http://www.mybmwi3.com/forum/viewtopic. ... 4&start=30
It is all there, you can read out SOC and kWh capacity in a hidden menu of the board computer. Plus battery temperature and other data. Was discovered and reported about in Facebook by one Chad Hogan. Use at own risk.
On the small display there is a button for trip reset on the left side.
Press and hold this for 10-12 seconds - you are in.
Press through until option 4 "Lock", then press and hold for about 4 seconds until "Number"
Your individual number you get by adding up the last 5 digits of your VIN. My VIN is 71776, so my number is 28.
Press through to your number, then press and hold again - you are in the menu.
In 13 you find SOC, absolute and momentary battery capacity, REx fuel capacity and others. In 14 you find battery temperature und others. And so forth.
Unfortunately you have to go through this every time you start the car.
Frank