Battery charging cycles: How to maximise the service life of your e-fleet and reduce TCO
The number of charging cycles is a decisive lever for managing the total cost of ownership (TCO) of your e-fleet. Incorrect charging behaviour can significantly shorten the service life of a 110 kWh battery. Understand the key factors and safeguard the residual value of your vehicles.
The topic briefly and concisely
A charging cycle is the use of 100% of the battery capacity, often made up of several partial charges, not a single charging process.
A charging window between 20% and 80% SoC protects the battery and can significantly extend its service life compared with constantly charging to full.
HEERO eDrive systems with 110 kWh or 137 kWh batteries and intelligent BMS are designed for maximum charging cycles and minimum TCO for fleets.
For fleet operators, battery service life is a key factor in economic efficiency. Every charging cycle affects degradation and therefore directly influences Total Cost of Ownership (TCO). Modern lithium-ion batteries are designed for 1,000 to 3,000 charging cycles, enabling high mileage. However, only an optimised charging strategy and an intelligent Battery Management System (BMS) can fully realise this potential. This article shows you how to maximise the number of usable charging cycles for your battery, reduce operating costs and secure your fleet’s operational readiness in the long term.
Understanding the fundamentals of charging cycles and interpreting them correctly
A charging cycle does not correspond to a single charging process, but to the complete discharge and recharge of 100% of the battery capacity. This process can consist of several partial charges. For example, if you charge the 110-kWh battery of a HEERO eTransporter twice from 30% to 80%, this adds up to one full charging cycle in total (2 x 50% = 100%). This definition is crucial for understanding the manufacturers' specifications on service life. Modern batteries in commercial vehicles typically achieve 1,000 to 3,000 charging cycles before their capacity drops below 80%. A clear understanding of the State of Charge (SoC) is therefore the basis for any optimisation. The type of use is a key factor in determining how quickly these cycles are reached.
Cyclic vs calendar ageing: the two drivers of degradation
Battery ageing is determined by two primary processes that occur in parallel. Cyclic ageing is caused by use, i.e. charging and discharging the battery cells. Each charge cycle causes minimal physical and chemical changes, which accumulate over thousands of cycles. Calendar ageing, on the other hand, occurs independently of use and is influenced by time, temperature and state of charge (SoC). Storage at 30 °C can already double calendar ageing compared with 20 °C. Similarly, persistently high or very low states of charge of above 80% or below 20% accelerate chemical degradation. For fleet managers, it is important to take both ageing types into account in order to preserve the battery health status (SoH) in the long term. These factors are crucial for forecasting the residual value of your vehicles.
Implement charging strategies to maximise the number of cycles
By adapting charging strategies, the usable cycle count of a battery can be significantly increased. The most important rule is to avoid extreme states of charge in day-to-day operation. A charging window between 20% and 80% SoC has proven optimal and can extend cell life by years. Full charges to 100% should only be carried out before long-distance journeys, and the vehicle should then be driven again promptly. Charging speed also plays a role. Frequent DC rapid charging at high power places greater thermal and chemical strain on the battery than slower AC charging at the depot. A study showed noticeably greater degradation after 200,000 km in vehicles with a high share of rapid charging. An intelligent mix of depot and rapid charging is the key.
Optimise the charging window: Keep the state of charge between 20% and 80% during normal operation.
Plan full charges: Only charge to 100% when needed, ideally directly before departure.
Prioritise AC charging: Use gentle overnight depot charging as the standard.
Use DC charging intelligently: Deploy rapid chargers selectively on long routes, not in daily operation.
Manage temperatures: Park vehicles in the shade in summer and use preconditioning.
These measures reduce stress on the battery cells and maximise their service life.
The role of the battery management system (BMS) in long-term durability
A modern battery management system (BMS) is the brain of the battery and crucial for its protection and longevity. It continuously monitors the voltage, current and temperature of each individual cell. The BMS prevents critical conditions such as deep discharge, overcharging and overheating, which would lead to irreversible damage. A key function is “cell balancing”, in which the HEERO BMS actively equalises the charge states of the individual cells. Without this balancing, small differences between the cells would be amplified over the charging cycles and prematurely reduce the battery’s total capacity. HEERO relies on a robust BMS in its self-developed eDrive System, which is specifically designed for the high demands of commercial use. It optimises every charging process for maximum efficiency and minimal degradation. This secures your investment in fleet electrification in the long term.
Economic impact of charging cycles on TCO
Optimising charging cycles has direct financial benefits and lowers the Total Cost of Ownership (TCO) of your fleet. A longer battery lifespan means replacement is needed later and less frequently, one of the most expensive components of an electric vehicle. This significantly reduces maintenance and repair costs over the vehicle's service life. A good battery state of health (SoH) also secures a higher residual value for the vehicle, which has a positive effect on leasing rates and resale value. Fleet managers can significantly reduce operating costs through data-driven charging management. Analysing the charging times and costs is an important step in this process.
Reduced capital expenditure: A maximised cycle count pushes back the timing of an expensive battery replacement by years.
Lower operating costs: Gentle charging lowers energy consumption through greater efficiency and reduced cooling requirements.
Higher residual value: Vehicles with demonstrably good battery health achieve prices on the used market that are significantly higher.
Maximum availability: Healthy batteries ensure daily readiness and range for the vehicles.
A well-considered charging strategy is therefore not a technical detail, but a key instrument for cost control.
HEERO's approach: ensuring longevity through integrated, holistic development
HEERO addresses the challenge of battery life with a holistic approach from its in-house R&D Excellence Center in Munich. At the centre are generously dimensioned batteries designed for the demanding cycles of commercial use. Thanks to their high capacity, only small charging top-ups are often needed in everyday use, which significantly reduces cyclic ageing. Our eDrive system for every type of Mercedes-Benz Sprinter (model 907) is completed within a maximum of 10 working days and, in the case of D2E conversions (Diesel-to-Electric), even preserves valuable specialist bodywork. The intelligent HEERO battery management system ensures optimal thermal management and precise cell balancing, maximising service life. We focus on the TCO benefits and the rapid fulfilment of the Clean Vehicles Directive (CVD), by providing a durable and economical solution for your existing fleet. This safeguards the residual value of your vehicles and sustainably reduces operating costs.
More useful links
Fraunhofer ISI provides a fact check and recommendations for action on batteries in electric cars in this policy brief.
The P3 Group provides a white paper on the state of health (SoH) of batteries.
NOW GmbH provides an overview of studies on the total cost of ownership (TCO) of climate-friendly commercial vehicles.
The Federal Ministry for Transport and Digital Infrastructure (BMV) presents a sub-study on fuel cell lorries as part of scientific research.
The VDE provides data available for download relating to climate-friendly commercial vehicles.
The Federal Office for Logistics and Mobility (BALM) provides information on the Climate Action and Mobility (KSNI) funding programme.
The German Environment Agency offers comprehensive information on climate protection in transport on its topic page.
FAQ
How many charging cycles does a modern commercial vehicle battery last?
Modern lithium-ion batteries in commercial vehicles are typically designed for 1,000 to 3,000 full charging cycles. At a range of 400 km per cycle, this corresponds to a theoretical total mileage of 400,000 to over 1,200,000 km before the capacity falls below 80% of the original value.
Does daily rapid charging shorten the battery's lifespan?
Yes, frequent and exclusive rapid charging (DC) can accelerate battery ageing. The high currents and the heat generated place greater strain on cell chemistry than slower AC charging. For maximum service life, it is advisable to use rapid charging selectively for long-distance journeys and to prefer gentle depot charging in everyday use.
What is the difference between gross and net battery capacity?
Gross capacity is the total amount of energy physically installed. Net capacity is the portion that can actually be used. Manufacturers reserve a buffer (typically 5–10%) to protect the battery from harmful deep discharge and overcharging. This buffer is managed by the BMS and makes a significant contribution to service life.
Does the outside temperature affect the number of charging cycles?
Temperature primarily affects calendar ageing and charging efficiency, not the number of cycles directly. Extreme heat (above 30 °C) permanently accelerates chemical ageing. Severe cold temporarily reduces available power and increases charging time. Good thermal management, as used by HEERO, is therefore crucial.
What warranty does HEERO offer for the battery?
HEERO offers comprehensive warranty coverage for the components installed in all HEERO eDrive systems, including the battery system. The exact terms are designed for demanding use in commercial fleets and provide long-term protection for your investment. Contact us for a detailed fleet analysis and specific warranty details.
Can I check my battery's condition myself?
The exact battery condition (State of Health, SoH) can only be read accurately using specialist diagnostic equipment. The vehicle display shows the state of charge (State of Charge, SoC). For a professional assessment, for example as part of fleet management or before a sale, specialist providers such as the Flying HEEROs offer a detailed analysis.
