Review on ECO-Worthy 30A Solar Charger Controller | Solar Panel Battery Intelligent Regulator with Dual USB Port | Auto 12/24V PWM Positive Ground by Nick Winnett

This product is advertised as negative ground when it is not. Negative grounding means that the negative line of the solar panel, the negative line of the battery and the negative line are internally connected, and you can securely fix the negative charge to the frame of your car or computer. All positive poles of this controller are grounded, as with most inexpensive solar controllers. It is very difficult to work with positive ground because all modern vans, cars, trucks, power packs, etc. have negative ground. In practice, this makes it impossible to connect a computer to measure the voltage on the solar panel, the battery will not appear due to a minus. NEVER connect the negative terminal of this device to the chassis of a car or computer.