pi3b+ needs a beefier power supply than the pi3b

[386sx]

The Stontronics supply was changed from 2A to2A5 about the time the Pi3B was launched, IIRC. 2A was enough for previous models but 2A5 is recommended for the Pi3B and Pi3B+ to allow the full 1A2 for USB devices.

FWIW, having finally acquired the newer version, and had the time to update my webpages, here are my (updated) measurements of the (static) current loading of both versions of the (Stontronics) PSU:
http://www.cpmspectrepi.uk/raspberry_pi ... _Models.29
Trev.

Interesting, thank.

[marcosbong]

The Stontronics supply was changed from 2A to2A5 about the time the Pi3B was launched, IIRC. 2A was enough for previous models but 2A5 is recommended for the Pi3B and Pi3B+ to allow the full 1A2 for USB devices.

FWIW, having finally acquired the newer version, and had the time to update my webpages, here are my (updated) measurements of the (static) current loading of both versions of the (Stontronics) PSU:
http://www.cpmspectrepi.uk/raspberry_pi ... _Models.29
Trev.

Interesting, thank.

Usefull graphics, thanks

[jahboater]

Worth noting the Official PS is actually 5.1v at the wall end, and uses thick copper wires, so by the time the power gets to the Pi itself, its dropped only slightly to 5v.

I think its better than that. The cable is "fixed" so the specified voltage is measured at the end of the cable, at the Pi end.
The heavy 18AWG cable helps ensure that the voltage at the Pi end doesn't vary much with a changing load.

I believe that is why it is only 5.1V and not 5.2V because that would have caused problems with older Pi models that didn't have the fancy voltage regulator.

[W. H. Heydt]

I believe that is why it is only 5.1V and not 5.2V because that would have caused problems with older Pi models that didn't have the fancy voltage regulator.

Hard to say... 5.2v is still within the USB spec. More likely it's to keep the manufacturing tolerances to within the specification upper bound of 5.25v.

[KoolDud3]

This was mentioned in the launch video, but struggling with current 2A random adapters which have always worked for me with pis in the past.

Official raspberry pi adapter is a lot of dollars shipped to Canada. On the lookout for something local... any ideas? 2.5A seems rarer than 2A.

I have the official power by raspberry pi. It runs on 5V 2A and works fine.

Oh, and i have an rpi 3 B+

[Imperf3kt]

To those recommending the official PSU, I'll just leave this quote as a friendly reminder of what power supply we are discussing.

Hello.
Anybody here knows why I have an official Raspberry pi power supply made by Stontronics, but rated 2A ?

[HawaiianPi]

I have the official power by raspberry pi. It runs on 5V 2A and works fine.

Oh, and i have an rpi 3 B+

As already stated, the OLDER official power supply was rated for 5V at up to 2A. The newer one is 2.5A, and the 2.5A rating includes 1.2A for the USB port power.

Your Pi 3B+ runs fine on 2A because you don't have any power hungry accessories attached (but you only have 700mA available for those, which is 42% less than with the newer PSU).

[HawaiianPi]

Worth noting the Official PS is actually 5.1v at the wall end, and uses thick copper wires, so by the time the power gets to the Pi itself, its dropped only slightly to 5v.

I thought that power supplies with built-in power cords were rated at the output plug, not the wall-wart?

My official PSU outputs a little over 5.1V when measured on my running Pi 3B+ computer.

[widgetphreak]

To complicate matters further, Frys Electronics in the US is selling Power Supplies for the RPi made by a company called Rhino... the box specifically says "Supports Raspberry Pi 2,3, 3B,& 3B+"
Don't believe the box... I bought a 3B+ from Frys and that adapter to go with it... got it home, downloaded fresh image... Powered it up... yellow lightningbolt the entire time. Installed Kodi... menu browsing slow as heck... try to queue a playlist of videos... significantly longer pause between videos. Install emulation station... load up Tony Hawk on PS-ONE... game freezes for a solid second every 19 seconds or so.

I've been running the thing under-clocked for the last month just to get by... and I've finally decided to just offer it up for trade on Facebook Marketplace locally for a 3B [nonplus]. I can power my other 3B from a USB Battery Power Brick no problem... the 3B+ won't even load the OS while being powered by a USB Battery. I hope Element 14 is not planning to completely discontinue the 3B [nonplus] because honestly it is NOT worth all these Power Supply hassles... and losing the ability to Power it from an off-the-shelf USB Battery just to gain Gigabit Ethernet and a couple extra Mhz.

[ejolson]

To complicate matters further, Frys Electronics in the US is selling Power Supplies for the RPi made by a company called Rhino... the box specifically says "Supports Raspberry Pi 2,3, 3B,& 3B+"
Don't believe the box... I bought a 3B+ from Frys and that adapter to go with it... got it home, downloaded fresh image... Powered it up... yellow lightningbolt the entire time. Installed Kodi... menu browsing slow as heck... try to queue a playlist of videos... significantly longer pause between videos. Install emulation station... load up Tony Hawk on PS-ONE... game freezes for a solid second every 19 seconds or so.

I've been running the thing under-clocked for the last month just to get by... and I've finally decided to just offer it up for trade on Facebook Marketplace locally for a 3B [nonplus]. I can power my other 3B from a USB Battery Power Brick no problem... the 3B+ won't even load the OS while being powered by a USB Battery. I hope Element 14 is not planning to completely discontinue the 3B [nonplus] because honestly it is NOT worth all these Power Supply hassles... and losing the ability to Power it from an off-the-shelf USB Battery just to gain Gigabit Ethernet and a couple extra Mhz.

Sorry about your Rhino problems. Age old wisdom I learned in school is that the way to stop a rhino from charging is to take away its credit card. Unfortunately, it was not discussed in school how to make a Rhino charge, which seems closer to what you need.

I think it is possible to disable the gigabit Ethernet and down clock the Pi 3B+ to reach power-consumption levels and functionality similar to the 3B. That way you can retain the other benefits of the 3B+ which include better heat dissipation and regulation of the internal 3V supply used to power the SOC.

[jamesh]

To complicate matters further, Frys Electronics in the US is selling Power Supplies for the RPi made by a company called Rhino... the box specifically says "Supports Raspberry Pi 2,3, 3B,& 3B+"
Don't believe the box... I bought a 3B+ from Frys and that adapter to go with it... got it home, downloaded fresh image... Powered it up... yellow lightningbolt the entire time. Installed Kodi... menu browsing slow as heck... try to queue a playlist of videos... significantly longer pause between videos. Install emulation station... load up Tony Hawk on PS-ONE... game freezes for a solid second every 19 seconds or so.

I've been running the thing under-clocked for the last month just to get by... and I've finally decided to just offer it up for trade on Facebook Marketplace locally for a 3B [nonplus]. I can power my other 3B from a USB Battery Power Brick no problem... the 3B+ won't even load the OS while being powered by a USB Battery. I hope Element 14 is not planning to completely discontinue the 3B [nonplus] because honestly it is NOT worth all these Power Supply hassles... and losing the ability to Power it from an off-the-shelf USB Battery just to gain Gigabit Ethernet and a couple extra Mhz.

Sorry about your Rhino problems. Age old wisdom I learned in school is that the way to stop a rhino from charging is to take away its credit card. Unfortunately, it was not discussed in school how to make a Rhino charge, which seems closer to what you need.

I think it is possible to disable the gigabit Ethernet and down clock the Pi 3B+ to reach power-consumption levels and functionality similar to the 3B. That way you can retain the other benefits of the 3B+ which include better heat dissipation and regulation of the internal 3V supply used to power the SOC.

Or just get a decent power supply.

[Andyroo]

...
Or just get a decent power supply.

Way too easy - pass me the soldering iron - I'm going in...

Sorry - its been a long day and I feel as bad as my jokes.

[hdtodd]

Yup, the problem is many micro-USB cables have unknown specs.

Some will have markings on them similar to this:
USB_wire_gauge.jpg
The outlined number is the power wire gauge (24 AWG in this case).

I have micro-USB cables with 23, 21, 20 and even 19 AWG power wires, which all work great with my Pi3B computers. I generally use cables with a length of 1 meter or less (the Pi3B on my desk is powered by a 1.5 ft cable with 23 AWG OFC power wires).

Thanks, particularly, for HawaiianPi's observations two years ago. They pointed me to the solution of an annoying and persistent problem.

I'm running a Pi-3B+ TTN gateway with RAK2245 LoRa concentrator and no other devices attached (no HDMI, no external drive, no USB devices). It would run a couple of days then halt. No error messages in logs to tell me what happened. I did see "low-voltage"/"voltage-restored" messages at boot time pretty routinely. I thought it might be a power-supply issue, so I tried a couple of (nominally, at least) 2.5A supplies and continued to have the problem.

I finally decided to try to nail the problem down and found this thread. I was using what turned out to be a 1-m 24 gauge USB cable for power. Didn't have anything with lower gauge, but I did have a 6" 24 gauge cable. Plugged it in, and no more low-voltage warnings. Still to be seen if it runs for days, weeks, months without crashing, but switching cables seems to have solved at least one major problem.

A lesson I first learned over 50 years ago that continues to come back and bite me if I forget it: in case of problems, always check your cables.

Thanks for the help, all.

David