Does a Dead Car Battery Need Replacement?
3 Answers
1. Jumper Cables: These are essential items for jump-starting a car. Never attempt to use random wires as a substitute, because the instantaneous current during vehicle startup can reach 200-600A, and even up to 1000A for diesel vehicles. Calculated, a 10-square-millimeter copper wire is required to ensure smooth and safe startup. Therefore, always purchase branded, high-quality car battery jumper cables—don't compromise on safety to save money. This is one of the must-have items in your car; it can be used when your battery dies or to help others in need. 2. Emergency Power Source: This is a new portable device similar to a power bank, available in lead-acid and polymer lithium-ion versions. It can assist in jump-starting a depleted battery and also functions as a multi-purpose tool for lighting, charging mobile phones, and inflating tires with an air pump. Typically compact and lightweight, having one eliminates the need to seek help for a jump-start. After use, always recharge it promptly to ensure sufficient power for emergencies. 3. Positive to Positive, Connect Positive First: First, turn off all electrical devices in the car and ensure the key is in the 'off' position. Open the hood and locate the battery, which is clearly marked with positive (+) and negative (-) terminals (usually red '+' for positive). Jumper cables typically come in pairs. Take out the red cable first, open the battery cover, and firmly clamp one end to the dead battery's positive terminal. Then, attach the other end to the positive terminal of the rescue vehicle's battery. Always connect the positive terminal first, followed by the negative. Never reverse this order or let the clamps touch anything other than the battery terminals. 4. Negative to Negative, Connect Negative Last: After securing the red positive cable, take out the other jumper cable. First, clamp it firmly to the dead battery's negative terminal (usually marked with a black '-'). Then, while ensuring the clamp doesn't touch anything else, attach the other end to the rescue vehicle's negative terminal. Don't be alarmed if sparks appear during this step—it confirms the connection is correct. The reason for connecting the negative last is that most conductive metal parts of the car are grounded (i.e., connected to the negative). If the negative is connected first, accidentally touching any conductive part of the car body while attaching the positive clamp could cause a short circuit, damaging vehicle components. 5. After Starting the Vehicle, Remove Negative First, Then Positive: Once the batteries are connected, start the rescue vehicle to charge the dead battery. Then, the driver of the dead vehicle should turn the key to power the dashboard lights and attempt to start the engine (for no more than 5 seconds). If unsuccessful, gently press the rescue vehicle's accelerator to maintain around 2500 RPM, then try starting again. If the starter and fuel supply are functional, the car should start. After the dead vehicle is running, first remove the negative clamp, then the positive clamp—the same logic as in step 4 applies here. Never reverse the battery's positive and negative connections. For safety, strictly follow the order: connect positive first, then negative; remove negative first, then positive.
I've encountered several instances where my car suddenly lost power, but it doesn't necessarily mean you have to replace the battery immediately. If the battery drained because you forgot to turn off the headlights or didn't close the door tightly, you can jump-start the car with help from a friend's vehicle, and after driving for about half an hour, the battery should recharge. However, if the battery has been in use for over three years, especially if you've recently experienced frequent difficulty starting the car or noticed the headlights dimming, then it's really time for a replacement. Last time my car's battery aged, it wouldn't start after being parked for just two days, but after replacing it, I immediately noticed how much smoother the startup was. By the way, winter temperatures are particularly tough on battery condition, so it's wise to check it in advance.
My neighbor Old Zhang encountered the same issue the other day. After jump-starting, he specifically went to the repair shop to check the battery health. The mechanic said the key points are: if the battery has been used for less than two years, it's mostly due to a vehicle power leak or alternator problem; if it's been used for over four years, it's basically time for a replacement. His battery had an inspection window, and if it turned black, it indicated severe sulfation and required immediate replacement. Old Zhang's three-year-old battery, after charging, tested at only 30% capacity, so he directly replaced it with a Varta. Now it starts up with just one turn of the key.
