Notes on batteries
Never leave the battery in temperatures above 140°F (60°C), such as under direct sunlight or in a car parked in the sun.
While the battery is in use or being discharged, the battery heats up. This is normal and is not cause for concern.
Keep the battery away from heat sources.
Keep the battery dry.
Do not open or disassemble the battery.
Do not expose the battery to any mechanical shock.
Battery life is shorter in a cold environment because of decreased battery efficiency at low temperatures.
Some VAIO personal computers may function only with a genuine Sony battery.
Page 49