Battery seems to not hold charge, had car checked at Mercedes dealer, on 2010 Mercedes-Benz S550

They said I needed to drive car at least 20 miles a day to keep battery charged Is that true. I can the car one day and the next it will not start.

2 answers 2 comments
I agree with pushrod,that's a load of you know what! sounds like someone does not want to take the time to do a battery draw test. Usually a time consuming deal but must be done with concerns like this,and for customer satisfaction! something is draining the battery and with all of the electronics and switches in the vehicle it can sometimes take days to find an intermittent fault,but if your battery is dying all the time and it tests good...needs a battery draw test, which under warranty doesn't pay squat. 1+1=2
How can you tell if they have actually done a battery draw test? I have had the same battery problem in my 2012 S550 and they say I must have left the ignition button in not full off mode or something but sounds crazy to me. What could be drawing down the battery when it appears the car is off? I push it in to turn the car off like yow previous MB's and they had no problem. Thanks
I have an 2012 S550 with a dead battery after 8 days. Charged it up and all good but frustrating. The manual refers several times to fully powering down the display by pressing the 'ON/OFF button' several times. I also read on page 480: "Remove the SmartKey if you park the vehicle and do not require any electrical
consumers. The vehicle will then use very little energy, thus conserving battery
power." I don't know if that means pull out the 'ON/OFF button'? The car is obviously live since it has to sense the key in your pocket. Anyone know?
No other maker of automobiles has this problem, not even the cheaper ones! Ask the "Mercedes Benz" dealer to explain that to you! Sounds like a bunch BS to me. You most likely have a battery problem, is it the original battery? If so it's bout 4 years old now and may need replacing. Possible 'excessive' parasitic load on the battery also. Did the dealer check these things along with the charging system? Oh, i know about the many gadgets it has that may drain a battery, but not that quick. Dont let them get by with that explanation! Tell them to fix your car.