Remote stations are located away from populated areas; as a consequence they need complementary power systems to avoid the lack of 220 V power line, such as photovoltaic panels coupled to 12 V batteries. However, the batteries suffer the repeated charge cycles that can reduce their lifetime. It is also difficult to test the state of the batteries during the day, because they are simultaneously charged by photovoltaic solar panels; if the batteries have problems, the stations may stop working during the night.