Potential Issues of Using a USB Powerbank as a UPS (2021)

Weighed more than my MacBook, but indispensable. Too bad they don't make them anymore.

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.

And that's assuming you can even find a decent replacement battery.

Now, if you said the keyboard...

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).

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.

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.

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.

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)

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.

Raspberry Pis are common though. They've taken over like half of DIY electronics and home servers, for a good reason, everything else is way more hassle and less supported.

Not sure why you say PD is overcomplicated. Until you get above 30 to 60w where not everything supports it, stuff just works. Their only big mistake I see is not keeping the 12v power tier.

WAY too many things run on 12v and losing the ability to easily run legacy stuff sucked. But they'll fix that when 12v PPS trigger modules are available, for some reason they are not currently.

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.

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.

Most people want their devices to stay up and running on battery as long as they can, not just shut-down immediately after utility power goes down. Without somehow measuring the battery voltage, you can't estimate how much run-time your devices have to work with.

No.

Devices should survive powerloss, devices can have a graceful shutdown from an external source.

Key is in your "might".

If everyone were to charge a battery bank when the power is on, to see them through the time when it is off, the net result would be increased energy consumption, due to efficiency losses.

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.

If that's the case why do the lead acid batteries in consumer UPS's never last more than 3-5 years?

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

https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery...

more importantly, as the article suggests, it can be hard to know if the battery itself is powering the device while plugged in (while getting charged) or if there is a passthrough, a la laptop charger.

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.

Still a nice option!

https://smile.amazon.com/gp/product/B07T6LPP9W