Abstract: A hybrid battery-charging device with input terminals for connecting a current source, first and second battery connections for connecting a lead-acid battery and a high-cycle chemical battery. A two-way DC/DC converter with first and second sets of terminals is connected with the second and first battery connections. A charge and discharge control system includes a controller unit, a control output for controlling the two-way DC/DC converter, and sensing inputs for sensing a charge state, an internal resistance of the lead-acid-battery and state of charge of the high-cycle chemical battery. The charge and discharge control system controls the two-way DC/DC converter such that the lead-acid battery is charged if its charge start is below a pre-determined threshold and that the high-cycle chemical battery is charged if its charge state is below a pre-determined threshold and if the state of charge of the lead-acid battery is above a pre-determined threshold.

Abstract: A hybrid battery-charging device with input terminals for connecting a current source, first battery connections for connecting a lead-acid battery and second battery connections for connecting a high-cycle chemical battery. A two-way DC/DC converter with first and second sets of terminals is connected with the second battery connections, and with the first battery connections. A charge and discharge control system of the charging device is operative to detect when an internal resistance of the lead-acid battery exceeds a predetermined resistance threshold, and to control the DC/DC converter, in response to the internal resistance of the lead-acid battery exceeding the predetermined resistance threshold, such that, in a discharge mode, the lead-acid battery and the high-cycle chemical battery are discharged in parallel during a parallel discharge phase.

Abstract: A battery charging apparatus. The apparatus includes two or more hybrid battery charging devices. Each hybrid battery charging device includes input terminals for connecting a photovoltaic panel, first battery connections for connecting a lead-acid battery, second battery connections for connecting a high-cycle chemical battery, a two-way DC/DC converter, a charge and discharge control system, which is connected to the two-way DC/DC converter, and output terminals for connecting a load.