How Long Does a Car Battery Last Without Use?

A car battery will typically lose its charge after about 2 months of inactivity. The battery discharges at a rate of approximately 1% per day. If left connected to the car without removal, the vehicle draws a minimum current (commonly known as "standby" current) of around 80mA to maintain basic functions. If the car has an anti-theft alarm, it will consume additional power.

Signs that a battery replacement is needed: Under normal circumstances, if the vehicle suddenly becomes difficult to start, it may be a sign that the battery is nearing the end of its life; dimming headlights at idle; the battery warning light illuminating; unusual noises from the starter due to weakened battery discharge capacity; or visible bulging or leakage from the battery.

Battery maintenance tips: Regular inspections are an effective way to extend a car battery's lifespan; clean the positive and negative terminals with a specialized battery brush or an old toothbrush to remove dust and corrosion; apply petroleum jelly or a similar protective substance to the contact surfaces to create a protective film.