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Solar phone charger

Bench build · Batteries and solar · Intermediate · about 15 minutes

Panel to USB with a buck converter. A 20 W panel makes 17–21 V; a buck module brings it down to a steady 5.1 V for a phone, trading voltage for current so a 1 A phone load only takes about 0.3 A from the panel.

Solar phone charger: the finished build running on the simulator's bench

Build it in the labGuided build, test sheet and fault finding, free in your browser.

Parts list

Test procedure

Each test has an expected value and a pass range, like a factory test sheet:

  1. Full sun: USB at 1 A
  2. Cloudy (400 W/m²): still regulated
  3. Panel current at 1 A out

How it works

What it does: Panel to USB with a buck converter.

Build it (guided or ready-made), then run its test procedure below. Every test has an expected value and a pass range, just like a factory test sheet.

Background

Camping, farms and typhoon kits: charge a phone straight from the sun.

More builds: batteries and solar