Recently carried out a test on the battery life for the T420
Results are listed below only as a guide. The Camera was turned off and only turned on to assess the battery life using the cameras battery symbol.
08:10 – Inserted fully charged battery, turned camera on, made sure battery symbol was full, then turned camera off.
11:10 – Turned camera on and battery symbol was on 3/4 full.
13:10 – Battery 1/2 full
15:10 – Battery 1/4 full
17:10 – Battery symbol flashing
18:10 Battery empty.
Be aware of battery drain even when battery is inserted and camera is not turned on.