Stackable Inverter allows them to act as a single system. They will work together to charge batteries and provide power to loads. When you need more power one day. Stack one more SI inverter to have more power. Solar charge controller: option and communicated with PM Premium series. In a system, when it is working, the master inverter must be powered on, and the working quantities of the other slave inverters depend on the usage of the load. So it’s very convenient to use and can maximize reduce the power loss. A top Stackable Inverte brand in Taiwan, over 15 years devoted to providing quality power inverter with a reasonable prices for consumers.