This tutorial enables you to power your Raspberry PI II / B+ / ZERO/ 3 from any power sources that supplies voltage between 6.5V up to 20V and current >1A. For this how to, I used as power source the 19V wall power adapter from one old BENQ notebook. This hack is useful, also, in configuration where gel-Lead(Pb) rechargeable batteries are used as power supply. Time needed: between 15 to 30 minutes. Skills required: soldering.

Gathering all parts and tools together

Parts:

• 1pcs. x g-SPS 5V version switching power supply
• 1pcs. x 2.1mm/2.5mm barrel power jack (choose one that fits with your wall adapter) or see the "Barrel jack alternative" and g-SPS reference later
• 1pcs. x 3 pins standard 0.1"/2.54mm row-header 90 degrees or straight + connecting wires x2
• optional 1000uF/6.3V electrolytic capacitor, low ESR (optional, useful in case of high current consumption pulses)

References:

• about g-SPS 5V version [PN. gSPS102#5V(LiPOL)]
• Raspberry PI 2 / Raspberry PI B+ / Raspberry PI ZERO extension pin out

Tools:

• soldering iron
• small pliers / clip

Soldering the connectors

Remove the central pin from the pin-header using the pliers or the clip. Solder the pin-header (see the two pictures above). Solder the barrel connector (optional, see "Barrel jack alternative" later). Check for short-circuits!

Wire the boards together

Connect the wires as shown in the above picture. Double check the polarity! You are ready. Enjoy! HINTS:

• Barrel jack alternative - you can use 2pin standard 0.1"(2.54 mm) soldered to the +Vext and GND pads, as input power source connector. See details on g-SPS references.
• Increase the stability for bigger current loads - you may use one 1000uF/6.3V lowESR electrolytic capacitor. Bend the capacitor terminals to 90degree, insert it(from the top side)) to the "+" and "GND" [placed just above the "+" hole marking] vias/holes and solder it. (reference: "g-SPS 5V version, back side" picture above)

  TUTORIAL  PROVIDED WITHOUT ANY WARRANTY. USE IT AT YOUR OWN RISK. Originally published by Dragos Iosub & itbrainpower team.