Temperature effects on batteries
The main capabilities of batteries that are affected by temperature are performance, lifespan, and safety. However, the way that these metrics are affected depends on the temperature, high heat changes a battery in different ways than if it was very cold. First, let us focus on how high temperatures can affect battery performance.
Battery capacity (how many amp-hours it can hold) is reduced as temperature goes down, and increased as temperature goes up. This is why your car battery dies on a cold winter morning, even though it worked fine the previous afternoon. If your batteries spend part of the year shivering in the cold, the reduced capacity has to be taken into account when sizing the system batteries. The standard rating for batteries is at room temperature 25 degrees C (about 77 F). At approximately -22 degrees F (-30 C), battery Ah capacity drops to 50%. At freezing, capacity is reduced by 20%. Capacity is increased at higher temperatures – at 122 degrees F, battery capacity would be about 12% higher.