Compact PWM Solar Charge Controller, Pen Form Factor Overview A compact solar charge controller designed for small 12 V or 24 V systems with automatic voltage recognition. The unit uses PWM charging to regulate battery charge, includes a USB output for device charging, and features builtin protections to safeguard system components. Key benefits Automatic 12 V and 24 V recognition simplifies installation and prevents incorrect wiring. PWM charging supports reliable battery maintenance and extends usable battery life in small systems. Builtin protections for short circuit, open circuit, reverse connection, and overload help protect panels, battery, and loads. USB output provides convenient 5 V 2 A power for charging phones or small devices without adding an external adapter. ABS housing offers lightweight durability for indoor or sheltered outdoor installations. Compact penstyle form factor and included screw fittings make mounting simple and space efficient. Specifications Item type: Solar controller (PWM) Material: ABS plastic housing Nominal voltage: 12 V / 24 V automatic recognition Maximum charging current: 10 A or 20 A (model dependent) USB output: 5 V 2 A Charging method: PWM No load loss: not specified Package contents 1 solar controller unit (pen form) 8 screw fittings for mounting 1 user manual; English language not Installation and operation notes The controller generates heat during normal operation. Install on a flat, well ventilated surface to allow heat dissipation. Confirm system voltage before connection. The controller automatically recognizes 12 V and 24 V systems but correct wiring is essential. Use the supplied screw fittings to secure the unit and reduce vibration in mobile applications. Typical applications Small off grid solar kits for cabins, sheds, or garden lighting using 12 V or 24 V battery banks. Auxiliary battery management for RVs, campers, and boats where controlled charging and a USB power outlet are useful. Portable or temporary solar setups for camping, fieldwork, or emergency power that require a compact controller and device charging capability. What this product solves This controller provides a simple, compact solution for managing solar charging in small systems. It prevents common charging faults through builtin protections, supplies a convenient USB output for device charging, and supports both 12 V and 24 V batteries without manual switching. The included mounting hardware and small footprint suit installations where space is limited. Compatibility and performance Designed for lead acid and similar 12 V or 24 V battery systems when used with PWM charging profiles. Select the 10 A or 20 A model according to panel and battery capacity to ensure safe continuous current handling. Safety reminder Avoid installing near flammable materials. Ensure adequate ventilation and do not enclose the controller in a sealed compartment during operation.