I am using a raspberry pi for a school project and I am looking for a method to switch between two different power supplies. We have a solar panel that is connected to a charge regulator and the charge regulator is connected to a battery. In order to make it as efficient as possible, my group wanted to alternate between a 5V output from the charge regulator and a 5V output from a rechargeable battery. Essentially, I want the charge regulator to be the primary source of power so that it will supply the 5V all the while recharging the battery. When the solar panels aren't providing sufficient power, I want the battery to be the main power supply. Therefore, I am looking for a circuit that can monitor when the 5V from the charge regulator begins to fall and then switches to the battery.
I found this http://www.linear.com/product/LTC4353 and was wondering if this would work with what I'm trying to do.