Every electric car now comes with a DC Fast Charging option. While most people understand what fast charging is, this knowledge is limited. Before you use a public fast charger, here is everything you need to know about DC Fast Charging to ensure that you don’t harm your battery unknowingly.
What is DC Fast Charging?
AC is Alternating Current and is called so because the flow of electrons continually alternates back and forth. DC is Direct Current and flows in a single, constant direction.
Batteries operate on direct current (DC).
The regular charging slot uses an AC charger which sends power to the Internal Charger (also called the Power Inverter) of the car which turns the alternating current to direct current and delivers power to the battery.
DC chargers use the two larger pins below the regular charging slot to bypass the Internal Charger in the electric vehicle. This allows the DC charger to deliver a much higher current to the battery. Most DC fast chargers deliver upwards of 100 kW as compared to the 11 kW of AC fast charger.
How Long Will it Take to Charge Your EV?
Charging time depends on your battery capacity and the power input.
Let’s take Tata Harrier EV for a second. It has a battery pack of 75 kWh, which means it can supply 75 kW power for an hour. It comes with a 7.2 kW AC fast charger, which means it can take up to 10 hours and 42 minutes to fully charge the battery.
Now, if we connect it to a 120 kW DC fast charger, this time goes down significantly to just about 25 minutes (for charging from 0% to 80%).
How Fast Can Your Car Charge?
Well, this depends entirely on the charging curve of your car battery. The charging curve determines how long the battery can sustain the input of peak power.
Let’s take the example of Hyundai Ioniq 5 and BMW i4.
BMW i4 has a 70.2 kWh battery pack and can use a 200 kW DC Fast Charger to go from 0% to 80% in 31 minutes.
On the other hand, Ioniq 5 has a similar battery pack of 72.6 kWh and can use a 150 kW DC Fast Charger to go from 0% to 80% in just 21 minutes.
The difference is significant despite the Hyundai using a lower power DC charger. This is because of the charging curve, where as the state-of-charge (SOC) increases, the charging rate decreases. Since Hyundai can sustain that power for a longer time compared to BMW, it shortens its charging time significantly.
This is why the DC Fast Charging time can differ between brands, despite having a similar battery pack.
The charging curve dips down regardless of the brand past the 80% mark, which is why DC Fast Charging is only calculated till 80%. Charging beyond that will take significantly longer and is not practical at public charging stations.
It is important to know the peak power your battery can handle so you’re not using a charger that could potentially damage your battery.
How to Find a DC Fast Charger Near You?
This is really quite simple since there are multiple charging stations in India and you can check every single one right here. It can tell you the number of chargers at that station, the type of charger it offers, and how much power it can deliver.
One of the innovations that we have seen in India is the inclusion of public charger information in the infotainment system for an easier trip plan.
How to Activate a Public Charger?
Most public chargers use a mobile app or an RFID card to initiate payment. These apps have an in-app wallet which can be recharged through online payments. Similar concept applies for the RFID card.
You need to tap the card or initiate payment on the app first to start the charging of your electric vehicle. The reason for a card or wallet is that the final price is determined by how long your vehicle is charged.
How Much Does it Cost?
Most chargers in India charge by the power, with most rates between ₹10 to ₹22 per kWh. This can reduce and inflate depending on the type of charger and location.
With Tata Harrier EV, if you are at a 10% SOC (State-of-Charge) and you charge up to 80% SOC, the highest it will go is around ₹1,100. On the flip side, if the charging cost is less, you’ll only be paying around ₹500 for the charging.
Home charging is usually recommended unless you don’t have that option.
Want to know more about EV Chargers? Check out this Blog.
