R230 Dual Battery On-board Electrical System

rorywquin

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An old B-Class.
Front (Starter) Battery • Function:

i) supplies electrical power for starter motor armature only
ii) provides back up power to the system circuit

Rear (Systems) Battery - Function:

i) supplies electrical power for entire vehicle (incl. the starter solenoid)
with the exception of the starter motor armature

Everything you need to know about the R230 Dual Battery System


Hi thanks fo rteh information you have posted....do you by any chance have access to the R231 equivalent...probably the same but I suspect the battery format may be AGM and maintenance free for front as well. just want to be sure for charging.....

the parallel charging procedure at the end would be very useful as well.......my user manual says to connect charge leads to teh jump start points but I don't know which setting to use on my Ctek MXS 7 (10 years old and going strong)
 
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John Laidlaw

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Rory, Whitenemesis isn’t seen on here these days- maybe Lost Kiwi will have the information you need
 

PHUNN

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SL350 September 2014 3500cc 7G Auto Iridium Silver R231
Replacement time!
Confused about batteries...
It's doubtless time for a new one because, after a LOT of reading I think mine could be the original, supplied with the car.
For those 'in the know' this is the data detail shown on the battery, which says it is 'Mercedes-Benz Original'
( 12v 74 AH 680A (EN). A 000 982 31 08). I cannot completely decipher the age stamp on the Neg. Terminal, but it appears to contain '08'.
The CTEC charger I acquired 12 months ago (many thanks for the recommendations from all forum contributors) works like a charm. The charger remains content to 'go through the motions' with the battery, but as the 'motions' are becoming rather frequent (weekly now) in order to avoid the 'Consumers unavailable' mantra, it seems prudent to retire the old battery.
But the forum mentions an AGM as being the expected original equipment on an R230.
This battery, I suspect, is not AGM. Did Merc change the specifications from AGM to Lead/Acid when the 'facelift' took place in 2008?
So should I now replace with the same (lead/acid) type?
And if so, how about getting a 'beefier' new battery, maybe with up to 100 A(mpere?) H(ours) always provided the dimensions remain the same?
Thoughts and suggestions would be gratefully received.

And even more importantly: A very Merry Christmas and an extraordinarily Happy New Year to all our happy band of pilgrims...
 

PHUNN

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SL350 September 2014 3500cc 7G Auto Iridium Silver R231
Update.
Many national battery outfits (Kwik, National and ATS) recommend the wrong size battery for the boot. Their websites all recommend a battery model with a 374mm length which will not fit.
Found this website (maybe plagerised from our forum?!) https://www.dropbox.com/s/gnyd4fcvvuq05da/R230 Dual Battery System 11-28-02.pdf?dl=0
It seems useful and certainly indicates an AGM battery is 'standard' even though that seems less 'powerful' than the (now failing) battery in my boot...
The 'date' stamp on the Negative (black) terminal is actually 1312, so maybe the battery is 6+years old.
Next!
 

Shoey

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Mercedes SL350 55 reg
Can anyone help me, the battery light with visit work shop came on today!
I’ve checked battery and it’s good
I’ve checked alternator and it’s only sending a charge to the back battery not the one under the bonnet,
I’ve checked fuse in passenger footwell f52 and it’s good,
Can anyone give me some idea please
 

Big Janner

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Can anybody recommend a quality trickle charger for the auxiliary battery ? I think my battery is on the way out and when I purchase a new one I would like to give it the best chance. This one is probably only two years old so not happy ! Overnight on a proper charger and its still charging at 5 amps in the morning. Any thoughts folks ?

cheers

Ian


Ian
May be too late, but, I use this;
https://www.roughtrax4x4.com/maypol...oK8hyFGHZ0S74geg5G_Oj0MiH7Mt4jSoaAggLEALw_wcB

Does everything I need and yes, I know, it's only £24 and that will cause some to have palpitations, but, it works.
The only down side . . . . . . This supplier is a Toyota dealer

Supplied permenant cables, just tuck up from under the carpet
Trickle charges very nicely over night . . . . Proper job.

Also on ebay;
https://www.ebay.co.uk/itm/MAYPOLE-...-d74cdadfae1c&epid=2007037079&redirect=mobile
 
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Oldcodger

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SL500/03, GLC/19, Smart EQ Fortwo/69
Useful Info thanks
When charging the Aux battery is it better to take it out of the boot or just connect up in situ?
Thanks
 

LostKiwi

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'93 500SL-32, '01 W210 Estate E240 (RIP), 02 R230 SL500, 04 Smart Roadster Coupe, 11 R350CDi
It's fine to connect in situ. Mine is always kept topped up in situ.
 

Oldcodger

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Thanks for that - I've had a look at it and it looks like I have some peculiar push on terminals which don't seem a very satisfactory way to make a contact?
At least I think that's what they are as when I tried to peel the rubber cover off the positive post the whole thing started coming off the terminal post.
I pushed it back on quickly before I wrecked anything!
Am I just being a bit overcautious or are these some kind of weird MB thing designed to cause max frustration?
:D
 

Oldcodger

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SL500/03, GLC/19, Smart EQ Fortwo/69
Mine are standard battery clamps?
Ok - I'll have another look in the daylight. Maybe just that the clamps are not tight (I just got the car)
Which could of course be why it keeps losing charge?
Thanks guys
 

Oldcodger

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Discovered an odd thing today with the Service battery

Battery is brand new AGM which still shows the dreaded 'Electrical Consumers offline' message after a few days not running.

If I turn off the ignition and immediately start up again though it shows a message to the effect of 'Electrical consumers now connected' and hey presto everything is available. I might not have the right message details here but that's the gist

Has anyone else seen this?
 

SL63 Mark

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R231 SL63 AMG
Discovered an odd thing today with the Service battery

Battery is brand new AGM which still shows the dreaded 'Electrical Consumers offline' message after a few days not running.

If I turn off the ignition and immediately start up again though it shows a message to the effect of 'Electrical consumers now connected' and hey presto everything is available. I might not have the right message details here but that's the gist

Has anyone else seen this?

What car do you have ? Year, model etc ?
 

SL63 Mark

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To test if you have a current drain, connect a meter in series between the consumer battery negative terminal and negative lead. You need the meter set to 10v DC range. Let the car go to sleep, mine reads 50mA at rest. Then pull fuses to see what is causing the drain.

Consumers message should stay on until battery charge reaches about 12.2V, IIRC. Unusual for it to go out immediately, but possible I suppose. If this is a problem, maybe give the battery a good charge, and try using a trickle charger.
 

Oldcodger

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Thanks - I'll try that.

Why would it clear by switching the ignition off/on though?
 


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