Replace Battery on Mercedes-Benz GLA-Class
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Can’t start your Mercedes-Benz GLA due to a dead battery? Learn how to fix the problem by replacing the battery of your Mercedes-Benz GLA.
At a Glance
- Fits: Mercedes GLA, such as the GLA250
- Battery: H7 AGM, at least 750 cold cranking amps
- Tools: 10mm socket, 13mm ratchet wrench, terminal cleaner
- Dead battery: use the emergency key in the fob to unlock the door
- Order: negative off first, negative on last
This guide provides step-by-step instructions on replacing the battery on the Mercedes-Benz GLA models, such as GLA250.
What you will need
You will need this to replace the battery on a Mercedes-Benz GLA-Class.
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Parts
- H7 AGM Battery
- Recommended Cold Cranking Amps (CCA) of at least 750A.
- Use an AGM battery. Cars with ECO start/stop need one, and a standard battery wears out quickly in them.
Tools
- Mechanic Tool Set
- 10mm socket
- 13mm ratchet wrench
- Battery Terminal Cleaner
Procedure
- Open the hood. If the battery is dead and the vehicle doesn’t unlock, use the emergency key that is inside your keyfob to unlock the driver’s door.
Pull the red hood release below the dashboard and go to the front of the car to open the hood. Use the supporting rod to hold the hood up. - Find the battery and remove the cover. The battery is located on the driver’s side of the engine compartment. The battery is between the brake fluid and the fuse box on a Mercedes-Benz GLA. Remove the cover by pulling away from the hood release cable on the battery cover, then pull out the cover.
- Disconnect the positive and negative terminals of the battery. Use a 10mm wrench to loosen the bolt, then pull the terminals out. Disconnect the negative terminal (black) first, then the positive terminal (red) last.
- Remove the battery bracket on the front side of the battery. Use a 13mm socket with an extension to remove the bolt that secures the bracket.
This is the metal plate or battery bracket that you will remove. - Remove the battery from the vehicle. Use the handles of the battery to pull the battery out.
- Install the new battery. Put the battery on the battery tray and slide it onto the metal plate that will lock the battery in. Make sure the battery is seated properly on the battery tray.
- Reinstall the battery bracket or the metal plate holding the battery and put the 13mm nut back using a wrench or a socket.
- Clean the terminals first using a battery brush.
- Connect the positive and negative terminals. Connect positive first, negative last.
Cleaning the battery terminals using a battery brush. - Connect the positive cable to the positive battery post and the negative cable to the negative battery post. Then tighten the 10mm nuts on the terminals, put the battery cover back in, and lock it.
- Start the engine and allow it to idle. ABS and traction control lights may stay on at this point, which is normal. To reset the ABS and tracking control, turn the steering wheel to the right and the left a couple of times and drive for five minutes.
Pull the red hood release below the 
Use the supporting rod to hold the hood up.
Cleaning the battery terminals using a battery brush.
To troubleshoot any warning lights that remain on, read the fault codes with a Mercedes-Benz scanner (YOUCANIC UCAN-II Pro).
The new battery has to be registered to the car
This is the step most people skip and it costs them the battery. Mercedes tracks the age and condition of the battery and adjusts charging voltage to suit, so a car that has not been told about a replacement keeps charging a brand new battery on the worn out battery’s profile. The result is chronic undercharging, a battery that fails years early and intermittent electrical faults in the meantime. Registration takes seconds with a tool that supports it, such as the YOUCANIC UCAN-II Pro, which handles battery registration on Mercedes along with the fault code reading you will want afterwards.
Fit the same type, not just the same size
If your GLA has engine stop start, it needs an AGM battery. Fitting an ordinary flooded battery works for a few months and then fails, because the standard type cannot cope with the repeated deep cycling stop start demands. Registering the wrong type is also a problem, since the charging strategy for AGM and flooded batteries differs. Check what came out before buying what goes in.
Negative off first, positive on last
Disconnect the negative terminal before the positive and reconnect it last. With the negative still attached, a wrench that slips off the positive post onto any metal part of the car creates a direct short to the battery, which produces a shower of sparks and can weld the tool in place. Done in the right order there is no return path and it cannot happen.
Expect a few things to need resetting
Losing power resets the clock, radio presets and often the one touch window function, which you restore by holding each window switch fully up and then fully down for a few seconds. Some warning lights may stay on for the first drive while modules relearn. If any remain after that, they are worth reading rather than ignoring, because a deeply discharged battery frequently leaves stored faults behind in several modules.
Frequently Asked Questions
What battery does a Mercedes GLA250 use?
An H7 AGM battery with at least 750 cold cranking amps. Match the size and type of your original battery.
Do I need an AGM battery in my GLA?
Yes, if your GLA has ECO start/stop, which most do. AGM batteries are built for the frequent restarts.
Why does my GLA show warnings after a battery change?
Low voltage and the disconnect can leave stored messages. Drive the car for a few minutes; most clear on their own. Reset the windows if one touch stops working.
