A van that will not start at 6 in the morning costs a route. For companies in Al Quoz 4 we would rather test the whole yard once than rescue one van at a time. Each vehicle gets a resting voltage reading, a cranking test and an alternator output check, and you get a plain list of which batteries are weak.
Delivery work is hard on batteries. Dozens of starts a day, engine off at every drop, a tail lift or chiller unit drawing current, and the AC running flat out between stops. A battery that would last 3 years in a commuter car often gives up sooner in a van.