I just attached a Mean Well LRS-100-5 5V 18A powersupply to my Rpi. And I still get the bleeping annoying undervoltage message.
I don't care about undervoltage, if it bleeps up my installation then I'll re-install.
I just don't care anymore, no matter what I do there's apparently undervoltage to my Pi. I just want to use it without restrictions.
And please don't give me any suggestions on how to solve the undervoltage issue. If an 18A power supply can't do it then nothing can. I want a back door to make this work and to be able and make my own decisions whether undervoltage is an issue or not.
Ok, found the answer. I have done some extensive googling on this before asking the question, but never found the answer until now.
Disclamer: This might damage your Pi and/or sd card so be careful. I have used my pi:s for over a year with this pesky message/warning making my life hard to live so I felt confident enough to disable it. But it might not work for you.
I edited the file " /boot/config.txt" and added these lines to the bottom of the file:
#Disable under voltage warnings
avoid_warnings=1
avoid_warnings=2
Use it at your own peril.
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The warning is about undervoltage, 18A is all very well and good but if it's less than 5V... then you have your issue.
Besides, the Meanwell power supply you have has an adjustable voltage from 4.5 - 5.5v:
It is probably as simple as adjusting this to increase the voltage slightly...
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Just get a good cable (as short as possible) between your Pi and the adapter (at least 5v 2.5 amp) and you don't have under power problems. I have several pie's and with the same kind of cable they all have the same under power problems. With a good cable they don't have problems. If your power source extends the maximum needs (Pi3=5V /2.5A=12.5watt) and still having problems, it for sure is the cable. Best cable's are the cable's that are used for fast charging phone's, pads etc. Cable's used for just USB data only can handle the normal USB output of 5V/0.5A (ie 2.5 watts).
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It's my understanding that the Pi's use 5.1v from their power supplies. I always use their supplies and don't have that problem. (I am running 10 Pi's on my network.)
Just like putting a piece of tape over a "CHECK ENGINE" light, you haven't changed anything. There's strong correlation between print failures and undervoltage- not undervoltage warnings. Why? Because even without the warning, your Pi is still throttling the CPU down.
As Charlie_Powell described: Check the Voltage wih a Voltmeter while your RasPi beeing under load. If the Voltage (measuring between Pins: Nr 2 or 4 [+5V] and Pin 6 [GND] ) - is under 4.95V, then you definitively have a Voltage-problem - and don't take this easy! - which is solved only with a higher Voltage-Input near the USB-Connector or the mentionned 5V Input-Pins. Voltages above (upto about 5,5V) are not really problematic, due to the internal Power-5.0V-Z-Diode of the majority of all Pi's on board, which truncates all incoming Over-Voltages, either coming from USB or directly from one of the two pins "2" or "4"... but take care about, if incoming Voltage is under 4.9V - as tedder42 said!
Hi,
I had the same problem and I adjust the power supply to 5,4v and no problem since one year.
Have a good day.
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I would grab a multimeter and see what comes out of that power supply UNDER LOAD and adjust the trimmer (it has one) so that the voltage reaches 5.1V. Don't go overboard as you'll overheat and that will be another issue. Keep it around 5.1V. My guess would be that the trimmer is set on the low side and under load that drops even further and your Pi is complaining rightfully. But I might be wrong... check and get back to us with what you found. That's the only way we'll all learn. But please, don't disable the safeties because it's annoying.
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