Where is the auxiliary battery of the Mercedes-Benz CLA220 located?
2 Answers
The auxiliary battery of the Mercedes-Benz CLA220 is located on the right side of the trunk. Function of the Mercedes auxiliary battery: Its main function is to supply power to the starter, ignition system, and in-car electrical equipment when the engine is starting or running at low speed, as the car's alternator does not generate electricity or the voltage is very low. During normal engine operation, the alternator supplies power to the in-car electrical equipment and simultaneously charges the battery. Precautions for the car auxiliary battery: It is important to note that some car owners frequently install high-power audio systems. Whether driving or idling while waiting, the audio system must not be stopped. Listening to high-power audio when the vehicle is not started places an extremely high load on the battery, causing significant damage. Additionally, many devices are often connected via the power outlet, such as GPS, dash cams, and air purifiers. These additional electrical devices inherently increase the battery's burden. Moreover, the cigarette lighter in some car models remains powered even when the engine is off. If external devices are not unplugged, they will continue to consume the battery's power, leading to battery depletion.
I found that in the Mercedes-Benz CLA220, the auxiliary battery is typically hidden under the floor of the trunk, near the left rear wheel arch. You need to open the trunk, lift the carpet or mat covering the area, and you'll see a plastic cover. After removing it, the auxiliary battery will be exposed. The auxiliary battery mainly supports the start-stop system and some low-power electronic devices—don't confuse it with the main battery. I recommend turning off the engine before inspection, disconnecting the negative terminal to prevent short circuits, and regularly measuring the voltage to ensure it's functioning properly, as it tends to fail in winter. If it's aged, it needs replacement—the operation is simple, just make sure to buy the correct model.
