C43's battery died..again.
Thread Starter
Senior Member
Joined: Feb 2011
Posts: 384
Likes: 8
From: SF bay area
2012 C63 P31 LSD-Current: My past 1999 C43, 2004 Clk55, 1999 C280 sport, 1995 C280
C43's battery died..again.
Hey guys,
I got into my car this morning to go to work and the keyfob wouldn't work, opened the door manually and tried to start the car and it didn't even acknowledge the key. Im a little stumped because I have a brand new Bosch battery that is less than 3 months old. I will take the battery for testing today after work to see if it is defected by chance. Does anyone have a suggestion on what if anything may be causing a slow drain? I didn't drive it for literally one day and it died in that time frame. Thanks for any help.
I got into my car this morning to go to work and the keyfob wouldn't work, opened the door manually and tried to start the car and it didn't even acknowledge the key. Im a little stumped because I have a brand new Bosch battery that is less than 3 months old. I will take the battery for testing today after work to see if it is defected by chance. Does anyone have a suggestion on what if anything may be causing a slow drain? I didn't drive it for literally one day and it died in that time frame. Thanks for any help.
Super Member
Joined: Nov 2008
Posts: 620
Likes: 35
From: north jersey
99 c43,90 mustang gt supercharged convertible,07 acura tl type s, Hummer H3t pickup
I also purchased a Bosch battery recently..after 6 months it was spent.My car sits for months sometimes between drives so I chalked it up to that.Im on the full nothing out of pocket replacement now goin on 7 months.Purchased at Pepboys.Maybe these Bosch batteries are marginal at best.
Thread Starter
Senior Member
Joined: Feb 2011
Posts: 384
Likes: 8
From: SF bay area
2012 C63 P31 LSD-Current: My past 1999 C43, 2004 Clk55, 1999 C280 sport, 1995 C280
I also purchased a Bosch battery recently..after 6 months it was spent.My car sits for months sometimes between drives so I chalked it up to that.Im on the full nothing out of pocket replacement now goin on 7 months.Purchased at Pepboys.Maybe these Bosch batteries are marginal at best.
Ya,That could be the culprit..I did a full test at my buddies shop and everything checked out ok. Its been good since I jumped it, so I'll have to see how it goes. I did leave my charger plugged in but the light isn't on when the car is off so I figured its ok, but it could very well be the reason so I unplugged it.
MBWorld Fanatic!
Joined: Mar 2005
Posts: 2,418
Likes: 194
From: America
1999 C43 AMG, 2005 E55 Wagon
all auto batteries are made by 1 of 2 companies: johnson and exide. One of them is crap, the other is good. All other batteries are re-branded versions of these 2 batteries. Research which is which AND get yourself a solar powered trickle charger. It lays on the dash and uses the sun to gently charge your battery through the cig lighter. Keeps battery healthy for way longer if you park your car for months.
MBWorld Fanatic!
Joined: Mar 2010
Posts: 5,890
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From: Land of mountains, cheese, chocolate and watches
12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
I have used Bosch batteries for years in all my different vehicles and have never had a problem ever. 
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Joined: Apr 2014
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SLK250
Killed my 3 year old factory battery in SLK250, working on the car. Not sure what I left on ???. Charged it back up but it remained weak, so I replaced it with a NAPA 85 month AGM battery and installed a "Battery Prog Brain" which is suppose to disconnect the battery at 11.8 volts. Lead acid (AGM) batteries do not recover from zero volts very well. Time will tell how the "Battery Prog Brain" performs, so far it has not automatically disconnected the battery and the new battery is running a good 1 volt higher then the old stock battery.
