High Temperatures
WARNING: This page is about a different car, the 2010 Volvo V70, 2009 Volvo V70, and 2008 Volvo V70. However, it is still accessible from the selected car via links, so may be relevant.
A high ambient temperature speeds up the chemical processes in the battery during charging and discharging. For every 10°C (18°F) increase in temperature, the reaction speed of the processes doubles. The risk of corrosion, self-discharge and sulfation increase at a high temperature and the service life of the battery is reduced. The service life of a battery improves in colder surroundings.