Is the power from solar panel redirected to load when battery is full?
Lets consider that I have a 100 Watt solar panel, The MPPT charge controller is connected to 12V battery and the load is a 12V bulb. When the battery is fully charged does the charge controller transfers power directly to the load instead of battery?


This is a meaningless question. Let's assume for a second the answer is "no". That would mean that the battery would discharge due to the load. That would mean the battery wouldn't be fully charged anymore. Which would mean the answer wouldn't be "no" anymore.

So you're asking what happens in a hypothetical split second in which the battery is fully charged.

In any event, most actual charge controllers just connect the battery and the load directly to each other whenever they want to supply power to the load. They then manage the connection between the solar panel and the battery+load to supply as much power to the load and battery as they possibly can, backing off if the battery voltage gets too high.

They don't care (and often don't know) how much of that power is going to the battery and how much is going to the load. There job is just to:


Get as much power to the load and battery as possible, except
Don't let the battery overcharge -- back off the power if that happens, and
Don't let the battery overdischarge -- shut off the load if that happens.