When planning an AGV fleet, buyers often focus on vehicle quantity and payload capacity. Charging infrastructure is sometimes considered later, even though insufficient charging capacity can reduce the number of vehicles available for warehouse operations.

The required number of chargers depends on energy consumption, operating hours, charging strategy, battery capacity, and the time available for charging. It should be calculated from the intended operating schedule rather than selected using a simple charger-to-vehicle ratio.

Start With the Operating Schedule

First, identify how the fleet will operate.

• Number of operating shifts

• Operating hours per day

• Expected missions per vehicle

• Average travel distance

• Typical payload

• Expected idle periods

• Planned charging windows

• Required fleet availability

A warehouse operating one shift may have more charging opportunities than a facility running continuously. The same fleet size can therefore require different charging arrangements.

Understand the Battery and Charger Specifications

Request the exact battery and charger data for the proposed AGV model.

Important information includes battery voltage, rated capacity, permitted charging current, charging time, battery management system requirements, and the charging method supported by the vehicle.

Do not calculate charging capacity using battery capacity alone. The usable energy range and the vehicle's charging limits also matter.

Estimate Daily Energy Demand

Ask the supplier for measured or project-specific energy consumption under representative operating conditions.

Energy use may vary with payload, travel distance, acceleration, lifting activity, floor conditions, and operating temperature.

For a preliminary estimate, multiply the expected energy consumption per operating hour by the vehicle's planned operating hours. The estimate should then be checked against actual operating data during testing.

Calculate Available Charging Time

Charging time is not necessarily equal to the total time a vehicle is scheduled to be idle.

The AGV may need to wait for a charger, travel to the charging point, connect to the charger, complete charging, and return to an operating area.

For opportunity charging, the available windows may be short and distributed throughout the shift. For scheduled charging, the charging period may be more predictable but could temporarily remove several vehicles from service.

Consider Charger Queues

Even if the total charger capacity appears sufficient, several vehicles may request charging at the same time.

This can happen during shift changes, low-battery alerts, or periods when many vehicles complete similar mission cycles.

Ask the supplier how the fleet manager handles charging requests and whether charging can be scheduled according to battery state, task priority, and vehicle availability.

Check Charging Location and Travel Distance

Charger placement affects more than electrical installation cost.

If charging points are far from operating zones, AGVs spend additional time traveling without carrying out warehouse missions.

Review charging locations alongside traffic routes, pedestrian access, emergency exits, and maintenance access. Charging points should not create avoidable bottlenecks.

Evaluate the Electrical Infrastructure

Before ordering chargers, confirm the site's available electrical capacity and installation requirements.

The review should cover charger input ratings, supply voltage, circuit protection, cable routing, ventilation where applicable, and local electrical approval requirements.

The exact requirements depend on the charger design, installation, and jurisdiction. Have the local electrical contractor review the proposed arrangement before installation.

Use a Practical Charging Test

During a pilot or commissioning test, record:

• Battery state before charging

• Energy delivered during charging

• Charging duration

• Time spent waiting for a charger

• Travel time to and from the charger

• Vehicle availability during charging

• Charging interruptions or faults

These measurements can help determine whether the initial charger quantity and locations are suitable for the actual workload.

Plan for Fleet Expansion

If the warehouse may add vehicles later, ask whether the electrical infrastructure and charging layout can support expansion.

It may be possible to reserve electrical capacity or installation space during the initial project, reducing the need for disruptive changes later.

The correct charger quantity is the quantity that supports the required operating schedule with acceptable waiting time and vehicle availability—not simply the number that matches a standard fleet ratio.