mikerr
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Re: Raspberry Pi Zero power consumption

Thu Dec 03, 2015 11:04 am

As a baseline, PiZero uses 54ma with no SD card inserted
daveake wrote:Another way of reducing power consumption is to reduce the voltage that the Pi Zero runs from. [3.3v]
3.3v uses less power for sure.

Oddly I found very little difference (+/- 1ma) powering 3.3v into the 5V GPIO (pin2) vs 3.3v into 3.3v GPIO (pin1)
-surely the latter should be less as it's bypassing a regulator ?
Last edited by mikerr on Thu Dec 03, 2015 12:41 pm, edited 1 time in total.
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TimG
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Re: Raspberry Pi Zero power consumption

Thu Dec 03, 2015 12:40 pm

daveake wrote:The lowest PSU voltage that the my Pi Zero reliably boots from is 2.9V
Dave, have you measured the drop-out of the regulator at these low voltages? Is there anything to be gained by shorting the 3.3V rail to the 5V rail?

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davidcoton
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Re: Raspberry Pi Zero power consumption

Thu Dec 03, 2015 4:59 pm

TimG wrote: Is there anything to be gained by shorting the 3.3V rail to the 5V rail?
Yes. A much higher likelihood of destroying a Pi by forgetting the link and applying 5V :lol: :D :shock: :roll: :twisted: :oops:
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TimG
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Re: Raspberry Pi Zero power consumption

Fri Dec 04, 2015 3:29 am

TimG wrote:Dave, have you measured the drop-out of the regulator at these low voltages? Is there anything to be gained by shorting the 3.3V rail to the 5V rail?
OK I measured it and the regulator drop-out is very small, about 5mV at 3.0V and 94mA.

I also measured the current draw and got virtually the same numbers as dakeake:
67mA @ 5.0V
89mA @ 3.3V
(tvservice off, LED off, CPU idle)

The LED draws an extra 2.3mA, and HDMI another 18mA.

m-h
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Raspberry Pi Zero driven from Lithium ion directly

Tue Mar 22, 2016 11:20 pm

daveake wrote:The lowest PSU voltage that the my Pi Zero reliably boots from is 2.9V

After reading a lot of warnings on bad USB power supplies over the years, and then this thread , I was confused on the real power needs of the pi . Specifically the pizero. But if daveake and others can run the pi from 3 volts mine should be able to do that too.
So I ran a few tests powering the pizero direct from a lithium-ion cell , including the pimoroni phat dac and a cheap wifi dongle.
And after optimizing the USB cable between cell and pi I must conclude it is a functional setup that does not impact the sound quality to much to be easy detectable in the range 4.2 to 3.0 volts.
Below 2.9 volts ( measured on the GPIO pins 2 and 6 ) Wifi activity is noticeable in the audio output, and streaming stutters.
How ever I could boot the pi with 2.83 volts, and 'run' it up to 2.75 volts , about where it reboots and music was no longer bearable.

This powering method might be of interest to people squeezing the last miliwatts out of their pi setup, when forced to run on batteries and reduce weight.

My first tests were done with a 1 cell ( 18650 ) usb charger to find I could stream music for 5 hours and about 40 minutes before the first reboot.
Next runtime test should be with the exact same cell but without the DC-DC step up regulator. And see how much I do gain from the missing step up regulator and the improved overall efficiency from running on lower voltages.
But of course it must still produce music that does not sound bad.
After that, I will power off the HDMI and the hungry led too to measure that extra saving.
Perhaps under clocking the processor and RAM will help to save even a bit more, so feel free to suggest options for that.

I fed the power though the micro USB for convenience , direct to GPIO should be a bit more efficient..
And even my Bplus with cirrus logic audio card ran well 'way' below 3.2 volts to help drain the cells faster.

Disclaimer.
Do not take my experiences as the truth, but also do not repeat it if you are not willing to risk to fry your pi.
This is completely outside the designed operating range of the pi, and is pure experimental.
So do not ask me why your pi does not run on your power supply of x milliamp.

Thanks to the foundation for providing is this great little wonder for education of students of all ages.

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rpdom
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Re: Raspberry Pi Zero power consumption

Wed Mar 23, 2016 1:52 am

Running a Lithium-Ion cell down to below about 3.2V can seriously damage the cell.

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ouafnico
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Re: Raspberry Pi Zero power consumption

Wed May 25, 2016 1:03 pm

Hi guys,
Has anyone tried or can try to mesure the consumption of Pi zero with the raspi camera module?

I'm studying how to make the Pi Zero running on battery/solar with Wifi dongle and camera module.

occupied
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Re: Raspberry Pi Zero power consumption

Wed May 25, 2016 1:12 pm

ouafnico wrote:Hi guys,
Has anyone tried or can try to mesure the consumption of Pi zero with the raspi camera module?

I'm studying how to make the Pi Zero running on battery/solar with Wifi dongle and camera module.
Not yet, but I should have within the next few days or so.
I currently run a Pi 2B from a 10,400 mAh power bank, recording from the camera module. I get around 26 hours when I disable the non-essentials.
I'm looking forward to seeing what the Pi Zero can do when it arrives.

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ouafnico
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Re: Raspberry Pi Zero power consumption

Wed May 25, 2016 1:16 pm

occupied wrote:
ouafnico wrote:Hi guys,
Has anyone tried or can try to mesure the consumption of Pi zero with the raspi camera module?

I'm studying how to make the Pi Zero running on battery/solar with Wifi dongle and camera module.
Not yet, but I should have within the next few days or so.
I currently run a Pi 2B from a 10,400 mAh power bank, recording from the camera module. I get around 26 hours when I disable the non-essentials.
I'm looking forward to seeing what the Pi Zero can do when it arrives.
Thanks :)

I got a lipo rider pro, with 2000mah battery, and two solar panel (above 3,5W), I will try how many time I can get, but not a lot I assume :?

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Re: Raspberry Pi Zero power consumption

Mon May 30, 2016 7:51 am

You can see the results of my initial test here

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alexeames
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Re: Raspberry Pi Zero power consumption

Mon May 30, 2016 8:24 am

ouafnico wrote:Hi guys,
Has anyone tried or can try to mesure the consumption of Pi zero with the raspi camera module?

I'm studying how to make the Pi Zero running on battery/solar with Wifi dongle and camera module.
Image

Image

http://raspi.tv/2016/raspberry-pi-zero- ... ith-camera
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joe7dust
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Re: Raspberry Pi Zero power consumption

Tue Jun 07, 2016 8:42 am

A little birdie told me that you are all full of it, and that the Pi Zero will not even run off of 3.7v let alone 2.9 to 3.3

Is there a link to some proof on which party is actually correct on this subject?
I'm just curious. ;)

Fortunately for me I was able to pick up a DC-DC booster for just $3 and some change instead of the $20 + $9 shipping model that is recommended for running it off a cellphone battery so regardless of the answer it isn't going to cost me a huge chunk of money or anything now like I thought it would before.

texy
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Re: Raspberry Pi Zero power consumption

Tue Jun 07, 2016 9:25 am

joe7dust wrote:A little birdie told me that you are all full of it, and that the Pi Zero will not even run off of 3.7v let alone 2.9 to 3.3

Is there a link to some proof on which party is actually correct on this subject?
I'm just curious. ;)

Fortunately for me I was able to pick up a DC-DC booster for just $3 and some change instead of the $20 + $9 shipping model that is recommended for running it off a cellphone battery so regardless of the answer it isn't going to cost me a huge chunk of money or anything now like I thought it would before.
Actually that post was in error on my part - I had no idea this was even possible.
It is certainly not recommended for beginners, or in cases where peripherals require a 'good' 5v power source.
Also please be a bit more friendlier with your language - that does go against the forum rules.
Quite clearly these people know what they are doing - you are more or less telling them they are lying.
Texy
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https://www.raspberrypi.org/forums/viewtopic.php?f=93&t=147682#p971555

mikerr
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Re: Raspberry Pi Zero power consumption

Tue Jun 07, 2016 9:36 am

Here's my pi zero running directly off 3.3v:

Image

it continues to work down to 3.1v. YMMV
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joe7dust
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Re: Raspberry Pi Zero power consumption

Tue Jun 07, 2016 10:31 am

I hope these guys know I was speaking tongue in cheek in my reply. I definitely wasn't trying to insult or accuse anyone here of actually lying.

I'd be interested in trying that setup actually if I found a display that also ran off 3.3v. It was a feat in itself just to find one that runs off 5v.

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Re: Raspberry Pi Zero power consumption

Tue Jun 07, 2016 10:53 am

[quote=mikerr]Here's my pi zero running directly off 3.3v:[/quote]
My school proxy wont allow me to visit imugrr :( Will have to look at hows that works from home.

This is a really interesting thread. I 'downgraded' the computer in my solar powered shed from a Pi2 to a Pi0 for power reasons. I want to keep my shed up and running 24/7/365.

It has wifi, a camera module and environmental sensors attached.

To save power I can shut down the wifi, turning it back on from time to time to transmit recorded environmental data to a website.
Visiting a webpage on a Pi in the house will trigger a 433 MHz transmitter. This sends a signal to shed pi to turn on wifi and stream video.

Hypothetically, could I run my Pi 0 from 3V when it is only monitoring environmental sensor data, and only kick in the 5V supply when I am going to use Wifi?

texy
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Re: Raspberry Pi Zero power consumption

Tue Jun 07, 2016 11:34 am

mikerr wrote:Here's my pi zero running directly off 3.3v:

Image

it continues to work down to 3.1v. YMMV
So that's connecting the bench supply to 3.3v on the GPIO port?

On another slightly off-topic note. The Pi 'knows' that the input voltage is as it can trigger the 'rainbow' square on the output, but is the voltage value accessible?

Texy
Various male/female 40- and 26-way GPIO header for sale here ( IDEAL FOR YOUR PiZero ):
https://www.raspberrypi.org/forums/viewtopic.php?f=93&t=147682#p971555

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davidcoton
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Re: Raspberry Pi Zero power consumption

Tue Jun 07, 2016 11:38 am

morphy_richards wrote:Hypothetically, could I run my Pi 0 from 3V when it is only monitoring environmental sensor data, and only kick in the 5V supply when I am going to use Wifi?
What happens is that the 5V supply powers USB (and, I think, HDMI) directly, while everything(?) else runs from an on-board regulators at 3V3 or less. So below 5V supply, USB and HDMI may give problems. Below about 3V5, anything running at 3V3 may start to misbehave. The core runs at less voltage, so that will continue until something else prevents it (I don't know the actual limit at which something critical will stop -- or whether there is even anything critical on the 3V3 supply.) However, attempting to switch supply voltages may cause other problems, like back voltages into your external 3V, or switching glitches. These could do serious harm -- or it might all "just work". Experiment at your own risk. The regulators are fairly efficient, so I doubt you will save much power by reducing the supply voltage. There's more mileage in disabling unused peripherals (but even then not much on a Zero).
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dgordon42
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Re: Raspberry Pi Zero power consumption

Tue Jun 07, 2016 11:54 am

texy wrote:The Pi 'knows' that the input voltage is as it can trigger the 'rainbow' square on the output, but is the voltage value accessible?
No, the low voltage warning is triggered if the 5V supply drops below a reference internal 4.65V level. The Pi does not know the actual power supply voltage.

Dave.

texy
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Re: Raspberry Pi Zero power consumption

Tue Jun 07, 2016 12:17 pm

OK - cheers. I guess it would of been brought up before if it was possible anyway.
Texy
Various male/female 40- and 26-way GPIO header for sale here ( IDEAL FOR YOUR PiZero ):
https://www.raspberrypi.org/forums/viewtopic.php?f=93&t=147682#p971555

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rpdom
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Re: Raspberry Pi Zero power consumption

Tue Jun 07, 2016 6:39 pm

I don't think the Zero even has the low-voltage detector circuit.

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ouafnico
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Re: Raspberry Pi Zero power consumption

Wed Jun 29, 2016 9:00 am

Hi,

The pi Zero, with pi cam (v1.2), a wifi module, and motioneye running (50 to 90% CPu usage), give me above 475mA/h.

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ouafnico
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Re: Raspberry Pi Zero power consumption

Sat Jul 02, 2016 12:59 pm

With a real multimeter:

Pi0 with wifi dongle: 90 to 130 mA.
Pi0 with wifi dongle + raspi camera module (1.2) + motioneye running (~90% CPU usage) : 300-320mA

peterlite
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Re: Raspberry Pi Zero power consumption

Tue Nov 15, 2016 12:13 am

my Charger Doctor is going to go the way of the dodo
You are feeding it to a Dutch sailor? :D

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KevinA
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Re: Raspberry Pi Zero power consumption

Mon Mar 26, 2018 2:59 pm

Has anyone tried the latest generation of Pi's?
PI Zero W and PI 3+?
I have a USB voltage/amp device that shows the PI Zero W at 20ma, no SD. My PI 3 with Logitech K400+ receiver and HDMI connected is at 307ma.
The $1.89 tester https://goo.gl/Mj3BCL

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