What is the general voltage of a car battery?
2 Answers
Different types of batteries used in cars have different voltages: Nickel-Cadmium Battery: Nickel-Cadmium Battery (Ni-Cd), voltage: 1.2V; service life: 500 cycles; discharge temperature: -20°C to 60°C; charging temperature: 0°C to 45°C. Nickel-Metal Hydride Battery: Nickel-Metal Hydride Battery (Ni-MH), voltage: 1.2V; service life: 1000 cycles; discharge temperature: -10°C to 45°C; charging temperature: 10°C to 45°C. Lithium-Ion Battery: Lithium-Ion Battery (Li-lon), voltage: 3.6V; service life: 500 cycles; discharge temperature: -20°C to 60°C; charging temperature: 0°C to 45°C.
Car batteries are generally 12 volts, which is important to remember. Actually, my friend who runs a repair shop said that to truly assess a battery's condition, you can't just rely on this nominal value—measuring the voltage when the engine is cold is key. For example, if you measure around 12.6V before starting the car in the morning, it indicates a full charge, but if it's below 12.2V, you might have trouble starting. My car once stalled in winter because I didn’t pay attention to the battery level—now I always carry a simple voltage tester. Here’s another lesser-known fact: when the engine is running, the voltage rises to around 14V—that’s the alternator charging the battery. If the battery is severely depleted, not only will the car fail to start, but electronic devices like the infotainment screen may also stop working.
