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eastpole
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Re: RasPi power usage measurements ~2 watts at idle

Thu Dec 27, 2012 5:00 am

ivanohé wrote:I've read that new model uses 0.12W when halted. That's great....
Can anyone confirm this? For some purposes 0.5 W vs. 0.12 W makes no difference, but for some purposes (or for sizing a micro UPS) it does. Thanks for any info!

eastpole

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alexeames
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Re: RasPi power usage measurements ~2 watts at idle

Thu Dec 27, 2012 9:23 am

eastpole wrote:
ivanohé wrote:I've read that new model uses 0.12W when halted. That's great....
Can anyone confirm this? For some purposes 0.5 W vs. 0.12 W makes no difference, but for some purposes (or for sizing a micro UPS) it does. Thanks for any info!

eastpole
I'll measure it now I have a Rev 2, but it won't be today. :D Feel free to PM me in a day or two if I forget. :D
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dom
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Re: RasPi power usage measurements ~2 watts at idle

Thu Dec 27, 2012 11:49 am

ivanohé wrote:I've read that new model uses 0.12W when halted. That's great, because I was looking for a remote controlled switch.
So it would be completely usefull if the pi could be awaken from halt state, is it possible ?
It can now be woken through GPIO.
http://www.raspberrypi.org/phpBB3/viewt ... 29&t=24682

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Jim JKla
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Re: RasPi power usage measurements ~2 watts at idle

Thu Dec 27, 2012 11:55 am

It's the energy used by the little demon running around switching off all the lights before he goes to bed. :mrgreen:
Noob is not derogatory the noob is just the lower end of the noob--geek spectrum being a noob is just your first step towards being an uber-geek ;)

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Re: RasPi power usage measurements ~2 watts at idle

Thu Dec 27, 2012 8:14 pm

dom wrote:
ivanohé wrote:I've read that new model uses 0.12W when halted. That's great, because I was looking for a remote controlled switch.
So it would be completely usefull if the pi could be awaken from halt state, is it possible ?
It can now be woken through GPIO.
http://www.raspberrypi.org/phpBB3/viewt ... 29&t=24682
Yeah I tried this the other day with a reset switch - it works a treat.
http://raspi.tv/2012/making-a-reset-swi ... spberry-pi

It can also be done remotely with a relay, but that would need to be powered by another device that is powered up. :lol:
http://raspi.tv/2012/the-self-resetting-raspberry-pi
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Re: RasPi power usage measurements ~2 watts at idle

Thu Dec 27, 2012 8:51 pm

eastpole wrote:
ivanohé wrote:I've read that new model uses 0.12W when halted. That's great....
Can anyone confirm this? For some purposes 0.5 W vs. 0.12 W makes no difference, but for some purposes (or for sizing a micro UPS) it does. Thanks for any info!

eastpole

OK measurements on a Rev 2 Pi (Sept Raspbian, updated) as follows...
5.05V, 0.40A booting
5.07V, 0.12A once shutdown.

Trying it with the latest and greatest December Raspbian...
5.05V, 0.40A booting
5.07V, 0.12A once shutdown.

It still looks like half a watt, but it's possible that I'm getting close to the limitations of my measuring device.
Alex Eames RasPi.TV, RasP.iO

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Re: RasPi power usage measurements ~2 watts at idle

Tue Jan 08, 2013 9:03 pm

Does anyone know what the cost per year would be to run the raspberry pi 24/7?

Currently paying 11p per unit with EDF electricity but I have no idea how to work out the calculation :geek:
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Re: RasPi power usage measurements ~2 watts at idle

Tue Jan 08, 2013 9:21 pm

At 11p per unit, you can reckon £1.00 per year per watt. 2 quid a year for a headless model B. The upcoming model A without the greedy LAN9512 chip - less than half of that.
Don't judge Linux by the Pi.......
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Re: RasPi power usage measurements ~2 watts at idle

Tue Jan 08, 2013 9:31 pm

For the sad gits out there the maths works like this :
A unit is a kilowatt hour (kWh) which is 1 watt for 1000 hours (or 1000 watts for one hour). A thousand hours translates to 42 days give or take. There are about 9 * 42 days in a year (again give or take) So 1 watt needs 9 kWh per year and at 11p per kWh it comes out at 99p (give or take). The Pi using give or take 2 watts will come to £2 a year give or take........
Don't judge Linux by the Pi.......
I must not tread on too many sacred cows......

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Re: RasPi power usage measurements ~2 watts at idle

Tue Jan 08, 2013 10:00 pm

Thanks yes I managed to work it out just after I posted as well.

Amps rating = 0.20 Amps
Voltage Rating = 12.5 Volts
Watts = 2.5 Watts
kilowatts = 0.003 kW
Hours used in month = 720 Hours
Kilowatt Hours = 2.16 kWh
Electricity price per Unit or Kwh = 11 pence
Cost (in pence) to run the Item for 1 month = 23.76 pence
Cost in £'s to run Item for 1 month = £0.238 pounds
Cost in £'s to run Item for a year = £2.85 a year

:geek:
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Re: RasPi power usage measurements ~2 watts at idle

Wed Jan 09, 2013 6:15 am

alexeames wrote: Here's the setup.
Power source 3 cell lipo (12.5v)
Connected to Hyperion E-meter calibrate shunt (and then on to emeter)
Connected to LM2596S switching reg (allegedly 90% efficient) stepping voltage down to 5.0V
Hello alexeames,

Could you please post the circuit diagram you used to step down 12.5 volt to 5.0V using LM2596S switching reg?

Thanks,
Simon Mandy
http://raspisimon.no-ip.org
Raspberry Pi Model B x 2, Raspberry Pi 2 x 2, Transcend 32GB Class 10, Transcend 16GB Class 10, Transcend 8GB Class 4, Custom 12V 1.5A (stepped down to 5.5V)

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Re: RasPi power usage measurements ~2 watts at idle

Wed Jan 09, 2013 8:20 am

sim_tcr wrote:
alexeames wrote: Here's the setup.
Power source 3 cell lipo (12.5v)
Connected to Hyperion E-meter calibrate shunt (and then on to emeter)
Connected to LM2596S switching reg (allegedly 90% efficient) stepping voltage down to 5.0V
Hello alexeames,

Could you please post the circuit diagram you used to step down 12.5 volt to 5.0V using LM2596S switching reg?

Thanks,
Simon Mandy
Sorry I can't help with the circuit, I use one of these...
Image

http://www.ebay.co.uk/itm/251105572041? ... 1423.l2649

I know from your other thread that you can't do ebay, so that's not much help :(
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Re: RasPi power usage measurements ~2 watts at idle

Wed Jan 09, 2013 8:38 am

If you break into the +5 volts going to the RasPi you can just connect your multimeter in current measuring mode. You know it's at 5 volts so power is simply 5 x amps reading. No need to worry about efficiency of your psu then. :D
There are few rewards greater than accomplishing a difficult task. Just because something doesn't cost money doesn't mean there is no cost. Every success makes the next one easier. Of course that takes determination and patience.

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Re: RasPi power usage measurements ~2 watts at idle

Wed Jan 09, 2013 3:26 pm

alexeames wrote:
sim_tcr wrote:
alexeames wrote: Here's the setup.
Power source 3 cell lipo (12.5v)
Connected to Hyperion E-meter calibrate shunt (and then on to emeter)
Connected to LM2596S switching reg (allegedly 90% efficient) stepping voltage down to 5.0V
....
...
Sorry I can't help with the circuit, I use one of these...
Image

http://www.ebay.co.uk/itm/251105572041? ... 1423.l2649

I know from your other thread that you can't do ebay, so that's not much help :(
not sure if the ebay issue still applies here but you can try here:
http://www.goodluckbuy.com/index.php?ta ... S+&x=0&y=0

cheap and free delivery

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Re: RasPi power usage measurements ~2 watts at idle

Tue Feb 05, 2013 10:27 pm

Since there's a new kid in town, the model A, I thought I'd do some measurements :)

Nothing plugged in at all except an Edimax wifi dongle.
while booting 5.07V and 0.17A
while wifi starting up 5.05V and 0.24A
once settled 5.07V and 0.16A

So, with an Edimax wifi dongle present, the model A idles along using 0.81 Watts. I'll have to look up the thread to see how much the Edimax is using - or I could do a delayed shutdown and pull the Edimax - that's a better idea.

After pulling the Edimax it went from 0.16A to 0.10A, which means with nothing at all plugged in, it's using 0.507 Watts.

Now, if we were to change the regulators... ;) (we've had that discussion before LOL)
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Re: RasPi power usage measurements ~2 watts at idle

Tue Feb 05, 2013 10:49 pm

you doing it wrong using 12 volt you should be using 5v volt and mesure between the ubec and the rpi
zag wrote:Thanks yes I managed to work it out just after I posted as well.

Amps rating = 0.20 Amps
Voltage Rating = 12.5 Volts
Watts = 2.5 Watts
kilowatts = 0.003 kW
Hours used in month = 720 Hours
Kilowatt Hours = 2.16 kWh
Electricity price per Unit or Kwh = 11 pence
Cost (in pence) to run the Item for 1 month = 23.76 pence
Cost in £'s to run Item for 1 month = £0.238 pounds
Cost in £'s to run Item for a year = £2.85 a year

:geek:

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Re: RasPi power usage measurements ~2 watts at idle

Tue Feb 05, 2013 10:57 pm

dasimpson wrote:you doing it wrong using 12 volt you should be using 5v volt and mesure between the ubec and the rpi
Depends what he wants to measure doesn't it? If he wants to know how much electricity it will take to run the pi using a regulator, so he can work out the cost, it makes sense to measure the input side of the regulator. If he's only interested in how much the Pi itself consumes, your way would be correct.
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Re: RasPi power usage measurements ~2 watts at idle

Tue Feb 05, 2013 11:00 pm

to his first post that would be to how much the pi uses
oops i stand corrected he was lookingto see how much everything would use late night reading to many posts thats my excuse lol
he had still done it wrong as he dident take the reading of what the mains tranformer was using also
Last edited by dasimpson on Tue Feb 05, 2013 11:10 pm, edited 2 times in total.

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Re: RasPi power usage measurements ~2 watts at idle

Tue Feb 05, 2013 11:03 pm

i just wish my self that li-ions were 5 volt and not 3.7 then i wouldent have to use a dc boost converter wasting over half the power the batterys store

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Re: RasPi power usage measurements ~2 watts at idle

Mon Feb 18, 2013 10:21 pm

alexeames wrote:Since there's a new kid in town, the model A, I thought I'd do some measurements :)

Nothing plugged in at all except an Edimax wifi dongle.
while booting 5.07V and 0.17A
while wifi starting up 5.05V and 0.24A
once settled 5.07V and 0.16A

So, with an Edimax wifi dongle present, the model A idles along using 0.81 Watts. I'll have to look up the thread to see how much the Edimax is using - or I could do a delayed shutdown and pull the Edimax - that's a better idea.

After pulling the Edimax it went from 0.16A to 0.10A, which means with nothing at all plugged in, it's using 0.507 Watts.
Same experiment as above, but with a Dynamode dongle that gets quite hot in use.
5.03V 0.19A while booting
5.03V 0.28A with wifi on
5.03V 0.12A with wifi dongle pulled out
5.05V 0.04A when halted

So the Dynamode dongle uses 0.16A (and wastes a lot of it as heat), whereas the Edimax only uses 0.06A. I know which I prefer for a low power Pi ;)
Alex Eames RasPi.TV, RasP.iO

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Re: RasPi power usage measurements ~2 watts at idle

Sun Jun 09, 2013 9:01 pm

Thought I'd add some measurements with a model A and a camera board.

This is powered with a 3 cell lipo and 85% efficient switching reg. The measurements are made directly from the battery, as my PiCamcorder has a reg inside the case. The wattage measurements are what is coming out of the battery, whereas to correct to what is actually being used by the Pi you need to multiply by 0.85.

So, with a model A, and Edimax wifi dongle and a RasPiCam (+ bluetooth serial adaptor + additional LED) attached...
Idle: 12.16V, 0.10A = 1.21 Watts at battery ~ 1.03 Watts at the Pi
Recording video: 12.13V, 0.24A = 2.91 Watts at battery ~2.47 Watts at the Pi

Removed Edimax & rebooted
Idle: 12.14V, 0.08A = 0.97 Watts at battery ~ 0.82 Watts at the Pi
Recording video: 12.13V, 0.21A = 2.54 Watts at battery ~ 2.16 Watts at the Pi

After shutdown
12.14V, 0.04A = 0.49 Watts at battery ~ 0.42 Watts at the Pi

So, the camera uses about 1.4 Watts when recording video (1080p25)
and the model A + camera working hard uses about as much "juice" as a model B working hard.
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Re: RasPi power usage measurements ~2 watts at idle

Sun Sep 22, 2013 12:43 am

Hello, I need to battery power an RPi for days/weeks. With a battery of 60Wh or so it would be possibile for my project with RPi in halt state, woken up only for minutes a day during its use. I read that RPi doesn't have a sleep or low power mode, but it can halt and can wake up thru GPIO.
...and now the burning question: would it be possibile to halt and than wake up without going thru system reset/reboot? I need to emulate a sleep mode, a temporary suspension of the operations and the a wake up with the continuation of OS and process run.

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Re: RasPi power usage measurements ~2 watts at idle

Sun Sep 22, 2013 8:08 am

It might be, but it's above my skill level. Also I haven't heard of anyone doing this yet.

The problem, I think, is that when the model B is powered up, (even in a shutdown state) the network chip still uses quite a bit. You can make that go away by using a model A as it doesn't have that chip.

Perhaps some kind of microcontroller-switch combo could be used for a timed hard cut-off after shutdown (I know this isn't what you're after though).
Last edited by alexeames on Wed Jan 01, 2014 6:07 pm, edited 1 time in total.
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Re: RasPi power usage measurements ~2 watts at idle

Sun Sep 22, 2013 8:49 am

I haven't (yet) found a way to halt and restart as per a true sleep mode - let me know if you find it.

The solution I came up with was to design the Sleepy Pi board which implements a virtual sleep mode. It is essentially an Arduino processor, a real-time clock and a power switch. It enables you to boot up and shutdown the Raspberry Pi whenever you want, so it's ideal for the application where you want to boot up for a few minutes and then "Sleep" the rest of the time. You need to work the software on the RPi so that any states you need are preserved across boots.

The board is in Beta test at the moment, and updates can be found at http://www.spellfoundry.com
Sleepy Pi - Extend RPi battery life with a plugin Power Management & Arduino I/O board
http://www.spellfoundry.com

wildstray
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Re: RasPi power usage measurements ~2 watts at idle

Sun Sep 22, 2013 11:09 am

I bought Model A, I don't need networking but only to write pictures and videos on SD.
SleepPi is really interesting (and, let me say, a bit expensive...) but my problem is that I cannot wait at least 10s of boot time to have RPi ready. I don't need RPi always on, but I need RPi "always ready" :) My project involves a PIR sensor and I need to start taking from camera in milliseconds from trigger...

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