https://www.quora.com/How-much-mAh-does-a-standard-car-battery-have
For common car batteries, it varies from about 30 AH (30,000 Mah) for the smallish batteries used in many Asian and European small cars, to around 50 AH (50,000 Mah) in full sized cars, to larger 70 AH (70,000 Mah) batteries in larger pickups and diesel powered vehicles.