[HN Gopher] Potential Issues of Using a USB Powerbank as a UPS (...
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Potential Issues of Using a USB Powerbank as a UPS (2021)
Author : walterbell
Score : 187 points
Date : 2022-10-04 07:15 UTC (15 hours ago)
(HTM) web link (goughlui.com)
(TXT) w3m dump (goughlui.com)
| exikyut wrote:
| Tangentially related question I'm actually trying to answer in
| earnest at the moment:
|
| I want to put together an EDC portable Linux box using something
| like a Radxa Zero or OrangePi Zero, with the idea that it'll run
| for some nominal amount of time away from a wall outlet.
|
| A power bank is obviously the answer, but I don't want "push the
| status button and guess at what the 5 LEDs are saying" to be my
| answer to "how much power is available?". I want something I can
| ideally turn into an ETA, so that I can then monitor that ETA and
| send myself alerts when the battery is critically low.
|
| I've found RPi hat "UPSes" that seem to provide exactly this data
| over I2C... but none of these seem to also provide an all-
| important enclosure that would ensure I don't accidentally short
| anything out and literally burn a hole in my pocket. Not viable.
|
| I've not yet explored the world of 3D printing, but I do
| understand enough to be know that my first 3 or 5 or 28 prints
| will be slightly janky. :)
|
| So, I'm trying to find a premade solution to this problem -
| either a power bank that provides Actual Data(tm) over the USB
| connection (!), or some kind of devkit-style solution that'll
| viably/safely fit into a standard enclosure of some kind.
| dicknuckle wrote:
| Find someone locally who has a 3d printer. If you don't already
| know how to model 3d objects, they will likely charge you for
| that time and then 3d print a test. Then when you have it
| right, there are plenty of pro shops that can produce a more
| permanent 3d object through Laserjet Fusion or other methods.
| rektide wrote:
| One of those plagues of shitty consumerism & no market
| pressure: there's a standard that works great but no one
| implements it, cause they suck & are no good & there's no
| consumer pressure to do basic shit.
|
| USB HID has all kinds of sensors & telemetry it can do. USB HID
| includes a whole sub-spec on Power Devices, with all kinds of
| information that chargers & batteries can report. To take one
| example, the Battery System Page (x85) can report Current,
| Voltage, Temperature, Absolute/RelativeStateOfCharge,
| RemainingCapacity/FullCapacity, RunTimeToEmpty,
| ChargerConnection, OutputConnection, ChargingIndicator, and
| CycleCount (among many other factors) to tell you what is
| happening. You can set RemainingCapacityLimit or
| RemainingTimeLimit to trigger a USB alarm condition when
| capacity falls under threshold. You can monitor individual
| inputs & outputs separately.
|
| (The one ask I have that's not supported by the spec: a
| StopChargeAtCapacity setting for batteries, so I can stop my
| UPS's 5000mah battery at 4200mah to extend it's life
| drastically)
|
| It's a stupid senseless world where the obvious never happens.
| Consumers aren't educated enough to have sensible asks. What is
| possible is ignored. I'll try to break out 'lsusb' more in the
| future when charging, but my impression is that basically no
| one- not batteries nor chargers- implements the ancient,
| obvious, sensible, & easy spec for power devices to report the
| basics about what they are doing. For shame!
| joshspankit wrote:
| > StopChargeAtCapacity
|
| I'd also love to see this on power bricks so that I can tell
| the charger to stop charging my phone and tablet at 80%,
| regardless of what the device manufacturer gives in terms of
| software control
| nine_k wrote:
| Something like OpenUPS2 [1] seems to provide data over USB, and
| even has Linux software to support that. It does not seem to
| have an enclosure though; it's apparently intended to be put
| into an enclosure of the device it supports. Also, pricey.
|
| [1]: https://www.mini-box.com/OpenUPS2
| mmastrac wrote:
| About 10 years ago I tried using an Anker power bank for a UPS.
| It had some issues w/shutting itself down when switching power
| modes. I reached out to their support line and they completely
| misunderstood my questions, sending me a brand new battery
| instead despite my protest. I was hoping to just send some
| feedback on what I thought were firmware issues.
|
| In the end I got two beefy Anker power banks that didn't work as
| a UPS, and eventually migrated myself over to using PoE power for
| the Pis (AliExpress gigabit -> 5V/3A PoE extractor), with a Unifi
| Dream Machine Pro SE powering them.
|
| My UPS is now a used, enterprise Dell 1300W monster that pretty
| much runs the entire local networking stack + servers for nearly
| an hour without power.
| INTPenis wrote:
| The title makes me remember my raspberry pi camera I made for my
| apartment in 2011. I hooked it up to a simple USB powerbank at
| the time, and then the powerbank to the power outlet. Thinking if
| anyone cut the power to my apartment it would still record for 15
| minutes.
|
| Of course had anyone cut the power to my apartment it would have
| no way to upload the recordings because I didn't add a 3G
| failover.
| xani_ wrote:
| I remember some article of someone trying it, only to discover
| their power bank cut power for few milliseconds when you
| disconnected the external power supply, resetting the device...
| sys42590 wrote:
| I really love the fact that the presented circuitry avoids fully
| charging the battery cells to extend their lifespan.
|
| SO many consumer electronics intentionally charge lithium cells
| to their limits to boast long battery run times and high
| capacities in the specs while severely shortening the products
| lifespan.
| UniverseHacker wrote:
| Lithium batteries are awesome, but I think lead acid just makes
| a lot more sense for a UPS- they like to be fully charged, last
| virtually forever when maintained that way, and don't require
| any complex charge management circuitry.
| Merad wrote:
| > they like to be fully charged, last virtually forever when
| maintained that way
|
| If that's the case why do the lead acid batteries in consumer
| UPS's never last more than 3-5 years?
| UniverseHacker wrote:
| I think cheap batteries, poorly designed starter circuits,
| and occasional full discharge in use, which all coordinate
| to damage the batteries early. Also if your power is low
| quality, it causes the device to switch to battery often,
| and can put a lot of cycles without actually having a power
| outage. High quality lead acid batteries in solar systems,
| car starting, and commercial UPSs often last a decade or
| longer.
| 1-6 wrote:
| VRLA batteries are commonplace for commercial UPS units.
| For lithium, I'd explore LiFePO4 batteries. Not all
| lithium chemistries are alike and LiFePO4 are considered
| safe. It doesn't have great capacity to weight ratio but
| it wasn't meant for consumer electronics anyway.
| cat_plus_plus wrote:
| If you have corruption or super long reboots on brief power loss,
| you have a bigger and unnecessary problem, because UPS can also
| fail and for many applications a brief service loss is otherwise
| acceptable. For example, I often handle California power outages
| by running an inverter off my car and powering up my home network
| through a cord run through kitchen window. If my NAS got borked
| in between, that would be very unfortunate. Your point stands in
| regards to equipment like security cameras where continuous
| availability is the point. But would a Raspberry Pi usually be
| the best choice vs special design equipment with built in backup
| batteries and low idle drain or say a cheap Android phone running
| an appropriate app?
| heythere22 wrote:
| Dave from EEVBlog had the same issue. His mains power battery
| does not do 0ms switching:
| https://www.youtube.com/watch?v=5JT8M8v_zNg
|
| Semms like, if you want the features of an UPS, you should get a
| UPS.
| yencabulator wrote:
| > Herein lies the problem - just because you have pass-through
| charging does not mean that your output is uninterrupted.
|
| Okay, so this Framework laptop I'm typing on can power from any
| of its 4 USB-C ports. Ignoring that it already has a battery (you
| can buy just the motherboard and a non-laptop case), doesn't that
| work around this neatly?
|
| Plug one USB-C directly to wall, plug second USB-C to powerbank.
|
| For absurdity, repeat until you have a highly available array of
| 3 powerbanks. You can even put them on timers so you don't need
| pass-through charging!
| aristus wrote:
| Living in Mexico City around a lot of construction, I've had my
| heart (and kit) broken by dirty, inconstant power. For small
| things like a Wifi repeater a 10Ah battery inline works ok. But
| for anything beefier or without its own internal battery, eg a
| NAS / printer / modem, you still need a proper UPS.
|
| The end result is we have a 750-100VA box under every desk and
| one in the comms closet. Unsurprisingly even small office supply
| stores around here have a wide selection of UPS and power kit.
| axiolite wrote:
| Get a 12V SLA battery, solar charge controller, 14-20V AC
| adapter, and a USB car charger if you need 5V output in addition
| to 12V. DONE!
|
| The "DC UPS" units you can find for sale (as well as USB power
| banks) don't have any monitoring/data connection. Real UPSes have
| them to tell your systems to perform a clean shutdown when the
| battery gets low. Since they're all just simple dumb batteries
| anyhow, you might as well roll your own for less cost and much
| more runtime...
|
| To make it a proper smart UPS, you would just need to add a low-
| voltage trigger that talks over USB, RS-232 or Ethernet.
| Something like a 12V relay could act as a "contact closure"
| signal, though you'd have to test the cut-off voltage and perhaps
| try a few different values of resistors to fine-tune the low-
| battery signal.
| rwmj wrote:
| I got a large power bank (Bluetti EB55) to get me through the
| expected power cuts this winter. Supports charging from mains
| or solar while supplying power. Of course at PS900 it's hardly
| a cheap option ...
| greggsy wrote:
| Why over complicate it with electronics? It's a computer.
|
| Just have your device shutdown when it can no longer poll
| another device. For example, if the router or some other
| network device isn't contactable for longer than two minutes,
| it might indicate that the power is out.
| goodpoint wrote:
| And you call that "simple"?
| asdff wrote:
| You could do it with a bash one liner
| justsomehnguy wrote:
| And couple of months later you are investigating why the
| branch gone dark in the middle of the day.
|
| No.
|
| Devices should survive powerloss, devices can have a graceful
| shutdown from an external source.
|
| Key is in your "might".
| unregistereddev wrote:
| The router is one of the first things I put on a UPS. The
| telco equipment likely has fallback power as well.
|
| Sure, you could find some device that isn't on a battery
| backup and ping it regularly. But this approach forces the
| device on your UPS to shutdown as soon as power is lost. That
| buys you a clean shutdown, but you don't get the added
| benefit of being able to run without interruption during a
| brief brownout.
| [deleted]
| tenebrisalietum wrote:
| I heard of connecting an old modem to a serial port for this
| purpose. If it doesn't respond to any AT commands then power
| may be out.
| Nextgrid wrote:
| Any networked device will do - switch, router, etc. If
| there's no link on the port, power is down. USB-C Ethernet
| adapters with power pass-through will generally power the
| Ethernet module off the USB-C power port even if no host
| device is plugged in. USB-to-Ethernet adapters _may_ also
| light up the port even if only connected to power (and not
| a host device).
| jacknews wrote:
| Sure but you'd need bigger pockets, probably even a bigger
| backpack.
| dicknuckle wrote:
| Also a much bigger timeframe for testing and development.
| This isn't something you slap together in a weekend and call
| good. More like building an experimental drone than putting
| together a 3d printer kit or building a PC
| crashingintoyou wrote:
| Sure the "DC UPS" are basically "simple dumb batteries", but
| the sort of loads that you'd probably run off them and the
| expected runtime of each tends to be quite different.
|
| Guessing the average AC UPS that someone might back a desktop
| with might last 5 minutes (or in a data centre long enough for
| the generators to kick in). A "DC UPS" running a router or a
| raspberry pi likely has a runtime measured in hours. Still
| would be nice to have monitoring info available, but more time
| for human intervention to shut down if need be.
|
| "you might as well roll your own for less cost and much more
| runtime..."
|
| Depends on how much gear you want to power. If you just want to
| keep a raspberry pi online a few hours I doubt you'd save much
| money (if any) rolling your own. Could be fun as a project
| though.
| Melatonic wrote:
| I have made a standard USB-PD powerbank into an ACTUAL UPS by
| connecting a small board that allows you to manually select the
| voltage of the output. By selecting 12V you can then wire up any
| 12V device of reasonable power (say a wireless router) to the USB
| powerbank. There is no loss converting to and from AC and the
| power bank internals still handle all the complicated charging
| and whatnot. All the little IO board does is request a specific
| voltage (in the same way that any device with PD will negotiate)
| and keep it there.
|
| I also found a small fanless inverter that I wired to this setup
| which gave me a tiny and completely silent AC power device. Super
| small, super portable. Easily powers a few LED bulbs or strings.
| metadat wrote:
| Is there a proper name for the "small board" you mention?
| simplyaccont wrote:
| there are keywords like "usb pd decoy"
|
| https://smile.amazon.com/gp/product/B07T6LPP9W
| planede wrote:
| What's the typical circuit found in a laptop or phone? They all
| have to deal with this stuff internally.
|
| IMO a cheapo x64 laptop is better than a raspberry PI + some
| jerry-rigged UPS setup for a low-power home server setup, YMMV.
| selfhoster11 wrote:
| That depends on the amount of stuff you're running, and how
| much you care about the UPS working. If the answer to both is
| "very little" or "not much", I'd take the Pi setup any day.
| mbreese wrote:
| It also depends on how often you expect to lose power. If
| that answer is "somewhat often" or worse, then even a minor
| annoyance can be worth avoiding. There's a reason laptops
| used as a server were known as "California servers". (aka a
| server with a built in UPS)
| mschuster91 wrote:
| > What's the typical circuit found in a laptop or phone? They
| all have to deal with this stuff internally.
|
| Most phones and laptops operate at the "micro-cycling" mode
| that the author describes, it's part of why portable devices
| regularly end up in the news for swelling batteries. There's no
| brand that didn't have complaints by people.
|
| Additionally, the power quality of shoddy chargers [1] makes
| life even worse for circuit designers - voltage ripple or,
| worse, spikes that rise fast enough to hit the battery... the
| list of problems is quite endless.
|
| [1] https://www.righto.com/2012/10/a-dozen-usb-chargers-in-
| lab-a...
| deckard1 wrote:
| I always see recommendations on /r/HomeServer for using a
| laptop and I always shudder a bit. I had a battery swell on a
| Macbook. The thought of leaving a laptop running unattended
| for months at a time, possibly stuffed in a garage or closet
| where you won't be watching it for awhile just sounds like a
| disaster waiting to happen.
|
| The other thing is that if you have a laptop worth using as a
| server then you have a laptop _probably_ worth selling. Use
| that money to buy a proper UPS and cheap server and you may
| even have money left over. You also can 't plug routers or
| cable modems into a laptop, so it's rather pointless anyway.
|
| I have a UPS because I'm hit with short brownouts every
| summer (yay, California). But if my grid was better and I
| only saw outages every few years then screw it. Let the
| server crash. This isn't the 1980s. Nearly all filesystems
| and databases (ACID, anyway) recover just fine today. Use ZFS
| if you're truly paranoid.
| eternityforest wrote:
| Hard to believe USB-PD upses aren't a common products.
|
| There's no reason anymore that a power bank should ever even have
| an off mode unless it's so cheap there's no passthrough, which
| shouldn't be a thing either because it's annoying and probably
| saves 50 cents.
|
| It's microamps with a good eco mode switcher.
|
| Inline USB ultracapacitor banks seem like a reasonable product
| too though.
|
| Hopefully USB will give us standards for power banks someday so
| you can get certified ones with a defined form factor and
| behavior.
| Dalewyn wrote:
| >USB will give us standards for power banks
|
| USB Energy Provisioning Aggregate Network 4.3 Revision 11
| Gen3x4 48gbps SuperCharge-C.
| dividedbyzero wrote:
| Sorry, can't do better than 5W with that pricey Revision 12
| Gen4x4 cable of yours.
| Dalewyn wrote:
| Electricity is measured in gbps as ordained[1] by the USB-
| IF. We must be universal.
|
| [1]: https://cdn.arstechnica.net/wp-
| content/uploads/2022/09/USB-p...
| dividedbyzero wrote:
| Yes, but between Revision 11 and 12, all manufacturers on
| the consortium unanimously voted to up all voltages by
| 0.4V to increase incompatibility. Still the same gbps
| though.
| RHSeeger wrote:
| There's something sort of horrifying in the fact that I
| can't tell if the posts in this thread are real ... or
| fake in pretending to be a bureaucratic, ridiculous joke.
| therein wrote:
| Traumatizing.
| justinjlynn wrote:
| Nah, it'll be USB-P PB (LiIon Annex 3) UP 2+++ over USB-C
| (constant cycle) USB-P 2+++-compatible (certified)
| connectors.
| hoseja wrote:
| For some reason I still cannot fathom, the 50-cent saving is a
| point of great pride to electrical engineers. They repeat some
| phrases about million-unit manufacturing runs and I just seethe
| with anger that we can't have nice things.
| goodpoint wrote:
| No, they are required to do that by management.
| babypuncher wrote:
| I imagine it's a similar feeling of pride felt by the
| engineers who design outdoors equipment that only fits in the
| provided container when folded precisely how it was at the
| factory with no margin for error.
| llampx wrote:
| Its more the operations/supply chain/bean counting
| department.
|
| It goes like "They'll never know the difference!" and pretty
| soon you've gone from a premier brand to a cheapo outsourced-
| to-China generic product.
| kube-system wrote:
| You can have nicer things, you just have to pay for it.
|
| But because of economies of scale, you don't just pay the
| difference in BOM cost, you pay that difference _plus_ the
| difference in fixed costs divided by a much smaller unit run.
|
| USB UPSes exist, and they're really not that niche. Amazon
| has one for $50. That's mass-market pricing as far as
| electronics are concerned.
| m463 wrote:
| As far as I can tell, there are a few no-name DC-only ups
| systems, but it would be really nice to have a USB-only DC-
| only ups that did things like USB-C with PD.
| GekkePrutser wrote:
| APC has a DC UPS but iirc it's 12V only. Mainly intended
| for routers etc.
| walterbell wrote:
| Good case study for Harvard Business School. When a design
| engineer wants to cut a feature to save a few pennies, they
| are teamed with a marketing pair-analyst to assess the TAM
| and margins, considered holistically with other feature
| subsets.
| spookthesunset wrote:
| > 50-cent saving is a point of great pride to electrical
| engineers
|
| As an engineer you are given a power budget, a thermal
| budget, a size budget, a weight budget and a monetary budget,
| among many other constraints. This means, like any
| engineering endeavor, there are tradeoffs to make. That
| 50-cents you saved on some power controller might be "spent"
| somewhere else that has a higher impact on the product.
|
| There is a near infinite set of things you can do to make the
| product better somehow. Unfortunately you don't get to do
| them all. Many of the things conflict with eachother--more
| battery life might mean more weight and size that you have to
| "steal" from some other aspect of the product to balance out.
| Faster, better charging might cost 50-cents but that might
| mean in order to stay on budget you'd have to use a lower
| quality plastic shell that is more prone to damage. That
| faster, better charging might also eat into your thermal
| budget, meaning you'll need to spend more on cooling, weight
| and size.
|
| It's all tradeoffs. There is no free lunch.
| xani_ wrote:
| It's not EEs, it's beancounters, EE's are just paid to please
| them. Just like developers really
| sorenjan wrote:
| Anker has a power bank with integrated charger[0], or charger
| with built in power bank. Don't think it's made to be used as a
| UPS, but maybe it can be.
|
| > Inline USB ultracapacitor banks seem like a reasonable
| product too though.
|
| I actually saw just that in a GreatScott Youtube video about
| Aliexpress gadgets just the other day[1]. Not sold as a UPS,
| but rather a power filter or buffer.
|
| [0] https://www.amazon.com/dp/B085CFD3Z9/
|
| [1] https://youtu.be/fUdlfc1nJcY?t=117
| reaperducer wrote:
| The ChugPlug saved my bacon more than once when stuck in the
| desert at night a hundred miles from power around 2005:
| https://www.ilounge.com/index.php/mac/entry/lenmar-chugplug
|
| Weighed more than my MacBook, but indispensable. Too bad they
| don't make them anymore.
| wlesieutre wrote:
| Laptops can run off of any USB-C power bank now, so it's no
| surprise there's no market for something like this. Cool
| product though!
|
| It's on the line voltage side like any other UPS, so not as
| efficient as you could be with a solution that didn't have
| to convert AC to DC then back to AC then to DC again in the
| brick. But with Apple's proprietary charging connector
| soldered to the device end of the brick, what else can you
| do about it?
| Scoundreller wrote:
| My MacBook Air will happily draw 5w at 5V from a USB-A
| power bank from years ago through the laptop's USB-C
| connector.
|
| In short, it will take whatever it can get and boost.
|
| Kinda inefficient to run 2x boosts, but it does the job.
|
| Will buy you time during use and slowly charge while
| closed.
| xani_ wrote:
| > Hard to believe USB-PD upses aren't a common products.
|
| Insanely easy to believe. The role of UPS is to prevent data
| loss when power fails. If something is powered by USB-C it
| almost always already have its own battery preventing from
| that.
|
| The only devices that are not are stuff like say, raspberry Pi
|
| Also, there literally are devices like that, just aimed more at
| stuff like camping, so much bigger battery, usually an inverter
| on board and solar input.
|
| > Hopefully USB will give us standards for power banks someday
| so you can get certified ones with a defined form factor and
| behavior.
|
| If it will be like USB-PD then it will be insanely
| overcomplicated and nobody will be able to get it right.
| flutas wrote:
| > The role of UPS is to prevent data loss when power fails.
| If something is powered by USB-C it almost always already
| have its own battery preventing from that.
|
| That's a very narrow minded approach to both UPSs and items
| using USB as their power plug imo.
|
| A UPS isn't just "to prevent data loss when power fails."
| It's also to keep critical (for home, not DC) things running
| in the event of power outages. Current uses for USB-C power
| banks as UPSs I have (or have recommended to friends) that
| aren't "to prevent data loss".
|
| - Power bank running as a UPS on (a few critical) wireless
| security cameras (that use USB-C for power).
|
| - Power bank running as a UPS on my cats water fountain (uses
| USB for power), if the power goes out she still needs to
| drink water, and I may not be home to put down a standard
| bowl.
|
| - Friend has a baby monitor and took my idea of using a USB
| power bank as a battery backup on the camera and monitor so
| that if his power goes out he can still keep tabs on his
| child. (no sense waking her up to move her if he doesn't have
| to)
| dotancohen wrote:
| There may be a market for an ATX USB-PD power supply. My
| desktop has no spinning rust nor discrete video card. A 60
| watt power supply could power it easily, especially if there
| were a small lipo for the occasional burst.
| moolcool wrote:
| > Insanely easy to believe. The role of UPS is to prevent
| data loss when power fails. If something is powered by USB-C
| it almost always already have its own battery preventing from
| that.
|
| That's a moot point though, IMO. Like if you're travelling,
| wouldn't it be nice if your charger and your battery bank
| were the same device? Just because it doesn't have the same
| specific utility as a UPS, doesn't mean that it's not useful
| in other ways.
| kube-system wrote:
| > wouldn't it be nice if your charger and your battery bank
| were the same device?
|
| Like this?
|
| https://www.anker.com/products/a1621
|
| There's a lot of these devices. "Wall plug power bank"
| worked as good keywords for me on Amazon.
|
| These could still be different in operation than a UPS
| though
| dude3 wrote:
| I tried this it does provide power like a ups but it cuts
| out for a moment and restarts the device.
| GekkePrutser wrote:
| > The only devices that are not are stuff like say, raspberry
| Pi
|
| Or IP cams, I have some here that sounds really benefit but
| I'm worried about the safety of a powerbank plugged in 24/7
| that's not meant for it.
|
| I could see it being a thing. A niche thing but a thing.
| jacknews wrote:
| Exactly, even 5000mah in your standard USB-PD 60w adapter would
| be a huge boon, especially for laptops where the internal
| battery has begun to fail and replacing the battery means
| replacing half the laptop, app..cough..le
| nicolaslem wrote:
| > replacing the battery means replacing half the laptop,
| app..cough..le
|
| These kind of comments are surprisingly common on HN and
| annoy me slightly.
|
| Yes, most phones and laptops do not have user replaceable
| batteries anymore. It's a pity. That does not mean a dead
| battery is a justification to throw away fine equipment.
|
| Any phone repair shop or computer shop can replace batteries.
| They usually have all the equipment and spare parts, even
| more so for popular Apple devices. It usually takes half an
| hour and costs way less than replacing the whole device.
|
| I always recommend that to friends and family because most of
| them are not even aware this is possible. They usually thank
| me later saying how painless and affordable it was to give a
| second life to their devices.
| snerbles wrote:
| > where the internal battery has begun to fail
|
| Assuming the default failure mode of the battery is degraded
| capacity. Over the years I've had an alarming number of
| lithium-polymer batteries puff out in consumer devices
| ranging from my Dell XPS 13 (9343 model, battery was replaced
| three times) to the Moto Z Play phone (dislocated the screen,
| replaced twice by Asurion, third time they claimed it was a
| warranty issue and played support tennis with Verizon) to an
| iPod Touch (also popped the screen out).
| dylan604 wrote:
| I just did a battery replacement on a 2017 MBP. While there
| were a lot of screws needing to be removed and lots of
| lifting/prying to get to cables, half the laptop did not need
| to be replaced.
|
| Now, if you said the keyboard...
| GekkePrutser wrote:
| The keyboard and the whole topcase if you do it the
| official Apple way.
|
| I can see how someone would call that half the laptop.
| Dalewyn wrote:
| >replacing the battery means replacing half the laptop
|
| And that's assuming you can even find a decent replacement
| battery.
| dtx1 wrote:
| If you are going to use lithium batteries for UPS purposes, you
| should look into lifepo batteries. Much safer for that purpose
| gambiting wrote:
| What makes them safer? Can you explain please?
| dtx1 wrote:
| They are in no particular order more resistant to under and
| overvolting, much more cycle resistant, much more resistant
| to storage under high charge level, much harder to get to
| explode etc. For UPS purposes they are the correct choice all
| around-
| AzN1337c0d3r wrote:
| Basically, they are much less likely to vent violently.
|
| https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery.
| ..
| neilv wrote:
| For some non-UPS but related use cases... I don't think it's
| uninterrupted, but I use this Anker PowerCore Fusion III as my
| main wallwart USB-C fast-charger, with the bonus that it also
| keeps its own internal 5 Ah battery charged:
| https://www.amazon.com/gp/product/B085CFD3Z9/ Current model might
| be: https://www.amazon.com/dp/B01K702S66/
| riobard wrote:
| > To treat the cells well requires sacrificing some capacity to
| reduce the voltage stress on the cells.
|
| Battery-power devices like smartphones should have a mandatory
| control of what percentage of battery it should be charged up to.
|
| For Mac there's this nice utility AlDente
| https://apphousekitchen.com
| pitaj wrote:
| I think this is a standard feature on Samsung phones, but I
| really wish it was standard in Android.
| yjftsjthsd-h wrote:
| https://github.com/sriharshaarangi/BatteryChargeLimit seems
| to work anywhere there's root access (though yes I absolutely
| agree that it should be a standard part of the OS)
| permo-w wrote:
| >Herein lies the problem - just because you have _pass-through_
| charging does not mean that your output is _uninterrupted_
|
| the author says this as if the two are easily confused, when its
| him that makes the association in the first place. why would you
| assume this at all?
| dividedbyzero wrote:
| Knowing very very little about battery technology I wouldn't
| expect an interruption when starting to charge a pass-through
| power bank either. I'd expect charge controllers to handle this
| seamlessly, like the ones I get on those microcontrollers that
| support batteries out of the box (which are dirt cheap too), or
| the one in my laptop, or the one in pretty much all other
| battery-powered devices; those don't switch off when
| connecting/disconnecting to/from mains power. If that's so
| well-understood, why would a decent power bank not do this as
| well?
|
| Actually, my big Anker 521 (256Wh) does provide pretty much
| uninterrupted power when connecting/disconnecting to/from
| mains, though it did switch off randomly once after a few days.
| walterbell wrote:
| ZMI no20 claims to support uninterrupted UPS mode, but doesn't
| seem to be available for purchase,
| https://www.macworld.com/article/539605/zmi-powerpack-no-20-...
| Snuupy wrote:
| ZMI Ambi (10k mAh/18W) does as well. Likely discontinued and
| replaced by a newer model now though. Perfect for a rpi UPS.
| rektide wrote:
| My ZMI PowerPack 20k & 20k Pro's are still my daily drivers
| (good for 45W/65W only, but fine for my use), but I did snag
| one of these off the indiegogo (for the high-speed dual port
| capability). I hadn't realized it has this uninterrupted
| capability- awesome. I use USB-C to dc-barrel jack adapters,
| and this it an makes an affordable, reasonable capacity UPS.
|
| It seems to still be available on alibaba and ebay.
| https://www.aliexpress.com/i/3256802290206038.html?gatewayAd...
|
| It is truly excellent seeing battery packs with >1 input-output
| USB-C port (100W and 45W combined).
| roboben wrote:
| Market gap! Someone should produce USB UPS for the raspberryPi
| server setups of this world. I'd buy one!
| ramraj07 wrote:
| Not usb but mini UPS to keep your modem going is a common thing
| in India nowadays given constant power interruptions.
|
| Ironically I got mine before I learned of the power cuts in my
| new home while building it. I was just merely thinking of edge
| cases of how a smart thief could undo my security cameras and
| figured cutting off the power would be one option I need to
| prepare, so got this UPS to backup both the modems (and
| redundant internet connections) and the home bridge for the
| battery backup security cam.
| crashingintoyou wrote:
| Not really a market gap.
|
| Hit Amazon.com and search for "raspberry pi UPS" and you'll
| find plenty of options. Or more generically try search terms
| like "mini ups" or "router ups" or "dc ups" - loads of options
| at places like Aliexpress as well.
|
| Here in South Africa with rolling blackouts happening fairly
| regularly these days a lot of homes have something similar to
| keep internet connectivity live when it happens, with a lot of
| those options having USB outputs as well.
|
| I'm currently using one of these to keep my pi 4 + hdd setup
| online: https://acconet.net/product/ups-rp7500a/
| roboben wrote:
| This thing looks great, also given the PoE feature. How much
| does it cost? I cannot seem to find it to buy
| walterbell wrote:
| Similar-ish PoE UPS for $55 USD,
| https://www.amazon.com/Battery-Uninterruptible-
| Security-1000...
| exikyut wrote:
| A cursory search of AliExpress found these potentially
| interesting candidates:
|
| https://aliexpress.com/item/1005003164049579.html,
| https://aliexpress.com/item/1005004107179526.html (POE)
|
| https://aliexpress.com/item/32964061367.html (wall wart
| style)
|
| https://aliexpress.com/item/1005003765804094.html (looks
| like a power bank with always-on output like the article is
| describing)
|
| https://aliexpress.com/item/4001204992959.html (BYO 18650s
| and enclosure)
|
| https://aliexpress.com/item/32421259702.html (looks
| interesting but sadly "dead", was cached in google search
| results from however long ago)
| dividedbyzero wrote:
| Not quite that but I ordered an Eaton 3S 850, which is a beefy
| power strip with built-in battery and looks like a decent
| compromise for cases where you don't really need a huge noisy
| rack-mounted UPS, but something that can do a bit more than
| just a Raspberry Pi (i.e. several Pis plus the router).
| roboben wrote:
| That's my point. Why having all the setup (and size!) for
| doing 110/220V when you just need it for 5V USB.
|
| Still a nice option!
| dividedbyzero wrote:
| But would you only need 5V? DSLAMs here have an hour or so
| of UPS capacity as well, so if the router stays up, so does
| the internet connection, same with 4G/5G routers. Though I
| guess a 5/12/24V DC mini-UPS would still be a lot easier
| than actual 110/220V AC.
| swores wrote:
| Already exists, e.g. using the PiJuice HAT as explained here:
| https://howchoo.com/pi/raspberry-pi-ups-uninterruptible-powe...
|
| (Disclaimer: no experience myself, just remembered seeing
| multiple HATs in this area in the past so did a quick search)
| Ductapemaster wrote:
| I used one of these for about a year on my PiHole, but
| switched to a standard UPS because the hat's LiPo started
| bulging from all the heat generated by the Pi's processor.
|
| The hat is a great idea in principle, but because the battery
| is sitting right on top of the processor, it doesn't stand a
| chance given that lithium batteries are fairly temperature
| sensitive.
|
| I'd go with another option.
| swores wrote:
| Good to know, thanks!
| roboben wrote:
| A HAT seems to by way to complex and less flexible then a
| small black box you can plug your USB charger in and a USB
| cabel comes out
| dicknuckle wrote:
| Then you have a string of devices that need to be connected
| together in a more n rigid fashion, either in separate
| compartments of a bag or case with a USB cable between, or
| strapped together with tape.
| rwmj wrote:
| Really? I'd far rather have a UPS hat than another external
| brick, assuming the hat provided passthru so it didn't
| block the addition of further hats.
| swores wrote:
| And indeed that one does:
|
| " _PiJuice will use up to just five of your GPIO pins
| (just power and I2C), the rest are free to diversify your
| project. The stacking header allows you to continue to
| use your existing HATs and add-ons with PiJuice._ " from
| https://uk.pi-supply.com/products/pijuice-standard
|
| But sure, some people/projects might prefer to shift the
| hardware to not be attached to the Pi. I wouldn't be
| surprised if you could find a product that does that too,
| or at worst I presume a basic plastic box (there's
| probably pre-made ones for the size of various Pi HATs?
| and of course 3D printing) and some fairly simple DYI
| wiring to connect the 5 pins through a cable wouldn't be
| too tricky.
| ryan-c wrote:
| This exists, and has monitoring, but won't do USB-PD:
| https://www.mini-box.com/OpenUPS
|
| There are, however, USB-PD sources that can run from a fixed
| voltage DC supply.
|
| I would actually really like something like this that can fit in
| my backpack with just shy of 100Wh (airline limit) of energy
| storage, a retractable cable to plug into an outlet, and
| monitoring via USB. In theory, I could build this myself around
| OpenUPS, but sourcing a pack, retractable cable and suitable
| enclosure is really annoying.
| dividedbyzero wrote:
| I'd also expect airport security to be quite a hassle with
| (partially) homemade electronics containing large batteries.
| brk wrote:
| It is surprisingly not. I travel frequently with random ESP32
| projects in various stages of looking highly suspicious and
| never get hassled about them. 4oz of an unfinished bottle of
| water though is absolutely not getting through security.
| dividedbyzero wrote:
| Do those have large li-ion batteries? Lets say you'd diy
| your own charge controller, I could see that get treated
| differently since you could cause a nasty fire that way.
| brk wrote:
| Not large, but they do often have some kind of battery.
| bick_nyers wrote:
| A nice 3D printed case and some fake branding would probably
| minimize any possible hassle.
| jdavis703 wrote:
| In London security will sometimes specifically ask if you
| or anyone else has made repairs or modifications to any
| electronics. Depending on how honestly you answer, this
| could still be a hassle.
| ryan-c wrote:
| The secret is to travel with such a large quantity of
| homemade electronics that you get classified as "harmless
| nerd".
| walterbell wrote:
| _> something like this that can fit in my backpack with just
| shy of 100Wh_
|
| This appears to fit the bill, if you can find it for sale,
| https://www.macworld.com/article/539605/zmi-powerpack-no-20-...
| & https://www.zmi.com/products/powerpack-
| no-20-qb826g-25000-ma...
|
| _> 90 watt-hour (Wh) / 25,000 milliampere-hour (mAh) battery.
| USB-PD + UPS: 5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/5A 100W MAX _
| joshspankit wrote:
| Andreas Spiess (and community) have put a lot of work in to this
| space as well. Feels like a good teamup.
| DarthNebo wrote:
| This is something one of my side projects aims to fix. Basically
| make a programmable battery source out of 18650 cells, USB
| Type-C, with automated charge & discharge control to keep it
| between 30-80% for UPS or Solar augmented use cases
| StuGoss wrote:
| Wouldn't stringing two USB power banks together effectively be a
| UPS for a Raspberry Pi?
| avidiax wrote:
| No, if they both have the cutout problem, they'll just cutout
| in sequence.
|
| You'd probably do better to have a supercapacitor or float
| charge a battery with an amenable chemistry between the power
| bank and the load.
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(page generated 2022-10-04 23:02 UTC)