Advise, please - charging dead battery on CL600

Swotty

MB Enthusiast
SUPPORTER
Joined
Jul 25, 2014
Messages
1,691
Location
South West France
Car
2003 CL600
Hi everyone,

2003 Merc CL600 Biturbo

I left it too long and the battery is really drained - not even the lights come on. Car won't unlock except with the metal key bit.

I have a booster pack putting out 900 cranking amps and a Jag V8 with a good 100ah battery to jump start it with, if I have to.

I also have a CTEK trickle charger connected to the Jag and a 4 amp standard battery charger.

I was going to simply connect the booster, but a friend who has a modern SL said not to as it could fry some of the electrics. A quick internet search kind of confirmed this, but talked about jump start points in the engine bay.

What is the forum's advice, please? The booster is the easy way and the jump start from the Jag the next easiest, but is that going to cause electrical issues?

Many thanks for any advice.

Stuart
 

Ted

MB Enthusiast
Joined
Feb 26, 2004
Messages
5,859
Location
Bourton on Dunsmore
Car
SLC 250D AMG Line, Yamaha XVS 1100, Jeep Renegade
Put the trickle charger on overnight.
Start it and take it for a run.
If you feel like it, put the trickle charger back on until next time you want to take it out.
Be aware that if the battery is REALLY flat, the trickle charger may not start. There is a workaround for that - let us know how it goes.
 

whitenemesis

MB Club Veteran
SUPPORTER
Joined
May 7, 2007
Messages
17,208
Car
Lexus RC300h F-Sport 2019
Your handbook specifically states not to use a booster or battery quick charger. Only jump start from a 12v battery of the same as fitted to the car.

As above the safest option is to connect the trickle charger and leave overnight
 

Chrishazle

MB Enthusiast
Joined
Nov 13, 2008
Messages
3,948
Location
Nr Ashford, Kent
Car
2008 S204 C220CDI Elegance Estate Auto, 2008 R171 facelift SLK280 Auto.
If it's anything like my previous S203, there's a danger of frying the SAM's with a high voltage spike while attempting to jump start, so I'd certainly go along with the "be patient" method, the CTEK for 12-24 hours to see if that gets some power into the battery, then maybe the 4amp charger for another while. Maybe then connect the Jag battery (with the Jag engine switched off) for a while before starting the jag engine and trying to start the CL.

Sounds like you need another CTEK for the MB!!

If you're also registered on MBOA, ask on there, Television will know what's best!
 

grober

MB Master
Joined
Jun 22, 2003
Messages
28,444
Location
Perth, Scotland
Car
W204 C200CDI Estate
If the battery is more than 3 years old buy a new one--- and then look after it with a good trickle charger like a Ctek. With today's electronic laden models battery health is on a par with regular engine oil changes in terms of vehicle maintenance
 
OP
OP
S

Swotty

MB Enthusiast
SUPPORTER
Joined
Jul 25, 2014
Messages
1,691
Location
South West France
Car
2003 CL600
Thanks everyone ........ will do as you advise and put the CTEK on overnight and have a look tomorrow morning.

The Jag is on a CTEK as there is a well-known quiescent (have I spelt that right?) drain, so 2 weeks stood always equals battery too flat to start but this is the first time for the Merc.

I'm wondering if I forgot to lock it properly and it just kept recycling?

Anyway, once restarted, will have the battery checked out.

Thanks once again for the swift responses.

Stuart
 

190

MB Enthusiast
Joined
Mar 4, 2015
Messages
3,319
Location
Cheshire
Car
2009 W204 C180K
The only thing I'd add is a trickle charger will take several days to fully charge the battery. Even a 4 Amp charger wouldn't do it overnight. It may well start after a shorter period but the battery could still be a long way from fully charged. Even if you then go for a drive it could take several more hours to fully charge the battery.

How ever you do it make sure the battery gets fully charged or what remains of it's life will be compromised.
 
OP
OP
S

Swotty

MB Enthusiast
SUPPORTER
Joined
Jul 25, 2014
Messages
1,691
Location
South West France
Car
2003 CL600
Thanks, 190 ........ the trickle charger (only 800 mA) is on and showing 10.4 v ...... but it's getting very warm. Dash and boot lights on and car opens on the remote.

I'll have a look before bedtime and may take the battery off and charge up with the mains charger.

It's just the thought of having to reset everything again which deters me taking off the battery!

Thanks again,

Stuart
 

190

MB Enthusiast
Joined
Mar 4, 2015
Messages
3,319
Location
Cheshire
Car
2009 W204 C180K
At 800ma a trickle charger could take up to 6 days to charge a 100 AH battery so you may want to use the mains charger but why do you have to take off the battery to charge it. Is it an unregulated charger ? To safely charge the battery in the car the important criteria is that the charge voltage at the battery terminals shouldn't exceed 14.6 volts.
 
OP
OP
S

Swotty

MB Enthusiast
SUPPORTER
Joined
Jul 25, 2014
Messages
1,691
Location
South West France
Car
2003 CL600
Sorry to come back so late.

Well, the trickle charger got it up to 12.7 volts the next morning and it started. Took it for a shortish run and it was dead the following morning at around 10 volts.

Charged it up again and it's losing up to 2 volts overnight so have ordered a new one. Varta Silver Dynamic H3 ........ slightly bigger than I needed but it's interchangeable with the XK ........ which is advised 100ah in view of the folding roof to power.

Thanks again to everyone for your help ........ at least I now know NOT to use the battery booster on it! :thumb:

Cheers,

Stuart
 

Chrishazle

MB Enthusiast
Joined
Nov 13, 2008
Messages
3,948
Location
Nr Ashford, Kent
Car
2008 S204 C220CDI Elegance Estate Auto, 2008 R171 facelift SLK280 Auto.
Do you have some kind of current drain causing the battery to loose power overnight? Maybe a glovebox light not turning off properly?

Hope you also got a second battery conditioner so it's not just the XK getting pampered!
 

Flyinspanner

MB Enthusiast
Joined
Oct 1, 2015
Messages
1,661
Location
Ruislip
Car
W215 CL500, W168 A-140. A209 CLK conv
If you are only getting 10v, the battery has a dead cell, and is scrap.
Get a new one like a Bosch S4 or S5.

Maybe get another ctek or at least swap it over regularly so they don't get so flat in future. The cteks are good as they keep the battery well conditioned.
 
OP
OP
S

Swotty

MB Enthusiast
SUPPORTER
Joined
Jul 25, 2014
Messages
1,691
Location
South West France
Car
2003 CL600
Thanks - have already ordered the Varta replacement but am putting the savings towards another trickle charger.

Yes, reckon it's kaput as it won't hold charge. everything is off ..... interior lights/boot light etc.

Thanks again,

Stuart
 

DSB SL AMG

MB Enthusiast
Joined
Jan 28, 2010
Messages
1,598
Location
Cheshire
Car
300SL (R129 1992 pre-facelift), Volvo V70 SE D5 Auto Geartronic
Varta Silver is a great battery, hope you got a good buy as price can vary a lot on the net...they supply many global OEM's at plant.

If storing a car for a long period of time and you don't want to trickle charge, disconnect the battery negative terminal...do NOT leave connected...you can then reconnect and trickle charge a few days before start up...I learnt this lesson a few years ago as I also destroyed a good battery in the same way, luckily for me it was still under warranty so got a free replacement...
 
OP
OP
S

Swotty

MB Enthusiast
SUPPORTER
Joined
Jul 25, 2014
Messages
1,691
Location
South West France
Car
2003 CL600
Thanks - useful tip!

I paid €123 for the Varta - £103 at today's exchange rates - damn Brexit!

That's not a bad price for France ....... I paid around €200 for one for the Jag a couple of years ago - the same spec battery.

Batterie megastore ....... they have a UK arm, too.

Thanks again,

Stuart
 

DSB SL AMG

MB Enthusiast
Joined
Jan 28, 2010
Messages
1,598
Location
Cheshire
Car
300SL (R129 1992 pre-facelift), Volvo V70 SE D5 Auto Geartronic
Yep, crap exchange rate at the mo:(...same battery UK delivery £81:crazy:

Varta Silver Dynamic H3 Car Battery



Thanks - useful tip!

I paid €123 for the Varta - £103 at today's exchange rates - damn Brexit!

That's not a bad price for France ....... I paid around €200 for one for the Jag a couple of years ago - the same spec battery.

Batterie megastore ....... they have a UK arm, too.

Thanks again,

Stuart
 
OP
OP
S

Swotty

MB Enthusiast
SUPPORTER
Joined
Jul 25, 2014
Messages
1,691
Location
South West France
Car
2003 CL600
Yep - sadly can't get international delivery for batteries.

There are considerations, though ..... hourly rate for Merc garage is £83 per hour (but it was £77, pre-Brexit).

I'll have to console myself with the 33C temperature!:bannana:

Stuart
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top Bottom