C117
2014 - 2019 model yearsThe first CLA45. The 2015 CLA owner's manual explains the Auxiliary Battery Malfunction message as the auxiliary battery for the automatic transmission no longer being charged.
Mercedes-AMG - CLAMercedes CLA45 Battery Replacement, Main and Auxiliary
We replace both batteries on the Mercedes-AMG CLA45 at your home, office or the roadside. Besides the main 12V battery the car carries an auxiliary battery that the CLA manuals tie to the automatic transmission, and it has its own warning on the display. Our technician tests the two separately and fits only the one that has failed.
- 10+Years on Dubai's roads
- 10,000+Customers
- 20+Mobile vans
- 4.3Google rating
Mercedes CLA45 by Generation
Two CLA45 generations, both with a second battery behind the main one. The years decide which manual and which layout apply.
C118
2019 - 2025The CLA 45 4MATIC+ ran to 2023 and the CLA 45 S to 2025. Mercedes' rescue sheets for both show one 12V AGM under the bonnet, another down in the cabin floor area, and no 48V battery.
The offer
What you get when you call
- From AED 175, fitted free
- Technician with you in about 25 minutes
- 1 year warranty
- Free battery test
- No call-out fee
- Price agreed on the phone first
From your call to a new battery in four steps
Get in touch
Call or WhatsApp with your location and car.
Hear the price
Get the price before anyone sets off.
We come to you
A technician arrives in about 25 minutes.
Tested and fitted
Free test, new battery fitted, old one recycled.
At a glance
The CLA45 Battery Pair at a Glance
Two 12V batteries with different jobs, and different signs when they weaken.
| Item | Main battery | Auxiliary battery |
|---|---|---|
| Job | Starting the car | Supporting the automatic transmission |
| Warning when it weakens | Slow or failed start | Auxiliary Battery Malfunction |
| Until it is replaced | A jump at the engine-bay connection point | P selected by hand, parking brake on |
| Our test | Under load, then the charging voltage | On its own, separate from the main battery |
From the 2015 and 2022 CLA owner's manuals and Mercedes' C118 CLA 45 rescue sheets.
The Auxiliary Battery Message on a CLA45
When the display shows Auxiliary Battery Malfunction, the CLA manuals explain it plainly: the auxiliary battery for the automatic transmission is no longer being charged. The car usually still starts, which is why owners often keep driving and assume the main battery is to blame.
While the warning stays on, Mercedes tells the driver to engage P manually at every stop and to use the electric parking brake whenever the car is left. Our technician tests the auxiliary battery on its own, then the main AGM and the charging voltage, so the right battery is replaced on the first visit.
Stuck with a flat battery right now
Open 24/7 across Dubai. The price is agreed on the phone first.
Our CLA45 Visit, Battery by Battery
Both 12V batteries checked, and only the one that has failed is replaced.
- Main AGM Under the BonnetLoad-tested in the engine bay. If it is healthy, it stays, however old the car is.
- Second AGM in the CabinReached low at the front of the cabin and measured by itself, apart from the engine-bay AGM.
- Parked Safely FirstA CLA with no battery connected stays held in P, so the car is positioned where it needs to be before the terminals come off.
- AGM to AGMThe replacement matches the AGM that came out, as the rescue sheets list for the C118 CLA45, fitted with its vent hose and terminal covers.
Mercedes CLA45 Battery Questions
The CLA owner's manuals explain it as the auxiliary battery for the automatic transmission no longer being charged. It is a separate battery from the one that starts the car, which is why a CLA45 can show the message and still start normally. We test it on its own before recommending anything.
Mercedes wants the fault looked at by a workshop. Until that happens, put the selector in P yourself every time you switch off, and set the electric parking brake before walking away. Our technician comes to where the car is parked, so there is no need to drive it anywhere with the warning showing.
Two. On the C118 CLA 45 and CLA 45 S, Mercedes draws one 12V AGM under the bonnet and the other beneath the front of the cabin, near the seats. The first-generation CLA45 also carries a main and an auxiliary battery, as its owner's manual shows.
No. When Mercedes made the petrol CLAs mild hybrids in 2023, the 48V system went to the regular models and the CLA 35, and the rescue sheets for the CLA 45 and CLA 45 S show 12V batteries only. That keeps a CLA45 battery job to the two AGMs.
According to the 2015 CLA owner's manual, disconnecting the battery leaves the automatic gearbox held in P so the car cannot roll. It stays locked until power is restored, so on a CLA45 the new battery is fitted where the car stands rather than after pushing it somewhere easier.
From AED 175 fitted, and the price for your CLA45 is agreed on the phone once we know which of the two batteries has failed. The test costs nothing, there is no call-out fee, and the battery we fit is covered by our 1-year warranty.
Not Your Model?
We fit batteries across the whole Mercedes-Benz range, and the marque page lists every model we cover.
Have Both CLA45 Batteries Tested Where It Stands
Battery Change Dubai checks the main and auxiliary batteries on your CLA45 at home, at work or on the road, and swaps only the battery the test condemns. Phone or WhatsApp whenever the warning appears.
- Both batteries tested
- Fitted where it is parked
- Old unit recycled
Service Areas
We Cover All Of Dubai
More than 20 mobile vans work across Dubai. For a battery call, a technician reaches you in about 25 minutes. The vans cover Al Karama, Dubai South, Business Bay, Downtown Dubai, office car parks, villa communities and highways.
- Al Barsha
- Jumeirah
- JBR
- Marina
- Downtown
- Business Bay
- Dubai Silicon Oasis
- DIP
- Sports City
- Studio City
- Motor City
- Arabian Ranches
- JLT
- Discovery Gardens
- Springs 7
- Mirdif
- Al Furjan
- Palm Jumeirah
- Al Sufouh
- Global Village
- JAV
- Arjan
- Barsha Heights
- Emirates Hills
- The Lakes
- Silicon Oasis
- Bur Dubai
- Meydan
- Majan
- Al Wasl
- Sobha
- Al Karama
- Dubai South
- Abu Hail