1. The PRO has 2 voltage input sources, the standard 16V input (which most batteries in the market use) and the 48V input (plug-in AC source).
2. The PRO uses 300W of power, so each battery would output a maximum of 120W, and 2 batteries would
equal 240W. 240W is 80% of 300W, hence the limit.
3. Why can 2 batteries only output 120W each while the power supply can supply the
whole 300W? It's because the current max for the connectors are rated at 10A, so at 12V and 10A for the battery, the output is maxed out at 120W. While the power supply operates at 48V, which only needs around 6.25A to reach 300W.