We usually measure or convert the watts into amps of solar panels to figure out how much current (amps) is being stored in the battery. Or we measure the amperage of the solar panel output to select the wire sizefrom solar panels to.
The 150Wh version provides approximately 40–50% of the storage capacity of a standard car battery, while the larger 300Wh version offers nearly double that capacity, ideal for extended usage or powering larger devices.