For lead-acid batteries, including sealed, Gel, and AGM types, higher temperatures reduce lifespan. Specifically, for every 15 degrees Fahrenheit above 77°F, battery life decreases by half.
What temperature should a battery be?
The ideal battery temperature for maximizing lifespan and usable capacity is between 15 °C to 35 °C. However, the temperature where the battery can provide most energy is around 45 °C. University research of a single cell shows the impact of temperature on available capacity of a battery in more detail.
Under normal conditions, the surface temperature of a lithium-ion battery can reach around 60 to 85 degrees Celsius (140 to 185 degrees Fahrenheit) during charging or discharging. In an overcharging or short-circuit scenario, the battery temperature can increase rapidly.
Proper storage of lithium batteries is crucial for preserving their performance and extending their lifespan. When not in use, experts recommend storing lithium batteries within a temperature range of -20°C to 25°C (-4°F to 77°F). Storing batteries within this range helps maintain their capacity and minimizes self-discharge rates.
However, the temperature where the battery can provide most energy is around 45 °C. University research of a single cell shows the impact of temperature on available capacity of a battery in more detail. The below data is for a single 18650 cell with 1,5 Ah capacity and a nominal voltage of 3,7V (lower cut-off 3,2V and upper cut-off 4,2V).
For the batteries working under high temperature conditions, the current cooling strategies are mainly based on air cooling , , liquid cooling, and phase change material (PCM) cooling, . Air cooling and liquid cooling, obviously, are to utilize the convection of working fluid to cool the batteries.
SOME FACTS ON THE SUBJECT OF AMBIENT OR OPERATING TEMPERATURE. As a general rule, Banner recommends an operating temperature of max. -40 to +55 degrees Celsius; optimum storage conditions are approx. +25 to +27 degrees Celsius. These criteria apply to all lead-acid batteries and are valid for conventional, EFB, AGM and GEL technology.