Lead-Acid Batteries: Although modern starter batteries have become more heat-resistant, a temperature increase of around 12°C (22°F) can still reduce their lifespan by …
Lead acid batteries function using an electrochemical process in which lead plates react with an electrolyte. As the temperature rises and a battery absorbs heat, the process speeds up exponentially. This results in an increase in plate corrosion, self-discharge, and over a prolonged period of time, sulfation.
Thermal events in lead-acid batteries during their operation play an important role; they affect not only the reaction rate of ongoing electrochemical reactions, but also the rate of discharge and self-discharge, length of service life and, in critical cases, can even cause a fatal failure of the battery, known as “thermal runaway.”
Extreme heat speeds up the chemical reaction inside a battery and causes an increase in the self-discharge and plate corrosion. This leads to sulfation which can cause irreparable damage to the battery. For each 10°F rise in temperature, the life of a sealed lead acid battery is cut in half.
Heat issues, in particular, the temperature increase in a lead-acid battery during its charging has been undoubtedly a concern ever since this technology became used in practice, in particular in the automobile industry.
For each 10°F rise in temperature, the life of a sealed lead acid battery is cut in half. Therefore, if a battery in a stationary position that should last for 4 years at normal temps, would last 2 years if exposed 92°F and even less if exposed to typical desert temps of 106°F. In some areas, heat is unavoidable.
Thus, the maximum voltage reached determines the slope of the temperature rise in the lead-acid battery cell, and by a suitably chosen limiting voltage, it is possible to limit the danger of the “thermal runaway” effect.