vtmom19

2012 E350 Cabriolet. Drive it about 6k miles a year. New battery installed by Mercedes dealer 1 1/2 years ago. Battery dead last weekend. Trickle charged it and drove back to dealer. They charged me $475 for a new battery and advised me that I need to trickle charge it often because the car is meant "to be driven". I have had 6 Mercedes over 25 years (all low mileage) - never had this problem before. Question is: is it really necessary to trickle charge this battery as the dealer advised or am I getting BS now that the warranty is over? What if I have to leave my car at the airport for two weeks???

ffr2014

2 weeks sitting shouldn't be an issue for a working battery to maintain its charge (although a sitting battery does lose charge as car continually draws for things like clock, security system, etc.). But certainly much longer periods may warrant trickle charger use.

ffr2014

Also, I have the original battery on my 2012 E550 and it has sat for 30 days with no issue starting but it rarely sits for more than a few days typically and I have never jump-started or trickle charged the battery. So I agree that continued use (i.e. trickle charging) adds to longevity of the battery.

PaulE550

I have to completely agree with ffr2014. Newer MB vehicles have a lot more electronics built into them that draw incidental amounts of power even when the vehicle is supposedly off. Same holds true for every other brand, so it's not an MB issue. The newer the vehicle, the more all the electronics options built into it draw power when the car is off. In reality, there is no such thing as the vehicle being completely off from the perspective of various electronic components drawing power.

I actually find MB quite good at being able to left for extended periods of time (3 or 4 weeks while out of town) without draining the battery below initial cranking levels. I've driven various Lexus vehicles over the last 20 years and they generally drain the battery below cranking levels after only 10 to 12 days.

Like ffr2014, I drive each of my vehicles at least a couple of times per week. It does help keep the battery in good shape and last longer.

vtmom19

Thanks very much for your comments and descriptions of your experiences. Further explanation of my experiences with my E350: Although total annual mileage is relatively low, I drive the car almost every day. I live in a small town, so most of my trips are short and stop and go. The longest it has ever sat without being driven was 17 days (once) when I was traveling. It seems, from what you both are saying, that I should not have to trickle charge the battery if I am driving it 5 or more times a week, which I am. Also, I shouldn't have to replace the battery after only 1 1/2 years. Am I correct in my understanding? Again, thanks for your help.

GerryMac

I have had an issue with my battery charging but never had to replace it. Although I drive my car almost daily, my trips are short and I was told by Mercedes Service that the battery does not get properly charged unless it is driven for 30 consecutive minutes once a week or every couple of weeks.

PaulE550

To keep your battery fully charged, you should drive the car for at least 30 to 45 minutes once or twice a week. I've seen people who drive their cars 6 or 7 days a week, but only for 5 or 6 minutes a day end up with dead batteries after 18 or 24 months. They are simply not driving the car long enough each day to ever keep the battery fully charged. So it dies prematurely. If that is how you drive, then just put a trickle charger on the car's battery over-night one night every two weeks.

beejAMG

i only drive my C63 on weekends. sometimes not even. on those days, more often than not. its hooked up to a ctek. never had any issue with the battery for almost 2 yrs now.

my advice, get one and charge you bat once a week. see if that helps.

2013E550C

I have always had a "hobby car" that was driven 1-3K miles a year. Battery
was ALWAYS an issue. Usually just hooked up a battery charger about once
a month and gave it a good charge. Also battery does not like this, and
needed to replace about ever four years.