How to Replace a Car Battery?
4 Answers
Car battery replacement method: 1. Open the two fastening buttons of the thermal insulation cotton to expose the red and black insulating covers on the positive and negative terminals. Lift the insulating covers to reveal the locking nuts. 2. Use a wrench or hex socket to loosen the fastening nut on the negative terminal, then gently pry open the fastening block with a flat-head screwdriver before pulling out the negative terminal. 3. Repeat the same procedure to disconnect the positive terminal. 4. Unscrew the nut securing the battery's locking strap, release the strap, and remove the battery. When installing the new battery, simply follow the reverse sequence. Note that during reconnection, attach the positive terminal first followed by the negative terminal—the opposite order of removal—to prevent short-circuit risks and ensure safety.
Replacing a car battery isn't actually difficult, as an experienced driver I'll share some tips. First open the hood and locate the square-box shaped battery, prepare a socket wrench and a new battery of the same model. The crucial step is the power disconnection sequence: always remove the negative terminal first before the positive one - the black terminal marked with '-' is negative, don't mix them up! After loosening the mounting bracket, you can remove the old battery. During installation, be careful not to let metal tools touch both terminals simultaneously. Finally, tighten in the order of positive terminal first then negative, and you'll know it's properly secured when you hear the locking click. Always wear insulated gloves during the entire process - if electrolyte splashes on your skin, rinse immediately with baking soda solution. Don't panic if warning lights appear on the dashboard after replacement, they'll disappear after driving about two kilometers as the system self-calibrates.
Last week, I just helped my dad replace the car battery, and it wasn't as complicated as expected. When selecting the battery model, refer to the parameter label on the old battery casing. The CCA value indicates cold cranking amps—550A is sufficient for city commuting. During removal, I found the screws stuck due to oxidation, but a spray of WD-40 rust remover made them easy to loosen. After installation, remember to reset the one-touch window function, as many cars' anti-pinch feature may deactivate after power loss. For slight corrosion on the terminals, thoroughly clean them with a paste of hot water and baking soda—otherwise, even a new battery won't last long. Applying specialized grease on the terminals is recommended to slow oxidation.
There are several obvious signs of battery aging: difficulty in cold starts, dimming headlights, and failure of the start-stop function. If the measured voltage is below 12V, it's time to consider a replacement. Before DIY replacement, prepare a 10-13mm socket wrench, and keep the car doors closed throughout the process to avoid triggering the anti-theft system. If you find leakage or crystallized residue on the battery tray, neutralize and clean it with an alkaline solution, as these acidic residues can corrode the chassis. For vehicles with complex electronic systems like Mercedes-Benz or BMW, it's recommended to visit a professional shop for replacement, as power loss may cause the engine to lock, requiring a specialized decoder. Do not dispose of old batteries carelessly; repair shops often offer trade-in discounts for them.
