Intralogistics Automation

AGV Fleet Sizing and Charging Strategy: Right-Sizing Your Autonomous Fleet

AGV charging strategy determines how many vehicles you need and where to place charging stations. Here is how to calculate charging requirements and balance fleet size against charging infrastructure.

AGV charging strategy is either block charging (full recharge after each shift) or opportunity charging (short charges during natural pauses in operation). Block charging: each vehicle needs full charge each shift. Charging time for a typical 24V/200Ah AGV at standard 20A charge rate = 10 hours. This means block charging is only practical for 2-shift operations where the vehicle has an off-shift to charge. For 3-shift operations or continuous processes, opportunity charging is required.

Opportunity charging station count = (peak fleet operating count) / (operating cycles per charge event). If each vehicle stops to charge for 15 minutes every 2 hours of operation, and the fleet has 10 vehicles running: vehicles at charging stations at any time = 10 x (15/120) = 1.25 vehicles. You need at minimum 2 charging stations for the fleet. Add 50% buffer for traffic and timing: 3 stations. Each charging station costs $1,500-$8,000 depending on current capacity and connector type. Infrastructure cost for 3 stations: $5,000-$25,000.

Lithium-ion AGV batteries enable opportunity charging more effectively than lead-acid. Li-ion accepts fast charge at 1C-2C rate (full charge in 30-60 minutes) versus lead-acid which must charge at C/10 rate (10-hour charge, damages battery if faster). Li-ion also has no memory effect and handles partial charge cycles without degradation. Li-ion AGV battery replacement cost is $3,000-$8,000 per pack with 2,000-3,000 cycle life. Lead-acid replacement cost is $800-$2,500 but with shorter cycle life in opportunity charging service.

Charging station placement affects AGV utilization and traffic flow. Stations should be placed: near the most common resting positions (staging areas, buffer zones), distributed across the facility to minimize travel distance for charging, and not in path-critical corridors that would block traffic while a vehicle charges. Poor station placement adds 5-15 minutes per charge cycle in travel time, reducing effective fleet utilization. Model traffic flow before committing to station locations.

Fleet size calculation must include charging overhead. If 20% of vehicle operational time is unavailable due to charging (block charging with 10-hour charge / 8-hour shift x unavailability ratio), and you need 8 operational vehicles at all times, actual fleet needed = 8 / (1 - 0.20) = 10 vehicles. For opportunity charging at 12% overhead: 8 / 0.88 = 9.1, round to 10. The difference between block and opportunity charging in this example is 1 vehicle ($50,000), which may or may not offset the infrastructure cost difference.

Published 2026-05-28.