Electrical – Can a DC power source, such as batteries, cause over-voltage or current spikes

batteriescurrentpowerpower supplyvoltage

I'm looking to build a DIY battery power-supply for my Raspberry-Pi3. My electronics engineering skills are intermediate/novice, and as I had began research on the project, I ran across the following excerpt from a web-article about powering the Raspberry-Pi directly via it's GPIO pins:

"A more technical (and of course dangerous) way to power the Pi is directly via the GPIO. It should be noted that, unlike the Micro-USB port, there is no regulation or fuse protection on the GPIO to protect from over-voltage or current spikes. If an incorrect voltage is applied, or a current spike occurs on the line you can permanently damage your Raspberry Pi. At best, you’ll “burn out” some or all of the GPIO pins, at worst you can fry your Pi! So be careful."-modmypi.com

Can battery power source cause power-spikes or over-voltage? Should I be considering regulation?

Best Answer

Discard that website. The infomation they give is ill-advised to wrong.

You cannot power the Raspberry Pi through the GPIO pins. You can power it through the power pins of the 40-pin header. The only difference between doing that and using the Micro-USB power input is a fuse in the +5V line. As the +5V line is routed directly to the other USB ports, you can burn out the copper traces on the Raspberry Pi board if you use a powerful power supply at the 40-pin header and produce a short circuit on the USB ports.

The other traces on the board are protected by the fact they are behind voltage regulators with built-in current limiting.

"Burning out" GPIO pins happens when clueless people connect too high loads to them, or connecting them with +5V or even higher, instead of at maximum +3.3V. This isn't related to the +5V power supply.