How long does it take to charge up an EV using your charging station?
This depends on several factors, including the type of charger you are using, the rate of charge that your vehicle can accept, and the current state of your vehicle battery.
You can learn more about what is involved in EV charging speeds from this blog post: EV Charging Speed Explained
Why is my EV charging slowly?
Mismatch between charger and car capacity
Not all chargers are created equal, and neither are all EVs. If the charger's output is lower than the maximum power your car can accept, you won't get the fastest speeds. For AC charging, if your car's onboard charger can't handle the full power of the station, you'll be limited by that capacity. For DC charging, your car's battery management system (BMS) may limit charging to not damage the battery.
Cable Amp Limitations
Some DC chargers have cables that are limited to 200A. So if a vehicle has battery voltage of 400V, the charge rate may be limited. For example, if your 400V vehicle is charging on a 180kW charger, but the charger has 200A limited cables, the charge rate will be limited to around 80kW.
Power = Current x Voltage
Power = 200A x 400V = 80kW
State of Charge
As the battery gets closer to full (usually around 80%), the charging speed slows down significantly. This is to protect the battery from damage. Imagine pouring water into a nearly full cup – it needs to go in much slower to avoid overflow. Similarly, forcing a full battery to accept a charge too quickly can generate heat and stress the battery cells.
During AC charging, your vehicle may charge at a constant rate over time, but once it reaches 80-90%, it may slow down.
During DC charging, EVs don't charge at a constant rate. They typically follow a charging curve that delivers the fastest speeds in the middle range (between 20% and 80% SoC). This is because the initial charging focuses on replenishing the readily available energy, while the final stage requires more precise control to ensure a safe and full charge.
Battery temperature
Extreme temperatures can slow down charging to protect the battery. EV batteries prefer mild weather, and the battery management system (BMS) will regulate charging to keep things cool in hot weather or warm things up in cold weather.
Battery health
Like any battery, EV batteries degrade over time. This means they might not be able to accept a charge as quickly as they did when they were new. While this is normal, it can be a factor if you notice a difference in charging times.
Faulty equipment
It's always possible that the charging station itself is malfunctioning. Damaged cables or connectors can slow things down. If you suspect this might be the case, notify the site owner and try a different station. If you are a station owner, you can submit a ticket by emailing techsupport@noodoe.com.