{"id":5165,"date":"2025-05-13T12:43:57","date_gmt":"2025-05-13T07:13:57","guid":{"rendered":"https:\/\/evjoints.com\/ev-guide\/?p=5165"},"modified":"2025-05-21T15:34:15","modified_gmt":"2025-05-21T10:04:15","slug":"what-is-an-onboard-charger-in-electric-vehicles-simplified","status":"publish","type":"post","link":"https:\/\/evjoints.com\/ev-guide\/what-is-an-onboard-charger-in-electric-vehicles-simplified\/","title":{"rendered":"What Is an Onboard Charger in Electric Vehicles? Simplified"},"content":{"rendered":"

Imagine bringing home a brand-new electric car like the Tata Nexon EV, MG Windsor EV Pro, or Mahindra BE.06. You park it, plug it into the wall socket or a home charger, and expect it to charge overnight your EV\u2019s battery, just like your phone.<\/p>\n

But what many people don\u2019t realise is there\u2019s a hidden hero inside your EV, quietly doing the real work as a middleman between your AC chargers and battery.<\/p>\n

That hero is called the onboard charger.<\/p>\n

So, What Exactly Is an Onboard Charger?<\/strong><\/p>\n

Let\u2019s say you\u2019re filling a water tank. If you use a garden pipe, it\u2019ll take a while. But if you use a thick inlet pipe, the tank fills up much faster.<\/p>\n

That thick pipe is what the onboard charger represents. The higher its kilowatt (kW) rating, the faster your car can charge using AC power.<\/p>\n

\"What<\/p>\n

For example, if you install a 7 kW wallbox at home but your EV only supports 3.3 kW through its onboard charger, you\u2019ll still be limited to that slower 3.3 kW speed. So it\u2019s not just the charger on the wall that matters\u2014it\u2019s also about what\u2019s built inside your car.<\/p>\n

Why Can\u2019t EV Batteries Use AC Power Directly?<\/strong><\/p>\n

Think of your EV battery like a guest at a dinner party who will only eat food that\u2019s fully cooked and ready to serve. But the electricity from your wall is like raw ingredients\u2014it\u2019s AC (alternating current) and your battery only digests DC (direct current). Know the difference between AC and DC charging<\/a> in depth<\/p>\n

The onboard charger works like the in-house chef. It takes those raw AC ingredients and prepares a nice, cooked DC meal\u2014exactly how your battery likes it.<\/p>\n

DC Fast Charging: How It Bypasses the Onboard Charger<\/strong><\/p>\n

While your onboard charger is the hardworking chef converting AC power into DC, DC fast chargers skip the kitchen altogether. Instead of passing electricity through the onboard charger, DC fast chargers send power directly to your EV\u2019s battery. This is why DC fast charging is significantly faster\u2014because it eliminates the conversion step and delivers high-voltage DC straight to the battery, often at speeds ranging from 50 kW to 350 kW, depending on what your EV supports.<\/p>\n

Think of it like ordering pre-cooked meals instead of cooking from scratch\u2014your battery gets exactly what it needs, instantly.<\/p>\n

Where Is the Onboard Charger Located?<\/strong><\/p>\n

You won\u2019t find it lying around in the boot or glovebox. The onboard charger is built into the EV, usually located under the hood or beneath the floor, close to the powertrain. You\u2019ll never directly interact with it, but every time you plug into an AC charger, it\u2019s doing the conversion quietly in the background.<\/p>\n

How Onboard Chargers Regulate Voltage and Current?<\/strong><\/p>\n

Your onboard charger isn\u2019t just a simple converter\u2014it\u2019s a smart regulator that ensures your battery gets the right amount of power without overheating or overcharging. It dynamically adjusts voltage and current based on the battery\u2019s state of charge.<\/p>\n

Here\u2019s how it works:<\/p>\n