Battery as input for Grid Tie inverter, possible?

Me and friends are trying to do a project wherein we have to setup a solar powered system which is connected to a grid-tie inverter. However, what I want is, the solar panels will charge only the batteries and will not directly flow to the inverter. My problem is, most Solar power companies tell us that using... show more Me and friends are trying to do a project wherein we have to setup a solar powered system which is connected to a grid-tie inverter. However, what I want is, the solar panels will charge only the batteries and will not directly flow to the inverter. My problem is, most Solar power companies tell us that using Battery as source into the Grid tie inverter is well, "risky". I wonder why they say so since the voltage and current charge will not overcharge the inverter since it has a charge controller. Any view about this? Thank you!
Update: Ah thanks, however (sorry for not mentioning earlier), we are not using the battery while it is charging. We will allot a time frame for charging it and we will start using it once it is completely charged. Is it still safe?
6 answers 6