The stop-start function of the E220d (W213) is malfunctioning, and I have a query about the condition of the battery.

[MBcarOWNER]

After owning my automobile for 4.5 years, I have been familiar with it. It is now evident that the stop-start feature has ceased functioning around 2 months ago. Indeed, there have been a few chilly days. However, despite driving a distance of 400 kilometres and my Mercedes Me App indicating that the starting battery is "completely charged," the start-stop function has either not been activated or has sporadically started and stopped, and thereafter remained inactive for many weeks. Three weeks ago, I had a consecutive occurrence of three instances, followed by a subsequent absence of similar incidents. During each occurrence, my progress was momentarily halted at traffic signals for a duration of around 10 seconds.

Today, I purchased a battery health tester and obtained the following measurements for the original battery with a capacity of 80Ah and a peak current of 800A: Cold Cranking Amps (CCA) of 650, State of Health (SoH) of 66%, State of Charge (SoC) of 61%, and voltage (v) of 12.37. The present outside temperature is around +5°C, and the automobile has been driven a total distance of 75 km today. The battery is the factory-installed unit manufactured in week 37 of 2018, and the automobile has accumulated around 125,000 km.

Do these data indicate a battery issue or a charging issue? My fault code reader is not detecting any fault codes.

[JEEPWRANGLER2020]

Has this issue been resolved?

A common recommendation is to disable the air conditioning (A/C) system, since this eliminates the reliance on the humidity sensor to get a sufficiently low value. Additionally, turning off the A/C may increase the success rate of the stop-start function. If this does not resolve the issue, another proposal is to entirely deactivate the heater. I want to test both of these once the engine has reached its optimal operating temperature. If the issue persists, I would think that the battery is the cause.

Did the tester provide a straightforward indication using a red/green light? Although I lack knowledge about the statistics, if SoH refers to status of health, then a value of 66% is considered suboptimal.

[MBcarOWNER]

Update - I installed a new battery in the vehicle and after 5 minutes, it started functioning. I worked yesterday despite the temperature being -2.5°C outdoors. The cost of the newly purchased battery, including delivery, amounted to €140. A Varta battery (without the Mercedes label) was priced at €155 but was unavailable. I conducted a diagnostic test on the wife's vehicle, as she reported that the engine was not starting properly. The state of health (SoH) of the battery was determined to be 92%, despite its age of 3.5 years. She has driven less kilometres, but she is now relaxed after a lengthy trip to Bavaria last weekend.

[MercedesFan2022]

I agree with this solution. I own two Mercedes vehicles, both equipped with stop-start technology. The 2012 model of my c220cdi began experiencing issues with the lack of stop-start functionality, and finally, the hold feature on the brakes stopped working. The car exhibited satisfactory starting performance and the battery voltage measured between 12.4 and 12.5 volts. Nevertheless, after my absence of one week without using it, I inspected the car data reading and saw that it had decreased below the aforementioned level. The device is able to initiate but lacks the capability to stop, start, or maintain its operation. I purchased a brand new F21 Varta battery to substitute the initial Jun 2012 stamped battery (purchased from UK Batteryforce for £161). I installed it by use a tiny 12v battery to preserve the settings. What is the disparity? At a distance of 200 metres, the traffic signal had turned green once again and the hold function had been restored.

I am experiencing a similar issue with the green light not illuminating on my 2016 W246 B180cdi. This problem seems to occur, sometimes only after a prolonged drive. In such instances, I use my intelligent charger (set to AGM or snow-flake mode) to recharge it. After covering a distance of 200 metres, the LED illuminates and the device operates correctly. By the age of 7, the battery's efficiency is likely declining. However, charging it in the garage overnight every few weeks is now beneficial. Fortunately, the Varta F21 battery is compatible with both automobiles, allowing me to ascertain the cost and possess the necessary expertise to replace the battery securely. I trust that this content provides solace to others with a comparable battery problem.

Regardless of how often I charged the c220cdi battery to its maximum capacity, it had no impact on the stop-start function. It must have beyond the threshold beyond which there is no possibility of going back.

If you are interested, the auxiliary battery of my c220cdi was functioning well and it remained in excellent condition even after the main battery was replaced. Inspect the primary battery first, subsequent to verifying the secondary voltage. Do not replace the auxiliary battery in the expectation that it would resolve the issue, unless the voltage decreases after charging (and it is also an AGM battery). Prior to resolving the issue and replacing the fully functional auxiliary battery, it is possible that you will need to replace the primary battery.

[MercedesFan2022]

After verifying that the voltage of the auxiliary battery was satisfactory, I proceeded to replace the main battery, which successfully resolved all the issues I was experiencing. The green light turned on after a distance of 200 metres, and the brake hold function has been restored. The price of my Varta AGM F21 battery from Batteryforce in the UK was £161. The voltage of 12.37v remains relatively same after a week of standing, similar to the voltage of my malfunctioning battery. The battery's voltage significantly increased after charging on the AGM option, indicating that the battery was the root cause of the issue. Hopefully, this information proves beneficial.

[MBcarOWNER]

I have also resolved the issue.

[David_Smith2003]

I had a similar issue where both batteries consistently maintained a full charge despite being six years old. I replaced the primary starting battery with a VARTA battery, since Mercedes vehicles already use Varta batteries. A Memory Saver with "crocodile clips" linked to the OBD II port and a 12v battery is the most effective method to maintain power to the car's electronics and resolve the stop/start problem.

[David_Smith2003]

In an attempt to resolve the first issue with the stop/start problem, I brought the vehicle in for servicing and explicitly described the problem. I was informed that the issue was related to the Sta.