Solar Battery Charge Controller PCB

KiCad-based PCB design for an LT3652 solar battery charge controller / solar power regulator. This project includes the schematic, PCB layout, routed board design, connector labeling, and 3D board renders.

The circuit is designed to take a solar input and manage battery charging using the LT3652 charger IC, with battery terminals, solar input options, and a status/control header for CHARGE, FAULT, GND, and SET.

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📌 Project Overview

This PCB is a compact solar-powered battery charging controller designed for embedded, portable, and low-power solar applications.

Main functions:

• Solar input regulation
• Battery charging control
• Battery terminal connection
• Charge and fault status output
• Adjustable charge/control setting
• Screw terminal and barrel jack style input support
• KiCad schematic, PCB layout, and 3D visualization

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🧩 Main Components

Reference	Component	Description
U1	LT3652	Solar battery charger IC
BT1	Battery holder / battery cell	Battery connection
J1	Solar input screw terminal	VIN+ and GND input
J2	Battery terminal	V_BAT+ and V_BAT-
J3	Solar input barrel jack	Alternative solar input
J4	Status/control header	CHARGE, FAULT, GND, SET
L1	Inductor	Charging circuit inductor
D1, D2	Diodes	Reverse/current path protection
RV1	Potentiometer	Adjustable control setting
C1-C6	Capacitors	Filtering and stability
R1-R7	Resistors	Feedback, status, and control network

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🔌 Connector Pinout

J1 — Solar Input Terminal

Pin	Signal	Description
1	VIN+ / SOLAR_IN	Positive solar input
2	GND	Solar negative / ground

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J2 — Battery Terminal

Pin	Signal	Description
1	V_BAT+	Battery positive
2	V_BAT- / GND	Battery negative / ground

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J3 — Solar Input Barrel Jack

Pin	Signal	Description
1	SOLAR_IN	Solar input positive
2	GND	Ground
3	Switch pin	Barrel jack switch contact, depending on jack footprint

Note: J1 and J3 are connected to the same solar input net, so they should not be used with two different power sources at the same time.

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J4 — Status & Control Header

Pin	Signal	Description
1	CHARGE	Charge status output
2	FAULT	Fault status output
3	GND	Ground
4	SET	Control / set input

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🖼️ PCB Preview

Schematic

PCB Layout

3D View

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⚠️ Safety Notice

This PCB handles battery charging. Incorrect wiring, wrong battery chemistry, wrong charge settings, or poor thermal design can damage components or batteries.

Use proper lab testing procedures:

• Use a current-limited power supply during first power-up
• Do not leave the circuit unattended during initial charging tests
• Confirm the battery type and charging requirements
• Follow the LT3652 datasheet recommendations
• Use proper fuse/protection if used in a final product

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👤 Author

Designed by Fernando S.M.H.G.

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