7 ms·

Raspberry Pi Zero Power Consumption Comparison

59 points by geerlingguy 11y ago

geerlingguy 11y ago
Just posting the tl;dr at the top of the article: The Raspberry Pi Zero uses about 1/3 the power of the A+, or 1/6 the power of the model 2 B. This is pretty awesome, as it's only about twice the power usage of a typical Arduino setup, so battery-powered embedded projects can start considering the Pi as an option. It helps, of course, that this is just $5! I just got my mini-HDMI adapter in the mail today, so I'll be running a few more tests to see if there are any other major differences between the Zero, the model 2 B, and the A+/B+ (I currently use the A+ for most small projects right now, and the 2 B when I need a little more CPU).
- swiley 11y ago
  The power consumption was the number 1 reason I couldn't use the PI in most of my projects so this is super exciting (the number 2 being cost).
  - throwawydfje 11y ago
    if power and cost were 1 and 2 this is pretty good for you! Could I ask what the specific applications were? I'm very interested and wonder what other people have done. May have follow-up questions for you :)
- geerlingguy 11y ago
  I may also disable the HDMI interface as well, to see if it makes any real difference in power consumption. It's rumored to do so, but I haven't seen any proof that it helps. It can be disabled with the command: /opt/vc/bin/tvservice -o
  - geerlingguy 11y ago
    Can't edit this post anymore, but I'll reply here: I just ran tests with HDMI disabled, and it looks like it does save ~30 mA. Running more tests, will leave a top-level comment with more notes soon.
pen2l 11y ago
> The Raspberry Pi Zero - quite a small Linux computer! Okay, I have a smalllll complaint. In popular modern-day English, R-pi is not really a 'computer'. Because you can't run a full-fledged operating system like Windows or Linux on it -- you have to run embedded version of those OSs (like Windows CE or whatever). I think I may not be totally and technically correct in my point here, but I think it's an important point to make or at least mention somewhere along the way anyway -- because, as it happens, I told someone that R-pi is basically a cheap computer... and this person was eventually miffed to find that he couldn't run the Windows applications he wanted to run on it, because those applications only could run on a x86 Windows install.
- pjc50 11y ago
  The solution to "cheap windows" is the various Bay Trail devices; so far the best offer I've seen is 7" tablet for £45 which comes with a year's subscription to Office 365 (worth >£50).
  - hobbsy 11y ago
    do you have a link please?
    - pjc50 11y ago
      http://www.amazon.co.uk/gp/product/B00O636WJU http://www.amazon.co.uk/gp/product/B00O636WJU (price has gone up a bit)
  - dogma1138 11y ago
    Tablets are usually locked tight. You can get the NUC board DE3815TYBE for under 100$ these days and it's completely open.
- mikeash 11y ago
  The problem is not people calling the RPi a "computer" (which it absolutely is), the problem is people who think "computer" means "Windows PC."
- 11y ago
throwawydfje 11y ago
Very interesting. Still far from solar-powered territory for outdoor projects, for example. Unless there were a way to wake the pi very easily. However, the raspberry pi includes no power management whatsoever; it's either off or on[1]. Why not? Does the chip not support it? --> Note that the article specifically calls out disabling USB, disabling ethernet (not relevant here), and disabling video output if not using it. I wonder if the author could try disabling HDMI to see if power is reduced.... This can be mitigated if there were a way to boot quickly on demand. See this writeup on sleepypi, an expansion-board that does just that:[2] So it should be possible to wake on demand by powering up and going through a boot cycle. Since the hardware is SO very fixed (not going to change short of ripping parts of the board off) I wonder why the boot time couldn't be further reduced...what really takes 10 seconds, during which the SD card could have read 200 MB or so? It's nearly enough time to wake from hibernation, were that supported. (SD card bus speed is limited to reading 20 MB/second or so). I'm sure it could be improved. This other write-up mentions using the previous generation for up to 24 hours for remote-location time-lapse photos [3] - also contains an interesting idea about underclocking. Not sure if this suggestion is relevant, possible, or works. [1] No sleep mode on pi: http://raspberrypi.stackexchange.com/questions/4773/raspberry-pi-sleep-mode-how-to-avoid http://raspberrypi.stackexchange.com/questions/4773/raspberr... [2] * Pi and SleepyPi: http://marktmarshall.com/2014/08/experimenting-with-raspberry-pi-power-management/ http://marktmarshall.com/2014/08/experimenting-with-raspberr... * An interesting FAQ on SleepyPi: http://spellfoundry.com/sleepy-pi/sleepy-pi-faq/ http://spellfoundry.com/sleepy-pi/sleepy-pi-faq/ [3] Powr saving on raspberry pi A in remote installations: http://babaawesam.com/2014/01/24/power-saving-tips-for-raspberry-pi/ http://babaawesam.com/2014/01/24/power-saving-tips-for-raspb...
- bootload 11y ago
  " I wonder if the author could try disabling HDMI to see if power is reduced...." from comments ~ http://www.midwesternmac.com/comment/3216#comment-3216 http://www.midwesternmac.com/comment/3216#comment-3216 in this article, "Controlling both the PWR and ACT LEDs on the Raspberry Pi 2" ~ http://www.midwesternmac.com/blogs/jeff-geerling/raspberry-pi-zero-power http://www.midwesternmac.com/blogs/jeff-geerling/raspberry-p...
mike-cardwell 11y ago
I'd really like to find a USB battery pack for one of these which can be used to make the device portable. I know there are loads, but they usually have one or more of the following problems: 1.) Can't power the PI at the same time as being charged 2.) PI consumes power faster than the battery can charge up 3.) Neither of the above two problems, but when you plug the battery into the mains it momentarily disrupts the PI causing it to reboot. Anyone know of a battery which will last with one of these for the best part of a day or more and which I can just plug into the mains when I'm near a socket to keep it topped up? [edit] FWIW, my plan (if I can sort the power) is to migrate my email and xmpp services from the fixed in place Intel NUC under my TV at home, to a Pi Zero in my backpack.
- bapbap 11y ago
  I am not a battery or electronics expert but my understanding is that it is not ideal to simultaneously charge and discharge a LiPO battery, so most don't support passthrough. I use a RAVPower Xtreme (26800mAh - though I'm not sure if I believe that rating) to power a dashcam and had similar requirements to you. However, I've implemented a DPDT relay and a 12V boost regulator to switch between the battery pack and car power (ACC), depending on the ignition status of the car. So when the car is on, the battery is being charged only and the dashcam is getting power from the car. When the car is off, the battery is only being used to power the dashcam. I've not tested it with a Pi but there is not an interruption in power long enough to disturb the dashcam (the relay spec is 8ms operate time). The battery pack is charged using a 2A 5V charger. I can't properly assess the charge status/history of the battery as it only has 4 LED's and I don't want to take it apart but so far my commute and other driving is long enough to keep it ticking over.
  - disposeofme123 11y ago
    Its definitely possible, think about the circuitry in your phone and how the batteries work with that. As far as I'm aware, most modern phones can't turn on without a battery pack present in the phone, even when plugged in, which would suggest that the juice is actually coming from the phone battery at all times and not direct from the charger regardless of charging state.
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geerlingguy 11y ago
Just did a bunch more testing, and I can get it to idle at ~40 mA if I disable HDMI (inside `/etc/rc.local`: `/usr/bin/tvservice -o`). With a WiFi dongle (so it can operate on the local network at least) and HDMI disabled, it hovers around 120 mA. Very, very nice!
- deleted 11y ago
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59 points by geerlingguy 11y ago

Just posting the tl;dr at the top of the article: The Raspberry Pi Zero uses about 1/3 the power of the A+, or 1/6 the power of the model 2 B. This is pretty awesome, as it's only about twice the power usage of a typical Arduino setup, so battery-powered embedded projects can start considering the Pi as an option. It helps, of course, that this is just $5! I just got my mini-HDMI adapter in the mail today, so I'll be running a few more tests to see if there are any other major differences between the Zero, the model 2 B, and the A+/B+ (I currently use the A+ for most small projects right now, and the 2 B when I need a little more CPU).

swiley 11y ago
The power consumption was the number 1 reason I couldn't use the PI in most of my projects so this is super exciting (the number 2 being cost).
- throwawydfje 11y ago
  if power and cost were 1 and 2 this is pretty good for you! Could I ask what the specific applications were? I'm very interested and wonder what other people have done. May have follow-up questions for you :)
geerlingguy 11y ago
I may also disable the HDMI interface as well, to see if it makes any real difference in power consumption. It's rumored to do so, but I haven't seen any proof that it helps. It can be disabled with the command: /opt/vc/bin/tvservice -o
- geerlingguy 11y ago
  Can't edit this post anymore, but I'll reply here: I just ran tests with HDMI disabled, and it looks like it does save ~30 mA. Running more tests, will leave a top-level comment with more notes soon.

pen2l 11y ago

> The Raspberry Pi Zero - quite a small Linux computer! Okay, I have a smalllll complaint. In popular modern-day English, R-pi is not really a 'computer'. Because you can't run a full-fledged operating system like Windows or Linux on it -- you have to run embedded version of those OSs (like Windows CE or whatever). I think I may not be totally and technically correct in my point here, but I think it's an important point to make or at least mention somewhere along the way anyway -- because, as it happens, I told someone that R-pi is basically a cheap computer... and this person was eventually miffed to find that he couldn't run the Windows applications he wanted to run on it, because those applications only could run on a x86 Windows install.

pjc50 11y ago
The solution to "cheap windows" is the various Bay Trail devices; so far the best offer I've seen is 7" tablet for £45 which comes with a year's subscription to Office 365 (worth >£50).
- hobbsy 11y ago
  do you have a link please?
  - pjc50 11y ago
    http://www.amazon.co.uk/gp/product/B00O636WJU http://www.amazon.co.uk/gp/product/B00O636WJU (price has gone up a bit)
- dogma1138 11y ago
  Tablets are usually locked tight. You can get the NUC board DE3815TYBE for under 100$ these days and it's completely open.
mikeash 11y ago
The problem is not people calling the RPi a "computer" (which it absolutely is), the problem is people who think "computer" means "Windows PC."
11y ago

throwawydfje 11y ago

Very interesting. Still far from solar-powered territory for outdoor projects, for example. Unless there were a way to wake the pi very easily. However, the raspberry pi includes no power management whatsoever; it's either off or on[1]. Why not? Does the chip not support it? --> Note that the article specifically calls out disabling USB, disabling ethernet (not relevant here), and disabling video output if not using it. I wonder if the author could try disabling HDMI to see if power is reduced.... This can be mitigated if there were a way to boot quickly on demand. See this writeup on sleepypi, an expansion-board that does just that:[2] So it should be possible to wake on demand by powering up and going through a boot cycle. Since the hardware is SO very fixed (not going to change short of ripping parts of the board off) I wonder why the boot time couldn't be further reduced...what really takes 10 seconds, during which the SD card could have read 200 MB or so? It's nearly enough time to wake from hibernation, were that supported. (SD card bus speed is limited to reading 20 MB/second or so). I'm sure it could be improved. This other write-up mentions using the previous generation for up to 24 hours for remote-location time-lapse photos [3] - also contains an interesting idea about underclocking. Not sure if this suggestion is relevant, possible, or works. [1] No sleep mode on pi: http://raspberrypi.stackexchange.com/questions/4773/raspberry-pi-sleep-mode-how-to-avoid http://raspberrypi.stackexchange.com/questions/4773/raspberr... [2] * Pi and SleepyPi: http://marktmarshall.com/2014/08/experimenting-with-raspberry-pi-power-management/ http://marktmarshall.com/2014/08/experimenting-with-raspberr... * An interesting FAQ on SleepyPi: http://spellfoundry.com/sleepy-pi/sleepy-pi-faq/ http://spellfoundry.com/sleepy-pi/sleepy-pi-faq/ [3] Powr saving on raspberry pi A in remote installations: http://babaawesam.com/2014/01/24/power-saving-tips-for-raspberry-pi/ http://babaawesam.com/2014/01/24/power-saving-tips-for-raspb...

bootload 11y ago
" I wonder if the author could try disabling HDMI to see if power is reduced...." from comments ~ http://www.midwesternmac.com/comment/3216#comment-3216 http://www.midwesternmac.com/comment/3216#comment-3216 in this article, "Controlling both the PWR and ACT LEDs on the Raspberry Pi 2" ~ http://www.midwesternmac.com/blogs/jeff-geerling/raspberry-pi-zero-power http://www.midwesternmac.com/blogs/jeff-geerling/raspberry-p...

mike-cardwell 11y ago

I'd really like to find a USB battery pack for one of these which can be used to make the device portable. I know there are loads, but they usually have one or more of the following problems: 1.) Can't power the PI at the same time as being charged 2.) PI consumes power faster than the battery can charge up 3.) Neither of the above two problems, but when you plug the battery into the mains it momentarily disrupts the PI causing it to reboot. Anyone know of a battery which will last with one of these for the best part of a day or more and which I can just plug into the mains when I'm near a socket to keep it topped up? [edit] FWIW, my plan (if I can sort the power) is to migrate my email and xmpp services from the fixed in place Intel NUC under my TV at home, to a Pi Zero in my backpack.

bapbap 11y ago
I am not a battery or electronics expert but my understanding is that it is not ideal to simultaneously charge and discharge a LiPO battery, so most don't support passthrough. I use a RAVPower Xtreme (26800mAh - though I'm not sure if I believe that rating) to power a dashcam and had similar requirements to you. However, I've implemented a DPDT relay and a 12V boost regulator to switch between the battery pack and car power (ACC), depending on the ignition status of the car. So when the car is on, the battery is being charged only and the dashcam is getting power from the car. When the car is off, the battery is only being used to power the dashcam. I've not tested it with a Pi but there is not an interruption in power long enough to disturb the dashcam (the relay spec is 8ms operate time). The battery pack is charged using a 2A 5V charger. I can't properly assess the charge status/history of the battery as it only has 4 LED's and I don't want to take it apart but so far my commute and other driving is long enough to keep it ticking over.
- disposeofme123 11y ago
  Its definitely possible, think about the circuitry in your phone and how the batteries work with that. As far as I'm aware, most modern phones can't turn on without a battery pack present in the phone, even when plugged in, which would suggest that the juice is actually coming from the phone battery at all times and not direct from the charger regardless of charging state.

deleted 11y ago

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geerlingguy 11y ago

Just did a bunch more testing, and I can get it to idle at ~40 mA if I disable HDMI (inside `/etc/rc.local`: `/usr/bin/tvservice -o`). With a WiFi dongle (so it can operate on the local network at least) and HDMI disabled, it hovers around 120 mA. Very, very nice!

deleted 11y ago
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- deleted 11y ago
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