Abstract: The present invention relates to solar battery technological, and embodiments of the present invention provide a method, device and system for supplying power with light voltage battery. In the embodiments provided by the present invention, through a parameter scale value corresponding to electric energy generated by a tested object under current illumination condition, by adaptively adjusting a connection manner among multiple light voltage battery units in the light voltage battery combination unit, it is applicable to obtain needed electric energy from the light voltage battery combination unit. By this method, when light voltage battery is applied and illumination condition keeps changing, it can avoid the light voltage battery combination unit from outputting over-voltage or under-voltage electric energy.