Home > Newsroom > Technical Knowledge > FAQ: Why is my EV not charging as fast as before?

FAQ: Why is my EV not charging as fast as before?

The charging speed of an electric vehicle (EV) can vary due to several factors that impact the efficiency of the charging process. Understanding these factors is crucial for optimizing charging times and ensuring the longevity of the vehicle’s battery. This article explores the key elements that affect the charging speed of EVs at EV charging stations.


Optimal Charging with Low State of Charge (SoC)

EVs charge most rapidly when the battery is nearly depleted, with a low State of Charge (SoC). As the battery fills up, the charging speed decreases due to the increasing difficulty for electrons to find available spaces within the battery cells.

Solution: For optimal battery life and charging efficiency, it is recommended to charge the EV battery within the 20% to 80% State of Charge (SoC) range. Charging below 20% or above 80% can have a detrimental impact on battery longevity due to stress on the separator membranes in lithium-ion batteries. Maintaining the battery’s SoC within the recommended range helps to minimize stress on the separator membrane, thereby extending the battery’s lifespan and ensuring optimal charging performance, especially when using DC fast charging.


Impact of Battery Temperature on Charging Efficiency

Like most electronic devices, EV batteries perform optimally within a specific temperature range. Extreme temperatures, whether too hot or too cold, can trigger safety mechanisms within the Battery Management System (BMS) to protect the battery’s health and longevity. The BMS may limit charging speeds in these conditions to prevent potential damage, resulting in prolonged charging times.


Effects of Simultaneous Charging on Speed

EV charging stations that allow multiple EVs to charge simultaneously may experience reduced charging speeds for each vehicle. This is because the available power must be shared among the connected vehicles, leading to a decrease in the individual charging rate for each EV.

Solution: To mitigate the impact of multiple EVs charging simultaneously on individual charging speeds, charging station operators should implement “dynamic power allocation management” techniques. These smart charging technology systems can dynamically allocate available power based on the State of Charge (SoC) levels of the connected vehicles, ensuring that each EV receives the maximum possible charging rate, even during periods of high demand.


Influence of In-Vehicle Energy Consumption on Charging Time

While charging, using in-vehicle systems such as climate control, audio systems, or interior lighting can divert energy away from the charging process, especially in AC charging. This additional energy consumption can lead to an increase in overall charging time, as some of the power is being utilized by the vehicle’s auxiliary systems rather than solely dedicated to battery charging.

Solution: While an EV is charging, it is recommended to minimize the use of in-vehicle systems that consume energy, particularly when using DC fast charging. By minimizing unnecessary energy consumption during charging, EV owners can ensure that the maximum available power is dedicated to charging the battery, resulting in faster charging times.

*While some energy drain is inevitable due to essential systems, being mindful of auxiliary energy usage can typically reduce charging times by 5-10%.


Vehicle Software Updates

Software updates issued by EV manufacturers can have a significant impact on the vehicle’s charging speed. These updates often include modifications to the Battery Management System (BMS), which governs how the battery charges and discharges. While these updates are intended to improve overall vehicle performance and safety, they can sometimes result in changes to the charging algorithm, affecting charging speed.

Solution: It is essential to regularly check for and install software updates to ensure your vehicle is operating with the latest improvements and protections. However, if you observe a noticeable decrease in charging speed following an update, it is important to reach out to the vehicle manufacturer. They can provide insights into the changes brought by the update and offer solutions or adjustments if necessary. Smart charging technology at EV charging stations can often adapt to these updates to maintain optimal charging performance.


By understanding these factors, EV owners can optimize their charging strategies and ensure efficient charging times. Proper battery management, temperature control, and judicious use of in-vehicle systems during charging can contribute to a more seamless and efficient charging experience, especially when utilizing DC fast charging and smart charging technology at EV charging stations.

Contact ZEROVA

Saving Energy , Charge The World

ZEROVA offers high-quality, economical fast chargers, customized EV charging solutions, and infrastructure consulting services for a variety of business sectors. Contact us now for details.