Saxat från en Victron artikel:
Victron SmartSolar and Blue Solar MPPT charge controllers allow you to bring in a higher voltage from your solar array. It is critical to design your solar array to ensure that your input voltage is 5V above your battery voltage - at a minimum. As you go up in voltage, your efficiencies will improve.
How does coming in with a higher voltage improve PV performance? Firstly, you can now wire panels in series and reduce connections on, for example, the roof of an RV or camper, which raises the voltage and bumps the current down. Secondly, coming in at a higher voltage means less cable line loss. We can also use smaller cables. Lastly, the time window in which you're able to charge batteries during the day—even in low-light conditions in the morning and late afternoon—is greatly expanded. You can start to see how little things add up very quickly to improve the overall efficiency of a system.
Watch the video below for a detailed explanation of why Victron MPPTs are designed to start at a higher voltage and the resulting efficiencies.
