The Studer Xtender can be used as a smart boost for a limited power or unreliable mains supply. In the above example the generator or grid is only capable of supplying 9 Amps AC at 230V. If the electrical consumers in the house (or boat) draw more than the maximum 9 Amps a brown out or problem with the generator will result. The additional short term 3 Amp demand (12 Required minus the 9 available) will be automatically provided by the battery bank.
The Xtender constantly monitors the incoming power from the grid or generator and as soon as it starts to equal and pass the 9 Amp limit it starts taking power from the batteries. When the peak demand has passed the Studer Xtender uses the AC input to recharge the batteries.