C200Merc2012

The Battery sign suddenly came up on my dash while i was driving, i immediately switched of Air-con, drove further for a while then the car brake acted funny when i stepped on it, so i switched off Stereo and it went back to normal, Drove home, Switched off the Engine and Opened the Bonnet, Checked the Battery connection, Closed the bonnet and then switched on the Engine again, to my surprise the Red Battery Sign on the dash has disappeared. So I'm literally confused at the moment.

C200Merc2012

Any idea guys?

superangrypenguin

Check your alternator output. The battery light, AFAIK, comes on when there's an issue with the charging system and usually doesn't indicate a battery issue.

That said, it's now a 5 year old battery in the car, maybe even a 6 year old battery. Depending on climate and how you drive the car (parked a lot of used a lot), you MAY need a new battery, but I'd start by checking alternator output first.

Welcome to the forum!

Hariandja

I have a similar issue:
Mine is MB C200 W204 Year 2012 (engine M271)
I turned on the fancy feature to monitor the Voltage and Current on the dashboard.
All the lights, AC, radio are turned off.
- Initial battery voltage: 12.3V (I use new AMARON battery in July 2020)
- A while after starting the engine, the voltage drop to 11.5 V ( I think this is normal)
- Afterward, the voltage increase and reach 14.1V (current above 0)
- I start to turn on the radio, AC, and finally lights, the voltage still showing 13.6-13.9 V (current above zero)
- Shift the automatic tranmission lever from P to R, the voltage drop to 13 V (current drop to below zero around -2A)
- Shift again the automatic transmission lever from R to N, the voltage increase to 13.6-13.9V (the current back above zero)
- Shift again the automatic transmission lever from N to D, the voltage drop again to 12.3-12.4V (the current drop and fluctuate between +1 to -20 A)
After driving the car for about five minutes, the red engine warning light flashing and later car stall
After turn off everything, I ignite again and the engine is OK.
But the car will stall again after driving a while (like 5 minutes).

Do I need to replace the alternator for sure?
Thank you

Hariandja

Can someone please help me on my case? Thank you very much

Hariandja

this today measurement:
Mine is MB C200 W204 Year 2012 (engine M271)
I turned on the fancy feature to monitor the Voltage and Current on the dashboard:
- Initial battery voltage: 12.4V (I use new AMARON battery in July 2020)
- A while after starting the engine, the voltage drop to 11.1 V for ver short time( I think this is normal)
- Afterward, the voltage increase and reach 14.8V (current 19 A)
- I start to turn on the radio, AC, and finally all lights, the voltage drop to 13.1 V (current drop to 3A)
- Shift the automatic tranmission lever from P to R, the voltage drop to 12.8 V (current drop to -5.5A)
- Shift again the automatic transmission lever from R to N, the voltage increase to 13.V (the current going up to 9A)
- Shift again the automatic transmission lever from N to D, the voltage showing 13 V (the current drop to 2A)
- Shift back again the automatic transmission lever from D to P, the voltage showing 13.6 V (the current drop to 10A)

After driving the car for about five minutes, the red engine warning light flashing and later car stall
After turn off everything, I ignite again and the engine is OK.
But the car will stall again after driving a while (like 5 minutes).

Do I need to replace the alternator for sure?
Thank you0