E220d (W213) stop start not working and question about Battery health

[BfgSLKMan]

SO, I have had my car now for 4.5yrs so I think that I know it quite well and I think it is now fair to say that the stop start has stopped working about 2 months ago. Yes there have been some cold days, but even after a 400km drive and my Mercedes Me App showing the starter battery as "fully charged" there has been either no start stop or literally a random stop start and then nothing for weeks now. Three weeks ago I got 3 in a row and then nothing (was only stopped at the lights about 10 secs each time).

I bought a battery health tester today and the figures for the 80Ah 800A original battery were: CCA 650, SoH 66, SoC 61 and v 12.37. Outside temp is currently about +5c and the car has been driven about 75km today. The battery is the original (week 37/18) and the car has done about 125k km.

Do these figures point to a battery problem, or a charging problem? There are no fault codes being picked up by my fault code reader?

 

[w212dcaf]

SO, I have had my car now for 4.5yrs so I think that I know it quite well and I think it is now fair to say that the stop start has stopped working about 2 months ago. Yes there have been some cold days, but even after a 400km drive and my Mercedes Me App showing the starter battery as "fully charged" there has been either no start stop or literally a random stop start and then nothing for weeks now. Three weeks ago I got 3 in a row and then nothing (was only stopped at the lights about 10 secs each time).

I bought a battery health tester today and the figures for the 80Ah 800A original battery were: CCA 650, SoH 66, SoC 61 and v 12.37. Outside temp is currently about +5c and the car has been driven about 75km today. The battery is the original (week 37/18) and the car has done about 125k km.

Do these figures point to a battery problem, or a charging problem? There are no fault codes being picked up by my fault code reader?

Did you get this resolved?

Usual suggestion to try it with the A/C off, it bypasses the need for the humidity sensor to give a 'dry' enough reading, and stop-start works more often, failing that, try heater off completely. Both of which I mean to try when the engine is warmed up. If it's still not working I'd suspect the battery.

Did the tester give a simple red/green light? I don't know much about the stats, but if SoH is state of health, then 66(%?) is not very good.

 

[BfgSLKMan]

Did you get this resolved?

Usual suggestion to try it with the A/C off, it bypasses the need for the humidity sensor to give a 'dry' enough reading, and stop-start works more often, failing that, try heater off completely. Both of which I mean to try when the engine is warmed up. If it's still not working I'd suspect the battery.

Did the tester give a simple red/green light? I don't know much about the stats, but if SoH is state of health, then 66(%?) is not very good.

Update - i put a new battery in the car and within 5 mins ss working. Even worked yesterday and it was -2.5c outside! New battery was €140 delivered. A Varta (so OE without the Mercedes sticker) was listed at €155 but not in stock. Tested the wife’s cab as her so start hasn’t been working but SoH was 92% (her battery is 3.5 yrs old). She does less miles but is hard now kicked back in after a really long drive to Bavaria last weekend.

 

[Manny729]

I will second this solution. I have 2 Mercs, both with stop start. My c220cdi (2012) started having problems with no stop start and eventually the hold facility on the brakes was not functioning. The vehicle was starting ok and battery voltage was 12.4-12.5. However, when I was away for a week and not using it, I checked on the vehicle data reading and it had dropped below that. Still starting ok but no stop start or hold function. I ordered a new F21 Varta to replace the original stamped Jun 2012 (UK Batteryforce £161) and fitted it using a small 12v battery to retain settings. What a difference? Within 200m the light was green again and the hold function had returned.

On my 2016 W246 B180cdi I have a similar fault with the green light failing to appear, sometimes only after a long journey. When this happens I charge it with my smart charger ( AGM or snow-flake setting) and the light comes on after 200m and functions properly. At 7 years old the battery efficiency is probably dropping off but the odd charge in the garage overnight every few weeks is good for now. Thankfully the Varta F21 battery fits both cars so I know the price and I have the skills to change the battery safely. I hope this post reassures others with a similar battery issue.

No matter how often I charged the c220cdi battery to “fully charged” it made no difference to stop start. It must have been past the point of no return.

If it is of interest, my c220cdi auxiliary battery was reading fine and it clearly was good after the main battery was changed. Look at the main battery first, after checking the auxiliary voltage. Don’t change the auxiliary battery hoping it will solve the problem unless the voltage after charging is down (it is AGM as well). You may end up replacing the main battery before you solve the problem and replace the perfectly good auxiliary battery.

 

[Manny729]

SO, I have had my car now for 4.5yrs so I think that I know it quite well and I think it is now fair to say that the stop start has stopped working about 2 months ago. Yes there have been some cold days, but even after a 400km drive and my Mercedes Me App showing the starter battery as "fully charged" there has been either no start stop or literally a random stop start and then nothing for weeks now. Three weeks ago I got 3 in a row and then nothing (was only stopped at the lights about 10 secs each time).

I bought a battery health tester today and the figures for the 80Ah 800A original battery were: CCA 650, SoH 66, SoC 61 and v 12.37. Outside temp is currently about +5c and the car has been driven about 75km today. The battery is the original (week 37/18) and the car has done about 125k km.

Do these figures point to a battery problem, or a charging problem? There are no fault codes being picked up by my fault code reader?

See my recent post on the subject. I tried all sorts of things but after checking auxiliary battery voltage was good I replaced main battery and all my problems went away. Green light on after 200m and brake hold function restored. My battery Varta AGM F21 was £161 From Batteryforce in UK. 12.37v is roughly the same voltage after standing for a week as my failed battery. It was much higher after charging on AGM setting but battery was clearly my problem. Hope this helps.

 

[BfgSLKMan]

See my recent post on the subject. I tried all sorts of things but after checking auxiliary battery voltage was good I replaced main battery and all my problems went away. Green light on after 200m and brake hold function restored. My battery Varta AGM F21 was £161 From Batteryforce in UK. 12.37v is roughly the same voltage after standing for a week as my failed battery. It was much higher after charging on AGM setting but battery was clearly my problem. Hope this helps.

Same with me - all sorted

 

[EdavidE]

SO, I have had my car now for 4.5yrs so I think that I know it quite well and I think it is now fair to say that the stop start has stopped working about 2 months ago. Yes there have been some cold days, but even after a 400km drive and my Mercedes Me App showing the starter battery as "fully charged" there has been either no start stop or literally a random stop start and then nothing for weeks now. Three weeks ago I got 3 in a row and then nothing (was only stopped at the lights about 10 secs each time).

I bought a battery health tester today and the figures for the 80Ah 800A original battery were: CCA 650, SoH 66, SoC 61 and v 12.37. Outside temp is currently about +5c and the car has been driven about 75km today. The battery is the original (week 37/18) and the car has done about 125k km.

Do these figures point to a battery problem, or a charging problem? There are no fault codes being picked up by my fault code reader?

I had the same problem, both batteries were always fully charged and six years old. Replaced the main starter battery with a VARTA,, Mercedes use Varta batteries anyway !!, that cured the stop/start issue, best way to keep the cars electronics live is a Memory Saver with "crocodile clips" plugged into the OBD 11 connected to a 12v battery/

 

[EdavidE]

I had the same problem, both batteries were always fully charged and six years old. Replaced the main starter battery with a VARTA,, Mercedes use Varta batteries anyway !!, that cured the stop/start issue, best way to keep the cars electronics live is a Memory Saver with "crocodile clips" plugged into the OBD 11 connected to a 12v battery/

To try and solve my original problem with the stop/start issue, When the car went in for a service I outlined the problem and I was advised the problem was the Sta