That battery was manufactured 09/01/2016. Use the eight digits after the B for mm/dd/yyyy.
Once the telemetry gets opened by excel it is not going to work in Helmut’s telemetry analysis program. Delete what you have copied to the computer so far.
Connect the ST-10+ to the PC via a USB data cable. The storage on the ST-10 should then be accessible in File Explorer. Find the FlightLog folder and copy it to your Desktop. Now right click on the copy and select Send To, then select compressed folder. In the box that comes up name it SkySpyFL.zip. You should then have a file on the desktop named SkySpyFL.zip. Now click on the Attach files button and select the SkySpyFL.zip file. This is actually a little better as we will then have the Remote and RemoteGPS files to aid in the analysis.