulging, glad I noticed before it got worse). So yeah, Li-ion batteries don't like constant 100% power.
Or you can use Lead Acid, which actually likes being at 100% perpetually.

12V 7AmpHr lead acid is a big standard battery that should be good enough for most people. A Dc DC Buck converter to 5V is like 16+ AmpHr at 5V.

Came here to mention this. I used this exact setup (used a laptop battery bank off of amazon as a UPS for my home modem), and came home months later to find the bank had caught fire at some point, melted, and was no longer functional. Would not recommend
The title brought to mind the Helios64 NAS, an unfortunately dead project from a few years ago I followed for a while in the hope it would become widely available. It had a small UPS inside; putting Lithium cells near hard drives is not the best idea in my opinion, but the platform was quite neat nonetheless.

https://wiki.kobol.io/helios64/intro/

Plus it has ECC RAM support!
Hi, I have the ZMI QB826G and I'm 99% sure it blips the power when starting passthrough. Do really like the thing though (except for the display that remains on while in use and is fairly bright)

I have another solution for you: I've been using https://de.aliexpress.com/item/1005005036674891.html for my router and it's been pretty good so far for the six months or so I've had it. I was made aware of it from an electronics Youtuber I trust who did a teardown and was impressed with the quality and safety. Sorry I can't find the video at the moment.

I enjoy the PoE vs PoE+ selector being labeled simply “Lorem ipsum”
I was made aware of it from an electronics Youtuber I trust who did a teardown and was impressed with the quality and safety. Sorry I can't find the video at the moment.

If you ever manage to find the teardown video again, a link would be much appreciated!

Won't an UPS also switch to the battery during brownouts/other power quality problems? Which is good for your circuits.

Also, depending on how well these power banks are made, it may be a fire hazard...

As I investigated this field, the more I realize that the cellular phone has a lot of similarities to the always on NAS+SERVER+UPS combo. Makes me wonder if Apple will ever enter this space. They used to have pretty polished interfaces for their AirPort Extreme brand, and they were selling Xserve products in the past. Personally I think the home router space will grow for self hosted AI, storage, etc. which is somewhat at odds with Apples focus on subscription service and iCloud.