Depot Charging
A fleet electrification strategy where electric vehicles are charged at a central facility (depot) overnight or between shifts, using Level 2 or DC fast chargers managed by software to optimize energy costs, balance grid load, and ensure vehicles are ready for daily routes.
Category: EV FleetPublished June 10, 2026Updated June 12, 2026
Why this glossary page exists
This page is built to do more than define a term in one line. It explains what Depot Charging means, why buyers keep seeing it while researching software, where it affects category and vendor evaluation, and which related topics are worth opening next.
Depot Charging vs. En-Route Charging
For most commercial fleets, depot charging is the preferred electrification model because it mirrors the existing fueling workflow: vehicles return to base, are plugged in, and are ready the next morning. This eliminates mid-route charging stops, gives energy managers full control over charging timing and rate, and concentrates infrastructure investment in a single location. En-route charging (using public or semi-public DC fast chargers during operations) supplements depot charging for vehicles that exceed single-charge daily range or operate from multiple locations — it is rarely the primary model for commercial fleets.
Sizing a Depot Charging Infrastructure
Infrastructure sizing begins with three inputs: the number of vehicles to charge, their battery capacity, and the available charging window. A useful formula: total kWh needed per night = (average daily miles / vehicle efficiency in miles per kWh) summed across all vehicles. For 30 Ford E-Transits averaging 87 miles/day at 2.5 miles/kWh, daily energy need is 30 × 34.8 kWh = 1,044 kWh. With a 9-hour overnight window, average power demand is 116 kW — manageable with 16 × 7.2 kW Level 2 chargers if vehicles charge simultaneously. In practice, smart charging software staggers charge start times so not all vehicles pull maximum current simultaneously, potentially reducing peak demand by 30–50% and avoiding demand charge spikes.
Utility Engagement: The Step Most Fleets Underestimate
Adding significant depot charging load often requires utility infrastructure upgrades — transformer upsizing, service entrance upgrades, potentially new primary distribution lines. Fleet operators consistently report that utility approval and construction timelines (6–18 months for significant upgrades) are the longest lead-time item in a depot electrification project, longer than vehicle procurement or charger installation. Engage your utility's key accounts or large commercial team at the beginning of electrification planning, not after vehicles are ordered. Request a formal load study and review of your existing service capacity as the first step.
Real-World Example: Demand Charge Management at a 25-EV Depot
A municipal transit agency installing 25 BEV paratransit vans faced a projected monthly demand charge increase of $8,200 if all vehicles charged at maximum rate simultaneously during their 7 PM–11 PM return window. Their utility's demand charge was $14.50/kW for monthly peak demand. By deploying a smart charging management system (using OCPP to control each charger's output profile), they configured: 7 PM–9 PM at 3.6 kW per vehicle (low-priority charge top-up), 9 PM–2 AM at full 7.2 kW per vehicle (main charge cycle), and 2 AM–5 AM at 3.6 kW balancing (top-off for early-departure vehicles). Peak simultaneous demand dropped from 180 kW (25 vehicles × 7.2 kW) to 90 kW under the managed profile. Monthly demand charge savings: $1,305/month, or $15,660/year — sufficient to recover the smart charging software cost within 18 months.
- Conduct a utility interconnection study before committing to a charging infrastructure design
- Negotiate a time-of-use (TOU) or EV-specific commercial tariff with your utility before installation
- Size charger count for fleet growth: install conduit and panel capacity for 150% of initial EV count
- Select OCPP-compliant chargers to preserve software flexibility as your CPMS needs evolve
- Ensure vehicle departure times are programmed into the CPMS for departure-ready charging guarantee
- Install revenue-grade energy metering per charger for accurate cost-per-vehicle accounting
- Plan physical infrastructure: cable management, vehicle pull-through vs. back-in stall layout, bollard protection
- Test cold-weather performance of chargers and vehicles before winter operations — some Level 2 units underperform below -10°C