charging bypass circuit

Hi everyone, I have 10 solar lights ,I want to use the modules to charge the batteries then bypass the charging circuit go to an electrolysis set up. When the solar modules quit charging I want the batteries to go to the electrolysis set up and when the sun comes up the process will cycle again. I would like to use the charging circuits that came with the modules, abd the batteries as well but the lights will be removed. What will i need to bypass charging circuit and restart the cycle