Battery Storage - filling amounts and time of day

I am on a student team of graduate researchers. We are looking at rooftop PV with battery storage in Georgia.  Our first simulation is with a very small installation that yields very little generation, but this is the class default we have to start from. We got weird output for how the battery is filling and want to check our assumptions. 

Here is an excerpt from our paper, our model file is attached. I'm curious why the battery is filling at all.
In our revision, we will re-size the panel design, so that it hopefully utilizes the battery more. 

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The SAM hourly data tablesshow that the electricity to load from PV starts at 7am and continues through
6pm. In addition, electricity to load from the battery is variable from 4pm to
10pm, and averages less than 0.1 kW per hour. The SAM reports demonstrate that thebattery is modeled to come online at 50% charge, and after 8pm on January 1st,
it remains at 15% charge for the rest of the year. We assume that the battery
is drawing a very small current to prevent any loss or deterioration over the
course of 24 hours, but it is not acting like a true storage system. Therefore,
the battery is unable to meet its full potential because the PV system is not
producing enough energy to fully utilize the battery.[url=#_msocom_1][BMA1][/url]  [url=#_msoanchor_1][BMA1][/url]Did you find this in a SAM reference manual? Can you provide a citationand page number? It would be good to double check this, because it would seem
to be so counterproductive. 

Hi Alyson,
I'd like an answer to your question too.  I did some modelling with SAM today, and with just batteries and almost zero PV, I generate a lot of energy.  This seems like a bug, but maybe it is is my input data.  I submitted it today, and maybe it will be approved with an answer tomorrow.  I think your question may be related to mine.
Rob