Features Multi-state display, output switch control. Adjustable parameters for charging mode, stop charge voltage, low voltage recovery voltage, low voltage protection voltage. Overcharge, over-discharge, overload, short circuit, over-temperature and reverse polarity protection. Intelligent PWM charging method. Dual USB 5V output for charging mobile phones Ergonomically designed independent buttons. Specification: item type: solar charge controller Model: CMTD-A2420. Maximum charging current: 20 A. Maximum discharge current: 20 A. Maximum input voltage of solar panel: ≤40V System voltage: 12V/24V automatic (can be connected to 12.8V 4S LiFePO battery) Stop charging voltage: 14.7 V/29.4 V. Low voltage recovery voltage: 12.2V/24.4V Low voltage protection voltage: 10.5V/21.0V USB output voltage/current: 5V/500mA No-load loss: ≤10 mA. Temperature compensation: -3mV/cel1/℃. Working temperature: -20 ℃ ~ 60 ℃. Package list: 1 x solar charge controller. 1 x user manual (English language Package List 1 x Solar Charge Controller 1 x Manual