Locating the Mercedes GL battery requires understanding the specific model year and variant, as placement has evolved significantly over the generations. Early W164 models often feature a conventional engine bay position, while later vehicles, particularly the X166 GL-Class and the newer X257 GLB, frequently house the unit in the trunk behind the rear seat. This shift towards trunk-mounted batteries is a trend across modern Mercedes-Benz vehicles, optimizing front weight distribution and utilizing underutilized space.
Identifying Your Mercedes GL Generation
Before attempting to service the battery, it is critical to confirm the generation of your Mercedes GL. The original GL-Class (W164), produced from 2006 to 2012, typically stores the battery in the front engine compartment. The second generation, known as the X166 (2013-2019), and the current third generation, the X257 (2020-Present), both utilize a rear-mounted battery located in the cargo area. For the compact GLB (X247), the battery is also situated in the rear, often on the passenger side behind the access panel.
W164 (2006-2012) Engine Bay Location
If you are driving a first-generation GL, you will find the battery exactly where you would expect it in any traditional luxury SUV. Open the hood and look on the passenger side of the engine bay. The battery is secured in a standard bracket and is usually very accessible for diagnostic checks or replacement. This front location makes it easy to inspect for corrosion on the terminals, a common issue in the saline-rich environments where road salt is used.
X166 and X257 (2013-Present) Trunk Placement
For owners of the second and third generation GL-Class models, the battery is no longer under the hood. To access it, you must open the rear hatch and look behind the plastic trim panel covering the cargo area wall. The battery is typically secured to a vertical wall on the passenger side of the vehicle. This design is part of Mercedes-Benz's strategy to improve handling by keeping the heavy component as far back as possible, which also frees up space in the front for other components.
Tools and Safety Precautions
Accessing the battery in a modern GL requires a set of basic tools, specifically a socket wrench set and a pair of safety gloves. Because these vehicles are equipped with advanced driver-assistance systems, disconnecting the battery can trigger warning lights or require a reset procedure. It is highly recommended to use a memory saver device connected to the OBD-II port before disconnecting the negative terminal. This preserves the vehicle's computer memory, preventing the need to recalibrate radio presets or adaptive cruise control settings after the replacement.
