You may have heard whispers from your neighbors (or family WhatsApp groups) saying that charging your phone in an electric car can drain the car's battery quickly. They say that the phone's power is sucked from the main battery, so if you do it often, the car can run out of energy quickly. But is it true?

If you think about it, the logic makes sense. Phones do need electricity to charge, and the source is of course from the car. But we need to look at it in more detail: how much power does charging your phone actually consume compared to the battery capacity of an electric car, which averages tens of thousands of watt hours (Wh)? I think it needs to be compared so that it's not just "rumored".

For example, the Tesla Model 3 has a battery of around 57.5 kWh, while the iPhone 12 only needs around 10.7 Wh to charge from 0 to 100%. That means, in theory, one Tesla battery can be used to charge a cellphone more than 5,000 times. So, if you only charge it once or twice during a trip, the power used is actually very small.

However, there is one thing you need to be aware of: if the car is off and you still charge your cellphone, it usually draws power from the 12V battery, not from the main battery. Well, this 12V battery has a smaller capacity and functions for support systems such as lights, central locks, and others. If it is continuously throttled to charge a cellphone when the car is off, this battery can drain faster

So, what if the car is on the road? Well, that's a different story. When the car is on, the electrical system is usually ready to support various light loads such as charging a cellphone, GPS, and even a small laptop. So, the effect on the main power is very minimal and can be said to have no significant effect on battery performance or distance traveled.

No less important, you also have to pay attention to the temperature inside the car when charging your cellphone. If the car is hot and you charge your phone on the dashboard that is directly exposed to sunlight, your phone could overheat. Hot temperatures can accelerate the degradation of your phone's battery, so it's not just the car's power that you have to think about.

Therefore, if you really want to charge your phone in an electric car, the safest thing is when the car is on and running. Avoid the habit of charging when the car is off for a long time, especially if you like to park in hot places. Your phone and car battery will last longer if you know how to use them.

So, after dissecting it together, the myth about charging your phone draining your electric car battery quickly is actually not quite right. The consumption is very small and won't damage your car battery—as long as you know the right time and way to charge it.