Is 22 kW AC charging enough for commercial vehicle fleets? A TCO analysis
Fleet managers face the decision: is 22 kW AC charging at the depot sufficient, or are expensive DC fast chargers necessary? The answer lies in analysing dwell times and total cost of ownership (TCO). For over 90% of use cases, the AC solution is not only sufficient, but clearly superior.
The topic briefly and concisely
For a 110 kWh battery, charging time at a 22 kW AC charging station is only 5 hours, which is entirely sufficient for overnight downtime of 8–12 hours...
The purchase and installation costs of 22 kW AC wallboxes are significantly lower than those of DC fast-charging stations.
Intelligent load management avoids costly grid connection upgrades and ensures that all vehicles are ready for service in the morning.
Electrifying commercial vehicle fleets is not a question of whether, but how. A key, often overlooked lever for profitability is the charging strategy. While DC fast charging (direct current) promises high power, fleet operators face the pragmatic question: is it actually necessary for day-to-day operation in the depot? The analysis shows that charging at 22 kW alternating current (AC) is generally the smarter choice. It optimises the Total Cost of Ownership (TCO), protects the battery and ensures vehicle readiness – exactly where they spend most of their time: overnight in the depot.
Charging time analysis: 5 hours for a full shift
The key question of charging infrastructure can be answered mathematically. A HEERO D2E Sprinter with a 110 kWh battery requires exactly 5 hours at a 22 kW AC wallbox for a full charge (110 kWh / 22 kW). Typical commercial vehicles in municipal or last-mile use have overnight downtimes of 8 to 12 hours. This leaves more than enough time for a full charge. This simple calculation shows that no higher charging capacities are required for overnight depot charging. The vehicles are fully ready for use every morning with 100% capacity and up to 425 km range. Operational reliability is thus fully assured, without having to invest in more expensive infrastructure. This efficiency in downtime utilisation is the first building block towards reducing TCO.
TCO benefit of AC charging: significantly lower infrastructure costs
The decision between AC or DC charging has a major impact on total cost of ownership. AC wallboxes are significantly cheaper to purchase and install than DC rapid charging stations. The costs of DC systems can quickly be five to ten times higher, especially when a new medium-voltage connection is required. Moreover, slower AC charging is gentler on the battery, which extends the lifespan of the 110 kWh battery and preserves the vehicle's residual value. The savings on infrastructure can add up to tens of thousands of euros per site.
The key cost advantages of 22 kW AC charging at a glance:
Lower hardware costs: A 22 kW wallbox costs only a fraction of a 50 kW DC charger.
Reduced installation costs: Connection to the existing low-voltage grid is often possible without expensive grid expansion.
No charging losses: Modern AC systems operate with an efficiency of over 95%.
Longer battery life: Gentle charging cycles significantly reduce the degradation of battery cells over the vehicle's service life.
These factors make 22 kW AC charging the most economical method for predictable charging in the depot.
DC rapid charging: the exception, not the rule
Despite the advantages of AC charging, DC charging also has its place, albeit in a different role. DC charging is intended for “Opportunity Charging” – rapid top-up charging on the move to extend range on unforeseen routes. The HEERO D2E-Sprinter can charge with up to 165 kW DC and thus reaches an 80% state of charge in just 60 to 90 minutes. This is ideal for vehicles operating on a two-shift basis or on very long, unscheduled routes. For over 90% of fleets, however, this is a rare use case. The strategic question is not AC or DC, but the right balance. The basis is usually cost-effective AC charging at the depot. DC charging is a supplement for specific operational peaks, not the basis for day-to-day operations.
Ensuring grid stability: intelligent load management as the key
If a whole fleet charges simultaneously at 22 kW, the grid connection capacity can quickly reach its limits. Ten vehicles would simultaneously require 220 kW of power. An intelligent load management system is the solution here. It distributes the available power dynamically to the connected vehicles. This ensures that the depot's maximum connection capacity is never exceeded, while still ensuring that all vehicles are fully charged by morning. Such a system avoids costly load peaks and can significantly reduce annual grid fees.
The process of intelligent load management typically runs through these steps:
Analysis: The system records the State of Charge (SoC) of each individual vehicle battery.
Prioritisation: Vehicles with low SoC or an earlier departure time are prioritised.
Distribution: The available total power is allocated in stages and dynamically distributed to the vehicles.
Monitoring: The charging process is continuously monitored and adjusted to stabilise the grid.
HEERO offers comprehensive depot charging consultancy to plan such a customised and cost-efficient charging infrastructure.
CVD compliance and operational reliability through predictable charging
The EU’s Clean Vehicles Directive (CVD) is placing considerable pressure on public contracting authorities and their service providers to decarbonise their fleets. Procurement targets for clean commercial vehicles stand at 38.5%. A reliable charging infrastructure is the foundation for meeting these legal requirements and maintaining operations. Depot infrastructure based on 22 kW AC charging offers maximum operational reliability. The vehicles are ready for deployment every day as planned. This reliability is a decisive factor in fulfilling service contracts and avoiding contractual penalties. HEERO’s D2E conversion, combined with thoughtful charging planning, ensures that fleet operators not only meet the CVD quotas, but do so in the most economical way.
More useful links
Federal Motor Transport Authority (KBA) offers detailed statistics on e-mobility in Germany.
Federal Ministry for Digital and Transport (BMDV) provides information on commercial vehicles with alternative drives in the context of climate protection in transport.
National Charging Infrastructure Coordination Centre provides information and resources specifically for commercial vehicles.
NOW GmbH provides an overview of studies on the total cost of ownership (TCO) of climate-friendly commercial vehicles.
The International Council on Clean Transportation (ICCT) highlights, in a factsheet, the total cost of ownership (TCO) of battery-electric commercial vehicles in Europe, with a focus on Germany.
Federal Network Agency provides comprehensive information on e-mobility.
FAQ
Is 22 kW AC charging sufficient for any fleet size?
Yes, a charging capacity of 22 kW is generally suitable for fleets of any size. What matters is not the output per vehicle, but intelligent load management that distributes the total capacity of the grid connection optimally across the vehicles. This means that 20 or more vehicles can also be charged reliably overnight without overloading the electricity grid.
What happens if my vehicle can only charge at 11 kW AC?
A 22 kW wallbox is backwards compatible. If your vehicle only supports a charging capacity of 11 kW, it will also only charge at this rate. The charging time for a 110 kWh battery then doubles to around 10 hours, which is generally still more than sufficient for most overnight idle periods. However, investing in 22 kW infrastructure is future-proof.
Do I need approval for 22 kW wallboxes?
Yes, in Germany charging installations with a power output of more than 11 kW must be approved by the responsible grid operator before installation takes place. This helps ensure grid stability. HEERO supports these processes as part of depot charging consultancy, helping to ensure smooth planning and commissioning.
Does frequent 22 kW charging damage the vehicle battery?
No, charging at 22 kW AC is considered standard charging and is very gentle on the lithium-ion battery. Compared with DC fast charging at 165 kW or more, it creates significantly less thermal stress, which slows cell ageing and maximises the battery’s service life. This has a positive effect on the vehicle’s TCO and resale value.
How high are the charging losses when charging with 22 kW AC?
Modern on-board chargers in vehicles such as the HEERO D2E Sprinter work very efficiently. Charging losses during conversion from alternating current to direct current are typically only 5 to 8%. That means that of the 22 kW of power supplied by the wallbox, over 20 kW are fed directly into the battery. This is an excellent figure for energy efficiency.
Can I also combine DC chargers with a 22 kW charging infrastructure?
Yes, a hybrid charging infrastructure is often a sensible strategy. The basis for predictable overnight charging is provided by the cost-efficient 22 kW AC wallboxes. For operational emergencies or vehicles in multi-shift operation, a single DC fast charger can be installed as a “joker” option. HEERO analyses your individual requirements and plans the optimal combination.
