Abstract: A hybrid battery charging device includes: input terminals for connecting a photovoltaic panel or other current sources; first battery connections for connecting a lead-acid battery; second battery for connecting a high-cycle chemical battery; a two-way DC/DC converter having a first set of terminals connected with the second battery connections, and a second set of terminals connected with the first battery connections, an input of the second set of terminals being derived from the input terminals; a charge-and-discharge control system which is connected to the DC/DC converter via respective control lines; and output terminals for connecting a load, an input to the output terminals being derived from the first battery connections.