Service life of a battery
Average lifespan by technology: SLI 3-5 years, EFB 5-7 years, AGM 6-8 years. Warm climates cut 1-2 years.
The service life of an automotive battery depends on three factors: technology, conditions of use, and climate. Reasonable average: conventional lead-acid SLI 3-5 years, EFB 5-7 years, AGM 6-8 years, GEL deep cycle 7-10 years, LFP lithium 10-15 years. In warm climates (south of Spain, Italy, Portugal) subtract 1-2 years — heat accelerates internal corrosion. In very cold climates (regularly below -10°C) the battery suffers from cold-start difficulty but lasts the same or longer. Other factors that reduce life: repeated short trips (no full charge), high parasitic loads (alarm, GPS, keyless entry), starting with corroded terminals (poor recharge).
Factors that extend life: regular long trips, trickle charger during inactive periods, climate-controlled battery placement (some premium brands fit the battery in the interior of the cabin precisely for this reason). End-of-life symptoms: slow cold cranking, lights flickering on starting, Start-Stop disabled, battery hot to the touch, swollen case.