@Tim I'm not sure the installers can initiate the calibration cycle. At least, mine (2weeks ago) said that they had to inform GE and GE will do what is necessary. My installers only connected it, checked that it is on the system... and left.
Anyway, it took something like 4 or 5hrs for the battery to start calibration from the time of connection. The process takes some time, so technically my battery was ready on the morning of the next day. And it still took another couple of days to get the correct "8.2kWh" displayed on the portal. Sorry, forgot to mention that my battery was initially recognised as 5.6 (or thereabouts)kWh.
So, @lightningad you need to have a look at your portal, click on "My Inverter" link and look for where it says "Battery Capacity". What does it say there?