The major cost in any EV goes into the battery. It’s like the heart of an EV, much like how engines are for fossil fuel-powered vehicles. Hence, it’s important to make sure that your battery is not overstressed. To do so, you should know the various aspects of charging your EV. In this blog, we cover why the charging speed goes down as soon as the battery level reaches 80%. This is something you would have noticed mostly at public charging stations. Let us explain the reason behind this.
When you pour coffee into your cup, initially, since it’s empty, you pour it fast. But as the coffee reaches 80% of the cup, you tend to slow down the speed at which you were pouring earlier. This is similar to how charging your EV’s battery works.
Initially, it charges your EV at a faster speed, but as the battery level reaches 80%, the charging speed slows down. This is done to protect your battery and increase its efficiency. At a higher battery level, the lithium ions have to squeeze into an already nearly full anode, making this process slower and more energy-intensive.
Excessive heat can damage your EV’s battery, leading to a reduced lifespan. To mitigate this, the battery management system (BMS) reduces the charging speed at higher battery levels to maintain safe operating temperatures. Slowing down the speed at higher battery levels prolongs the battery’s lifespan and maintains its performance. The final 20% is called the saturation phase.
Charging speed is totally different from battery capacity. If your vehicle’s battery capacity is, say, 60kWh, the charging speed will not necessarily be 60kW. For instance, the Mahindra XUV 400 EV comes with battery capacities of 34.5 kWh and 39.4 kWh, with a charging speed of 54 kW. Read more about the difference between battery capacity and charging speed.
So, the next time you charge your EV at public charging stations, avoid charging at DC fast chargers beyond 80%. This will not only protect your EV’s battery from damage but also allow the next EV to charge sooner. You’re saving time for yourself and other EV owners.