Can a car be started directly while charging?
4 Answers
It is possible to start a car directly while charging, but it may be difficult to start the car during the initial charging phase (when the battery is not fully charged). This is because the charger's voltage does not exceed 15V while charging the battery. When starting the engine, the high current required mainly comes from the battery itself. If the battery is not sufficiently charged, it cannot provide enough starting current, making it difficult to start the car. The maintenance methods for car batteries include: 1. Starting the car periodically to charge the battery; 2. Adding distilled water or a dedicated replenishing fluid when the electrolyte level is low; 3. Regularly checking the small holes on the battery cover to ensure they are ventilated; 4. Inspecting the positive and negative terminals for signs of oxidation; 5. Checking all parts of the circuit for aging or short circuits; 6. Turning off all electrical devices when leaving the car.
With years of experience in car repairs, I've seen it all—never attempt to start the engine directly while charging, as it poses significant risks. When the charger is connected to the battery, a steady current is flowing in. Starting the engine suddenly demands a massive surge of current from the starter, creating a conflict between the two currents that can easily lead to short circuits, sparks, or even minor explosions. I've handled cases like this for customers—blown fuses and chargers, costing hundreds in repairs. In severe cases, it can even damage the Electronic Control Unit (ECU), making repairs even more expensive. The safe practice is to first turn off the charger, unplug the connection, and then start the engine. Additionally, regularly checking for battery aging and terminal corrosion is crucial. Developing good habits can save you both hassle and money.
From an electrical principle perspective, both car charging and ignition are high-current operations. During charging, the charger provides low-speed current to the battery, while ignition requires drawing hundreds of amperes to power the starter motor. If performed simultaneously, the collision of currents in the circuit can cause severe voltage fluctuations, which can easily lead to burnout of internal components in the charger or overheating damage to the battery. In practice, I've found that even some smart chargers claim to support ignition, compatibility issues often arise, such as interference with the engine start module. Therefore, I recommend always disconnecting the charging connection before starting the car, and opting for chargers with protective features for routine maintenance.
I remember my neighbor's lesson when he hurriedly started the car while charging, resulting in engine stuttering and difficulty starting. Later, the charger's indicator lights all went out, and it had to be sent for repair. I asked him why he was in such a hurry, and he said he didn't think much about it. But the mechanic analyzed that current overload had damaged the components. Since then, I never touch the ignition switch while charging—I always remove the clamps first before starting the car to avoid accidents. Developing such small habits is key, and now my battery has been in good condition for three years. By the way, choosing a good brand of charger can reduce problems, but don’t rely solely on features—safety comes first.
