Joe Schmoe
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UPS for Pi?

Wed Mar 25, 2015 10:56 pm

What is the best, small, cheap, UPS solution for a Pi?

That is, assume the following:
  1. You don't want to spend a lot of money (that is,more than about $20). Note that if you were willing to spend more than that, you'd just buy a regular, "mains" supply UPS, and plug your RPI's power supply into that. You want somethng at the Pi end (i.e., a battery of some sort).
  2. You, of course, want a battery that can be charged and be powering the Pi at the same time.
  3. You don't need very much off time - assume mostly just momentary power glitches. At most, say, 2 minutes of power outage is all that's needed.
  4. You don't need any fancy "shutdown the Pi if the power goes out" kind of circuitry/functionality. If the power does go out for "too long" and the Pi crashes, that's not the end of the world.
  5. You want something "off the shelf", not a custom (soldering involved) design/job.
I know this has been discussed at length on these boards for as long as the Pi has existed. I'm interested in what the endpoint of all those discussions is.
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

W. H. Heydt
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Re: UPS for Pi?

Thu Mar 26, 2015 12:07 am

Cheapest ones I know of are more like $40 to $50 (depending on where you buy).
This: http://www.newegg.com/Product/Product.a ... 6842102135 is the cheapest one Newegg lists and it's $40.
The lowest capacity one they list is this one: http://www.newegg.com/Product/Product.a ... 6842301434 but it's $55.

On the other hand, the first UPS I ever bought was a 1KVA unit in 1984 and it was $700 at the time. It's on about its 4th set of batteries. Very good capacity (3 x 30Ah, 12v), but a real bear to move as it weighs 80 lbs. UPSes have gotten smaller, lighter and cheaper (both relatively and absolutely) in the past 30 years.

Joe Schmoe
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Re: UPS for Pi?

Thu Mar 26, 2015 1:07 am

Cheapest ones I know of are more like $40 to $50 (depending on where you buy).
That's what I am trying to avoid. I suggest you go back and re-read the original post.

Yes, I realize that my prose is a bit turgid at times, but I assure you that it's all there.

Maybe the choice of terms "UPS" was not the best, since it seems to have put posters (such as yourself) on the wrong track. There should be another term for what I seek. In any case, I'm explicitly trying to avoid a "regular" ("mains" type) UPS. I want something at the 5V level.

I'm looking at something like:

www.adafruit.com/products/1566

But at $50, that's a bit more than I need, though I do find it cool.

There should be something like that that is less capable and less $$$.
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

ame
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Re: UPS for Pi?

Thu Mar 26, 2015 1:12 am

Joe Schmoe wrote:There should be something like that that is less capable and less $$$.
Here you go! It's half the price!
http://www.adafruit.com/products/1565

W. H. Heydt
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Re: UPS for Pi?

Thu Mar 26, 2015 1:29 am

Joe Schmoe wrote:
Cheapest ones I know of are more like $40 to $50 (depending on where you buy).
That's what I am trying to avoid. I suggest you go back and re-read the original post.

Yes, I realize that my prose is a bit turgid at times, but I assure you that it's all there.

Maybe the choice of terms "UPS" was not the best, since it seems to have put posters (such as yourself) on the wrong track. There should be another term for what I seek. In any case, I'm explicitly trying to avoid a "regular" ("mains" type) UPS. I want something at the 5V level.

I'm looking at something like:

www.adafruit.com/products/1566

But at $50, that's a bit more than I need, though I do find it cool.

There should be something like that that is less capable and less $$$.
I understood what you were saying just fine. My point was that, with your constraints--able to charge while running the Pi, minimal cost, not a DIY project--a small UPS is a reasonable solution, but not one that will come in under $20.

Even the Adafruit unit referenced just above (assuming it can be charged while it is being used) doesn't meet your price point.

Joe Schmoe
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Re: UPS for Pi?

Thu Mar 26, 2015 1:30 am

So, if somebody asked you for suggestions on getting a loaf of bread for less than $1, you'd just merrily suggest they buy your loaf that costs $3?
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

ame
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Re: UPS for Pi?

Thu Mar 26, 2015 1:32 am

Joe Schmoe wrote:So, if somebody asked you for suggestions on getting a loaf of bread for less than $1, you'd just merrily suggest they buy your loaf that costs $3?
It would depend on whether the original request was reasonable.

W. H. Heydt
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Re: UPS for Pi?

Thu Mar 26, 2015 2:13 am

Joe Schmoe wrote:So, if somebody asked you for suggestions on getting a loaf of bread for less than $1, you'd just merrily suggest they buy your loaf that costs $3?
Either that or laugh at them for having unrealistic expectations.

Joe Schmoe
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Re: UPS for Pi?

Thu Mar 26, 2015 2:50 am

Anyway, can we get this thread back on track?

Or do I need to create a new one?
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

ame
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Re: UPS for Pi?

Thu Mar 26, 2015 2:54 am

Joe Schmoe wrote:Anyway, can we get this thread back on track?

Or do I need to create a new one?
Here you go! It's half the price!
http://www.adafruit.com/products/1565

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bobstro
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Re: UPS for Pi?

Thu Mar 26, 2015 3:00 am

Joe Schmoe wrote:[...] I know this has been discussed at length on these boards for as long as the Pi has existed. I'm interested in what the endpoint of all those discussions is.
I can only speak to what my endpoint has been. I've been using a few different USB battery packs ranging from 7500 to 20000 mAh. One criteria that you might want to consider adding is the need to start or resume providing battery without any manual steps. Several (Anker, for one) require that you press a button to start the flow of power out the USB port, which is annoying if there's power outage. The winner for my purposes has been Limefuel, which simply start charging/powering whatever's attached. Unfortunately, their cheapest seem to run closer to $25. You can likely find one on sale somewhere. If you only need a few minutes power, this might be a solution.

I've done a little testing using a RPi with these, though mostly I run Android phones as cameras hung high up on my bird feeder where the damned squirrels can't reach.

Joe Schmoe
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Re: UPS for Pi?

Thu Mar 26, 2015 3:24 am

I can only speak to what my endpoint has been...
Thank you. That does look slick. And within range of my original $20 ballpark.

One question, though: It looks like this might only be able to supply 1A to the Pi, since (per another thread), isn't it the case that on these modern chargers, you need to do something special with the USB data pins in order to draw more than an amp? (Which the Pi, of course, does not do...)

Yes, 1A should be enough for the Pi, but you never know...
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

ktb
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Re: UPS for Pi?

Thu Mar 26, 2015 3:28 am

Sorry, OP. I'm not aware of anything that exactly meets your needs and price point. I did look around at many options. I use the Pico UPS and I like it. The cheapest version (without add-ons) is 19,50 + 6,43 VAT + 5,00 shipping = 30,93 Euro (33.93 US)

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solar3000
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Re: UPS for Pi?

Thu Mar 26, 2015 3:48 am

I've seen two Raspberry Pi specific UPS projects.
Here's one:
http://www.piups.net/
Antikythera

henryhanselscott
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Re: UPS for Pi?

Thu Mar 26, 2015 9:41 am

My solution uses 2 100 farad supercaps in series charged by a 5 volt supply through a diode and a 1 ohm power resistor. The supercaps actually charge to about 4.4 volts because of the diode drop. The supercaps charge feeds a DC boost convertor.

Boost convertor:
http://www.ebay.com/itm/3-pcs-XL6009-St ... 43c840c37f

supercaps:
http://www.ebay.com/itm/2pcs-New-Origin ... 3cedeb76ad

This combination has made the power to my Rpi brownout proof and is very stable. I am actually using a pic on the setup to signal the pi to start a shutdown procedure in the event that power goes out for more than 10 seconds, I know that that is beyond the scope of what you want.
I'm interested in what the endpoint of all those discussions is.
This solution is most certainly not that.

Henry

Joe Schmoe
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Re: UPS for Pi?

Thu Mar 26, 2015 10:17 am

This solution is most certainly not that.
Heh heh.

Somebody needs to take one of these solutions and package it up into something that can be mass-marketed...
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

ame
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Re: UPS for Pi?

Thu Mar 26, 2015 10:37 am

Joe Schmoe wrote:
This solution is most certainly not that.
Heh heh.

Somebody needs to take one of these solutions and package it up into something that can be mass-marketed...
Here you go! It's half the price!
http://www.adafruit.com/products/1565

Joe Schmoe
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Re: UPS for Pi?

Thu Mar 26, 2015 11:11 am

ame wrote:
Joe Schmoe wrote:
This solution is most certainly not that.
Heh heh.

Somebody needs to take one of these solutions and package it up into something that can be mass-marketed...
Here you go! It's half the price!
http://www.adafruit.com/products/1565
Are you mental?

How many times are you going to post this nonsense?
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

Bruny
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Re: UPS for Pi?

Thu Mar 26, 2015 11:11 am

Joe Schmoe wrote:
  1. You don't want to spend a lot of money (that is,more than about $20). Note that if you were willing to spend more than that, you'd just buy a regular, "mains" supply UPS, and plug your RPI's power supply into that. You want somethng at the Pi end (i.e., a battery of some sort).
not only that, but network switch could be used for powering multiple Pi 8-)

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bobstro
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Re: UPS for Pi?

Thu Mar 26, 2015 11:18 am

Joe Schmoe wrote:[...] One question, though: It looks like this might only be able to supply 1A to the Pi, since (per another thread), isn't it the case that on these modern chargers, you need to do something special with the USB data pins in order to draw more than an amp? (Which the Pi, of course, does not do...)
Most of the larger battery packs provide at least one a 2.1A output port. Some have ports designated for Apple or Samsung tablets, the Limefuel just has ports labeled 1A and 2A. Whether or not it outputs 2.1A all the time is something I haven't worried about. I'm sure some of the EE types would know in a heartbeat, but I'm just happy to plug a device in and have it run for hours.

I have used one of those cheap filter plugs that apparently provides the magic USB circuitry to allow a device to draw full power from a charger port even if not detected as the "right" type (e.g. a Samsung tablet can pull full power from an Apple port). It's sufficient to stop my Samsung from complaining. Not sure what it would do, if anything, for a RPi. When I bought mine, they were $3. At $8, it's probably worth it to build your own circuitry.

The Adafruit version seems to feature direct power without manually pushing a button, though it is a tad pricey for the capacity (1/3 the Limefuel). I'm sticking with Limefuel myself. I didn't find your requirements at all ambiguous. I'm personally looking out for a USB hub with a built-in battery with sufficient power off one or more charge ports to drive a RPi or cell phone. I'd like to use a better USB camera on my RPi for wildlife photography.

ame
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Re: UPS for Pi?

Thu Mar 26, 2015 11:41 am

Joe Schmoe wrote: Are you mental?

How many times are you going to post this nonsense?
You stated the Adafruit device would be ok, but it was too expensive. You did not acknowledge the smaller version, which meets your requirements and is closer to your target price.

JumpZero
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Re: UPS for Pi?

Thu Mar 26, 2015 11:58 am

Hi,
may be the word "UPS" was not appropriate. UPS: Uninterruptible Power Supply, usually refers to a set of rectifier/battery/inverter. This set has an AC input and an AC output. The pi input is DC. So the word battery or battery pack is more suitable. Even if technically a battery is an uninterruptible power supply.
--
Jmp0

jamesh
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Re: UPS for Pi?

Thu Mar 26, 2015 12:03 pm

Please keep calm people, or I will start editing the post I don't like out.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
"My grief counseller just died, luckily, he was so good, I didn't care."

Joe Schmoe
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Re: UPS for Pi?

Thu Mar 26, 2015 12:06 pm

JumpZero wrote:Hi,
may be the word "UPS" was not appropriate. UPS: Uninterruptible Power Supply, usually refers to a set of rectifier/battery/inverter. This set has an AC input and an AC output. The pi input is DC. So the word battery or battery pack is more suitable. Even if technically a battery is an uninterruptible power supply.
Right. That's the point. The term "UPS" refers both to a functionality (uninterruptible power) and to a specific type of implementation of that functionality. I thought the original post was clear enough that I was using the term in the first sense, but the nature of forums is that someone will always misunderstand...
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

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Djinny
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Re: UPS for Pi?

Thu Mar 26, 2015 2:04 pm

Skipped a bunch of posts.
Ok, there are usb battery packs for phones and such, that have both power in and power out ports.
That would probably work. Just plug the pi into the battery, and power into the batteries charge port, and there you go.

The charger will keep the battery charged and the battery will power the pi. and if the power goes out, the pi will continue to receive power from the battery. And would likely cost < $20
My RPi needs a fan, heat will leech into the battery, so people saying I don't need a fan, don't understand how Li-Po batteries are affected by high temps. Cool pi = cool battery.
I would very much so like to see a Pi2/Pi3 Zero, power and size.

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