How long does our battery last????
Short trips, letting the battery run down and leaving the car exposed to temperature extremes can kill a battery in a couple of years. Just one time of letting a battery run down is enough to cut its life in half.
The way he explained it to me was that it is not the "bad" battery, but a fan that stays on for too long after car is turned off (software problem that does not shut that fan on time, which was resolved after 2010) and in time degrades the battery causing it to fail. Obviously doing a recall is too costly (since not all cars are failing), but on those that do, they replace the battery.




The way he explained it to me was that it is not the "bad" battery, but a fan that stays on for too long after car is turned off (software problem that does not shut that fan on time, which was resolved after 2010) and in time degrades the battery causing it to fail. Obviously doing a recall is too costly (since not all cars are failing), but on those that do, they replace the battery.
What fan are you talking about? I have a 2010 E550 and I have never heard any fan running if the car engine is OFF. Not even when it is very hot day and engine has run hours before I shut it OFF.
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In my case, however, the tech not only updated the software, he did me a favor and turned off the "drying" feature. Many miles and months later, the AC began to stink of manure when first started. The dealer turned the feature back on and informed me the the tech is no longer a Mercedes employee.
Last edited by Live Oak; Aug 11, 2013 at 07:19 PM.
In my case, however, the tech not only updated the software...
Can I just bring it in first thing in the morning without an appointment?
According to the PDF owners manual "It is possible that the 'residual heat' function may be activated automatically an hour after the SmartKey is removed. The vehicle is then ventilated for 30 minutes to dry the air conditioning system." Sounds like early W212 cars may have had a software glitch that let the fan run way longer than 30 minutes.
The manual doesn't make it clear so I'm guessing cars without a REST button still have the automated A/C drying feature.
12.68V = 100%
12.45V = 75%
12.24V = 50%
12.06V = 25%
11.89V = 0%
"When measuring SoC by open circuit voltage, the battery voltage must be truly 'floating' with no load present. Installed in a car, the parasitic load present makes this a closed circuit voltage (CCV) condition that will falsify the readings. Adjustments must be made when measuring SoC in the CCV state by including the load current in the calculation. In spite of the notorious inaccuracies, most SoC measurements rely on the voltage method because it’s simple."







