Question: 

What is behind Fluke 1770's battery cover?

Answer: 

Watch this video and see what is behind the battery cover. 

The Li-Ion battery BP 1770 keeps the analyzer running for 1 hour and 15 minutes. Charging time is 3 hours when instrument is switched off, else 8 hours. 
The 32 Gb SD card is included in Fluke 1777 only, and can be installed in Fluke 1773 and 1775