Sony ILCE-7S - Manual (Page 232)

You cannot turn on the product.
After inserting the battery pack into the product, it may take a few moments for the product
to power up.
Make sure that the battery pack is inserted correctly.
The battery pack will discharge by itself even if you do not use it. Charge the battery pack
before use.
Make sure that the battery is NP-FW50.
[287] Troubleshooting Troubleshooting Battery pack and power
The power turns off suddenly.
Depending on the product and battery pack temperature, the product may turn off
automatically to protect itself. In this case, a message is displayed on the product screen
before the product turns off.
[288] Troubleshooting Troubleshooting Battery pack and power
The remaining battery level indicator shows an incorrect
level.
This phenomenon occurs when you use the product in an extremely hot or cold location.
Battery capacity decreases over time and through repeated use. If decreased usage time
between charges becomes significant, it is probably time to replace it with a new one.
[289] Troubleshooting Troubleshooting Battery pack and power
The charge lamp on the product/the CHARGE lamp of
the battery charger flashes when charging the battery
pack.
Make sure that the battery is NP-FW50.