Intermediate

Solar Phone Charger

Create a small protected solar USB charger using ready-made charging and boost modules.

Safety first, always.

ElectroLab AI teaches theory, low-voltage electronics, and planning concepts. Mains voltage, switchboards, fixed wiring, high-current systems, and legal electrical work must only be performed by licensed electricians where required.

Open Safety Center

Guided visual build

See it, place it, test it, then debug it.

Visual schematic

Solar charger flow

Panel energy passes through charge control before the battery and protected 5 V output.

Low-voltage model

TP1: panel volts

TP2: battery volts

TP3: USB output

Power low-voltage projects from batteries or current-limited supplies first. Stop if a part heats, smells, sparks, or behaves unexpectedly.

Interactive build mode

Solar Phone Charger step-by-step

Move one build action at a time. Treat each step as a checkpoint before adding the next connection.

Progress

1 / 5

Current action

Choose a solar panel that matches the charger module input range.

Wiring focus

Stage 1 of 5

solar panel

charge controller

battery pack

USB boost

load test

Identify the part and orientation before placing the next wire.

Use protected battery packs and approved charging modules. Lithium batteries can burn if shorted, overcharged, punctured, or wired incorrectly.

Project test bench

Pre-flight, first power, and fault response.

Treat this like the bench checklist beside the project. Tick what is proven, then use the symptom picker if the circuit does not behave.

Readiness

Do not power this yet

Pre-flight checks

Power source voltage matches the project parts.Positive and negative rails are identified and not swapped.Polarized parts have been checked before power-up.A current limit, fuse, resistor, or safe supply protects the first test.Meter is set to the correct mode before touching probes to the circuit.Battery chemistry matches the charger module.Battery output is fused or current limited.Panel polarity is confirmed before connecting the charger.

Before power

Measure supply polarity and expected voltage at the rails.

During first power

Use current limiting and watch for heat, dimming, or voltage collapse.

After a fault

Power off, isolate one section, then measure from source toward load.

Build target

Learn solar input, battery protection, boost conversion, and load limits.

Build steps

1.Choose a solar panel that matches the charger module input range.

2.Connect the panel to a solar charge controller module.

3.Connect the battery pack with correct polarity and protection.

4.Feed the protected battery output into a USB boost converter.

5.Test charging current in sun before plugging in a phone.

What you are learning

1.Solar panels behave like variable current sources depending on light and load.

2.Battery charging requires chemistry-specific voltage and current control.

3.A boost converter raises battery voltage to 5 V USB output.

Bench tests

1.Measure panel open-circuit voltage in sun.

2.Measure USB output voltage with no phone connected.

3.Test with a dummy USB load before charging a device.

Fault finding

1.No USB output: check battery voltage and boost module enable pin.

2.Battery not charging: check panel polarity and sunlight level.

3.Module heats up: load current may be too high.

Upgrades

1.Add a fuse and power switch.

2.Add a voltmeter display.

3.Use a larger panel and battery with a rated enclosure.

Project safety

Use protected battery packs and approved charging modules. Lithium batteries can burn if shorted, overcharged, punctured, or wired incorrectly.