Replacing a battery
Thread Starter
Member
Joined: Dec 2015
Posts: 110
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From: Northen California
2012 e350 bluetec
Replacing a battery
The original MB battery in my 2012 E350 BT is now going on 5 years old. I want to have it checked but if it needs replacement what's the process?
Do I need to supply a 12v charge across the + and - jumper posts to keep my settings after removing the battery?
If I do that the battery cables will then be charged and I risk shorting the electrical system during installation. Is that correct? How do you prevent that?
Any recommendations on a good battery. Mine is 800 CCA.
Do I need to supply a 12v charge across the + and - jumper posts to keep my settings after removing the battery?
If I do that the battery cables will then be charged and I risk shorting the electrical system during installation. Is that correct? How do you prevent that?
Any recommendations on a good battery. Mine is 800 CCA.
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Joined: Jan 2009
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From: V E G A S
1922 Ford Model T / no OBD
If it ain't broken - don't fix it.
Testing batteries is a whole science.
Beside new-technology gizmos you can do load test.
The easiest is display car voltage without starting the engine, then turn all the headlights and blower on. Voltage drop will give you INDICATION about battery condition.
Other test would be - when at home - start/stop the engine several times in the row.
If the battery let you crank the engine for couple of minutes -it should last for a while.
Recharge the battery after the test.
Testing batteries is a whole science.
Beside new-technology gizmos you can do load test.
The easiest is display car voltage without starting the engine, then turn all the headlights and blower on. Voltage drop will give you INDICATION about battery condition.
Other test would be - when at home - start/stop the engine several times in the row.
If the battery let you crank the engine for couple of minutes -it should last for a while.
Recharge the battery after the test.
Thread Starter
Member
Joined: Dec 2015
Posts: 110
Likes: 10
From: Northen California
2012 e350 bluetec
No offense but that seems a little too much like checking for land mines with your feet!
I think I'll have it load tested to determine the percentage of battery life remaining.
I'd rather replace it on my terms than wait for a cold, rainy night on the road somewhere. Just want to be a little more proactive.
I think I'll have it load tested to determine the percentage of battery life remaining.
I'd rather replace it on my terms than wait for a cold, rainy night on the road somewhere. Just want to be a little more proactive.
MBWorld Fanatic!
Joined: Mar 2008
Posts: 3,714
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From: 1 hours drive north of Sydney Australia
2007 W204 220CDI Classic Sedan
My original Varta 70 amp hour Absorbed Glass Mat battery will be 10 years old in October (car build date).
Yours may be only at half life.
Yours may be only at half life.
Thread Starter
Member
Joined: Dec 2015
Posts: 110
Likes: 10
From: Northen California
2012 e350 bluetec
That would be nice. The dealer wants $400-$500 to replace. Not that I'd have them do it. I'd replace it myself with an Interstate AGM for around $270 or so.
I just wanted to know how to avoid losing my settings. I don't know if those cig lighter 12v battery savers work or not. I guess it depends if the cig lighter circuit is live with the ignition switch off. I'd have to check.
I just wanted to know how to avoid losing my settings. I don't know if those cig lighter 12v battery savers work or not. I guess it depends if the cig lighter circuit is live with the ignition switch off. I'd have to check.
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Joined: Jan 2016
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
While Kaji's post made me chuckle and vow to not let him ever touch my car with his tools, he does have a good point about using the car's voltmeter to check battery condition. Get the VM showing on the dash display then turn the car to "on" to get the glows lit up. Observe the voltage. Turn the key to "start". Observe the voltage. If you're dropping into the single digits, that's bad. In my opinion. Other than that, I'd not sweat over a 5 year old battery unless I knew it had been abused (drained to zero more than once or twice).
Batteriesplus.com shows your battery (850CCA Duracell) for about $220. Easy job to change, and as far as "settings" goes it'll take about 5 minutes to restore what was there prior to swapping it out.
https://www.batteriesplus.com/batter...iesel_optional
They'll even give you 10% off if you buy it online and pick it up in the store.
Not affiliated with B+ but I have used their batteries in my trucks, cars, and motorcycles with happy endings. Got 'em in my Benz and Ducati right now.
Edit: If your ciggy lighter is fused like my '05, there's a 2 position fuse that energizes it. In one position, it is hot all the time. In the other position, it is hot only when the car is on. Your owner's manual will tell you where the fuse is, and looking at the fuse will show you if there is an A/B position.
Batteriesplus.com shows your battery (850CCA Duracell) for about $220. Easy job to change, and as far as "settings" goes it'll take about 5 minutes to restore what was there prior to swapping it out.
https://www.batteriesplus.com/batter...iesel_optional
They'll even give you 10% off if you buy it online and pick it up in the store.
Not affiliated with B+ but I have used their batteries in my trucks, cars, and motorcycles with happy endings. Got 'em in my Benz and Ducati right now.
Edit: If your ciggy lighter is fused like my '05, there's a 2 position fuse that energizes it. In one position, it is hot all the time. In the other position, it is hot only when the car is on. Your owner's manual will tell you where the fuse is, and looking at the fuse will show you if there is an A/B position.
Last edited by rapidoxidation; Apr 10, 2017 at 11:38 PM.
Thread Starter
Member
Joined: Dec 2015
Posts: 110
Likes: 10
From: Northen California
2012 e350 bluetec
Thanks for the info. I don't know if my car has the voltmeter display or not but I have a multimeter that will work. Also, my radar detector shows a voltage readout and I know the car is charging at 14.x volts so the charging system is good. I think I need a battery draw test with the proper equipment to really know if the draw capacity is there. I'm having it checked today.
Regarding settings, my main concern was losing the electrical connection during the battery install process and having the car go into limp home mode or something stupid like that.
Regarding settings, my main concern was losing the electrical connection during the battery install process and having the car go into limp home mode or something stupid like that.
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MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
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From: V E G A S
1922 Ford Model T / no OBD
Don't panic. No car will go into limp after battery disconnect.
Your model is W212 body, so go to section to check what needs to be reset.
Most likely steering sensor and windows.
Your model is W212 body, so go to section to check what needs to be reset.
Most likely steering sensor and windows.
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Thread Starter
Member
Joined: Dec 2015
Posts: 110
Likes: 10
From: Northen California
2012 e350 bluetec
Thanks. I figured that but you never know about radio lockout, etc. Some guys with other makes complain of having to go to the dealer to get things reset or have their radio codes restored.
My battery tested 9.6v at cranking with 400A load so it's at the bottom end of acceptable. The day it was tested was cold and rainy but the cranking test didn't account for temperature.
I'm OK for the time being but will replace the battery in the next month. I can keep an eye on it with my multimeter by using the min/max function. Don't need to put another load on the battery at this point. Can't complain about it lasting five years.
My battery tested 9.6v at cranking with 400A load so it's at the bottom end of acceptable. The day it was tested was cold and rainy but the cranking test didn't account for temperature.
I'm OK for the time being but will replace the battery in the next month. I can keep an eye on it with my multimeter by using the min/max function. Don't need to put another load on the battery at this point. Can't complain about it lasting five years.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
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From: V E G A S
1922 Ford Model T / no OBD
Last radio I have seen installed in MB was on 2003 model.
Newer cars have command center that is hard-coded to the car by SD and you don't loose the code.
How did you measure 400 amp?
Newer cars have command center that is hard-coded to the car by SD and you don't loose the code.
How did you measure 400 amp?
Senior Member
Joined: Apr 2006
Posts: 436
Likes: 36
From: Barrington IL
2015 E 250, 1999 BMW M Roadster, 1939 International Harvester, 2023 GLC
my battery on my 2005 E CDI was original when I sold it last summer with 225,000 miles. These monsters last a long time
Member
Joined: Nov 2011
Posts: 118
Likes: 5
From: Ohio
2006 E320 CDI
I got ten years out of my original battery. Replaced with Auto craft H8. [Advanced Auto]
Free installation and they use a settings saver via the cigarette lighter.
Couldn't be easier.
Good luck
Free installation and they use a settings saver via the cigarette lighter.
Couldn't be easier.
Good luck
