If the car doesn't start after winter, it’s often not the cold, but the high temperatures from the previous summer that are to blame. What happens to the battery during the summer? It’s an experience most drivers have had: they get in their car, turn the key, and nothing happens. Diagnosis: dead battery. However, contrary to popular belief, it's not the cold that stopped the battery from working, but the warm temperatures from the previous summer. Main Causes of Battery Failures Battery failures have two main causes: wear and aging. Wear is easy to understand by looking at the car tires: the more you drive and the harder your driving style, the faster the wear. The same applies to the battery: the more frequently and deeply the battery discharges, and the more electrical consumers drain the battery, the greater the wear. Also, if you use your car infrequently or mainly for short distances, the alternator cannot fully charge the battery, while electrical consumers continue to discharge it. This can be addressed with the right battery technology. For example, if you have a vehicle with a start-stop system, AGM or EFB technology is absolutely required. A conventional SLI battery (starter, lights, ignition) is not designed for these applications and thus wears out quite quickly. The power of an AGM battery can also benefit cars without a start-stop system: AGM technology provides larger power reserves, which benefit conventional vehicles without a start-stop system by offering a longer battery life. An AGM battery can also withstand extreme external temperatures, while a conventional starting battery reacts to extreme cold and heat with rapid capacity loss and discharges faster. This was proven in a field study in Dubai, where vehicles with start-stop systems equipped with conventional batteries all failed after 5 to 6 months, while the comparative fleet equipped with AGM batteries remained functional until the end of the test after 12 months. It is not possible to make generalized statements regarding lifespan and aging process, as lifespan depends on factors such as battery type, ambient temperature, number of cycles, depth of discharge, or frequency of use. However, wear ultimately affects the aging process and therefore the battery’s lifespan. Summer heat accelerates the aging process.