Trying to diagnose recent problems with my Pi which effectively rendered it unusable -- short freezes whenever I took an action in Kodi, temporary loss of network connection, all accompanied by red LED -- I found on this site that a bad power adapter can cause such symptoms. (Which is good, I thought maybe the Pi itself was dying!)

I have had this one for three years (running almost 24/7) so it could not have been the parameters of my power adapter per se. Switching to a tablet charging adapter, the problems went away, though. So apparently my power adapter got bad over time.

There seem to be parameters of adapters you can not check without expert knowledge and equipment; degrade of quality over time can only be harder to estimate.

Given the abundance of USB power adapters on the market these days, how do I pick one that

  1. is good enough to power a Pi reliably now, and
  2. is of sufficient quality to be reliable over years of constant operation?

In particular, one naive idea would be to oversize it (say, buy an adapter with >= 2A output) so that the Pi does not put anything near maximum stress on its power source.

Another idea would be to buy a "(multi-purpose) power adapter" instead of a "charger" (the bulk of the market) assuming that the formar would be built for providing continuous power supply.

  • Raspberry Pi power supplies are abundant. 2500mA at 5V. Some have switches, others use wall-warts that are directly connected. Yet others are a wall wart with a USB port. If you don't give it enough power you will get all sorts of strange errors. – SDsolar Jan 10 '17 at 2:31

A regulated power supply is your best answer for long term, continuous power delivery.

These power supplies use better components and deliver cleaner DC currents too. You can get really cheap ones but spending a bit more for better quality will prove to be worth it.

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Click here for a good source of various types.

Regulated (switched mode) power supplies VS Linear concept.

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  • Handles loads better, doesn't dip in voltage.
  • More efficient. If you only using a few watts then the socket uses only few watts and increases as more power is needed.
  • DC frequency is much cleaner, which is a big plus for WiFi
  • Is there a safe (i.e. does not involve any hacking you shouldn't do without the proper skillset) way to get their output on a USB plug? Are there some that ship with cables? – Raphael Jan 19 '16 at 9:51
  • Yea. Take a USB plug. Chop the end of you can't use. Put the red wire to +5v and black to 0v. That's all. But remember those USB wires CANT handle more than 1A constant load. – Piotr Kula Jan 19 '16 at 9:53

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