Answers (1)
It's not clear what you are trying to ask.
Solar cell output depends on the amount of sunlight, angle, dust, clouds, and a few other things. It is so unpredictable that you have to use a controller to stabilize the voltage enough to charge a battery. Then you run on battery power, which is a lot easier to use.
A 12 volt dry cell typically puts out a falling voltage with rising internal resistance. It is considered dead when it falls below 9 volts or so.
There is no way to combine the two.