You can use this Solar charger to charge 12 volt Lead Acid or Tubular battery. It is voltage controlled and charge the battery when the output from Solar panel exceeds 15 volts in bright sunlight. The open circuit voltage of a 12 volt solar panel is around 20 volts in full light and the 12 volt battery requires around 14-15 volts for charging. The circuit also prevents the discharge of battery into the solar panel when the sunlight is low.
12 Volt 10 Watts solar panel gives around 1.2 ampere current in bright light. But it is not constant since the intensity of light vary considerably depending on the climatic conditions. When there is sufficient output from the panel, T1 conducts to charge the battery.