When used with a solar panel (the EcoFlow 220W one in this case) the unit can actually lose charge. Let me clarify:
Obviously, when switched off, no charge is lost. But if a solar panel is connected it seems that as soon as there is enough daylight for the solar panel to output something, this turns the unit on. At this point, the unit can be using more than the solar panel is providing. So if it is a dull, cloudy day, it seems that the solar panel keeps the unit on while not providing enough power to cover the residual needs of the unit.
Hence, if left with the solar panel connected over several cloudy days, while the unit will switch off each night, the solar panel output turns it on come daylight and, overall, the unit will lose power.
Obviously, when switched off, no charge is lost. But if a solar panel is connected it seems that as soon as there is enough daylight for the solar panel to output something, this turns the unit on. At this point, the unit can be using more than the solar panel is providing. So if it is a dull, cloudy day, it seems that the solar panel keeps the unit on while not providing enough power to cover the residual needs of the unit.
Hence, if left with the solar panel connected over several cloudy days, while the unit will switch off each night, the solar panel output turns it on come daylight and, overall, the unit will lose power.