R230 Consumer Battery - How To Charge

[Blaze_One]

Good evening gentlemen,

I trust one & all are well and had an enjoyable Christmas??

Have searched the forum/previous posts regarding the above and have found many posts on the subject....as an owner of a 2003 SL350 for many a moon now, I've seen the electric consumers offline message more times then I care to remember....

HOWEVER, I got back in the car today after 3.5months of not using it (!! - I have a young family now so my daily/weekend drive is now a 2013 ML) and as expected electric consumers offline message appeared (along with ESP not working - cpl of turns of the steering wheel took care of that) - the front battery was charged prior to me getting back in the car using a CTEK MXS 5.0 test & charge charger (kindly lent to me by my neighbour) so car started without any fuss (barring the two points raised above)....HOWEVER, after driving the car for over an hour & half and clocking up c.75miles the electric consumers offline message won't go off.

Now I suspect one of four things have happened - with the car sat idle for 3.5months:
a) the rear battery has died on me!
b) the rear battery may need more of a drive to get it fully charged
c) the rear battery needs more of a boost - ie from a charger
d) none of the above...lol!!!

Luckily, my neighbour is happy to lend me his CTEK MXS 5.0 test & charge charger - see link... ( http://www.ctek.com/gb/en/chargers/MXS 5.0 TEST AND CHARGE )

Before potentially purchasing a new battery I'd be keen to see if I can get a charge back into the current one. Therefore, could I kindly ask the following:

1) Am I correct in assuming the battery is of an AGM variety (the CTEK charger states it can charge these types of batteries) - what's the difference between that and the battery at the front of the car?

2) Can I fully disconnect the consumer battery from the rear and effectively charge it standalone using the charger OR on putting back in, will I need to connect the car up to STAR to reconfigure and/or will I get fault warnings

3) If charging in-situ - is it as simple as connecting the charger up overnight (or however long it needs to be)

4) If charged in-situ - the CTEK charger has a RECONDITION option/mode which does what it says on the tin - however, I understand that it "provides a 15.8v topping-charge at reduced current for a limited time to promote controlled gassing/forced mixing of the acid within the battery" - does anyone know if 1) that would damage the AGM battery and/or 2) possibly damage any of the electronics in the car as it would be sending a bigger charge through the battery - this option CAN be omitted but thought it may be worth doing if it helps recondition the battery

Any help you could provide on the points above would be gratefully received...

Thank you in advance...

Best wishes
H

 

[television]

You really do need a check test on the main battery, its quite possible the rear starter is all starting it up all from the starter battery. I would estimate that the rear battery is useless at all.

 

[nicholas15]

Having just acquired a 2003 SL500 I have also been having battery problems, linked possibly with its lack of use (300 miles last 12 months, 1200 miles previous 12 months).
Briefly, AA had fitted wrong battery (twice) in boot - apparently it needs to be the starter battery strength rather than the consumers strength battery. Local MB dealer fiteed starter battery in boot (£250 + VAT including check/fitting and battery at £150). Details under "What have you done to your Mercedes" thread.

I read somewhere that you might need up to 50 hours to recharge heavily discharged starter battery; also that CTEK charger may not be effective if deeply discharged but use a heavy duty charger to bring it up to a level where the CTEK will then work.

But then I have been confused somewhat so others may offer better advice!

 

[EmilysDad]

..... Local MB dealer fiteed starter battery in boot (£250 + VAT including check/fitting and battery at £150). .....

****** Hell!!! MB certainly know how to charge! (presumably an hour's labour )

 

[Blaze_One]

You really do need a check test on the main battery, its quite possible the rear starter is all starting it up all from the starter battery. I would estimate that the rear battery is useless at all.

Hi Malcolm,

I trust all is well?

Checked the front battery after charge & also this evening and it seems to be fine - holding the charge fine. Having sat idle for 3.5mths, initial reading prior to charging was 11.9 - post charge it was 13.6/7 and having checked again tonight it is sitting comfortably just under 13. I'll check the front battery again in the morning after the car has sat idle for c.10/12 hrs

 

[television]

Once again the 230 will always start from the front up battery, if the battery in the rear has now voltage at all, it cannot aid at all to aid with any aid.


You do to need to check the actual voltage over that rear battery, while is so low, the car is probably using the 57 relay to start the car up.

 

[television]

Hi Malcolm,

I trust all is well?

Checked the front battery after charge & also this evening and it seems to be fine - holding the charge fine. Having sat idle for 3.5mths, initial reading prior to charging was 11.9 - post charge it was 13.6/7 and having checked again tonight it is sitting comfortably just under 13. I'll check the front battery again in the morning after the car has sat idle for c.10/12 hrs

The starter battery can stay up for all charge, it is the voltage over the rear battery that you do must check before anything any thing else.

 

[Blaze_One]

Sorry Malcolm, I misread your post - apologies...so basically,

So I haven't checked the voltage on the rear battery at all (doh!) - so having read one of your previous posts - the rear battery "should be 12.5 engine off and at least 13.8 with the engine running"... if it's not either of these, should I assume life is over for the battery or worth me trying a charge then checking/taking readings an hour after use??

Sorry for my ignorance, but I'm not sure what the 57 relay is? Could you shed any light.

Many thanks.
H

 

[television]

I would say that the rear battery is just so bad that it is doing nothing at all.


The front battery cannot drain at all on the 230 at all.


The battery can only run for 2½ weeks with no charge for the rear battery.

 

[Blaze_One]

[/quote] I read somewhere that you might need up to 50 hours to recharge heavily discharged starter battery; also that CTEK charger may not be effective if deeply discharged but use a heavy duty charger to bring it up to a level where the CTEK will then work.

But then I have been confused somewhat so others may offer better advice![/QUOTE]

My understanding is that the CTEK will work on voltages as low as 2.0V (tech spec. from CTEK's website) which I understand is very low...but I'm not expert!

 

[Blaze_One]

I would say that the rear battery is just so bad that it is doing nothing at all.


The front battery cannot drain at all on the 230 at all.


The battery can only run for 2½ weeks with no charge for the rear battery.

So if I replace the battery, will I need to have it connected to STAR afterwards to configure it/prevent any fault codes or is it as simple as "plug & play" (I suspect I already know the answer to this...lol!!)

 

[television]

You cannot charge the rear battery at all from joining up to the front battery, it needs to have a voltage after charging of more that 11.75, that is the point where all consumers shutting off, I do doubt with now much that any any use left, you must be, but that can take a very long time to try and.

 

[alexanderfoti]

If your rear battery has not reached a voltage level that the ctek will accept after 75 miles, its most likely junk. If you can, check it with a multimeter, but I suspect that Malcolm is right.

 

[John Laidlaw]

I think we need the voltage from the rear battery, but suspect it's goosed !
MB Grangemouth recently offered me a genuine Mercedes utility battery for I think around £99
Edit: sorry just seen Alex and Malcolm both replied pretty much the same as I slowly typed !!

 

[nicholas15]

****** Hell!!! MB certainly know how to charge! (presumably an hour's labour )

£90 per hour for cars over 7 years old versus £130 per hour for newer models. This was charged at old car rate!

 

[Blaze_One]

If your rear battery has not reached a voltage level that the ctek will accept after 75 miles, its most likely junk. If you can, check it with a multimeter, but I suspect that Malcolm is right.

Hi Alexander - thank you for your post - however, I've yet to connect the rear battery to the CTEK - it is only the front battery I've charged to date...

I was keen to find out when charging the rear battery if:

1) Can I fully disconnect the consumer battery from the rear and effectively charge it standalone using the charger OR on putting back in, will I need to connect the car up to STAR to reconfigure and/or will I get fault warnings

2) If charging in-situ - is it as simple as connecting the charger up overnight (or however long it needs to be)

4) If charged in-situ - the CTEK charger has a RECONDITION option/mode which does what it says on the tin - however, I understand that it "provides a 15.8v topping-charge at reduced current for a limited time to promote controlled gassing/forced mixing of the acid within the battery" - does anyone know if 1) that would damage the AGM battery and/or 2) possibly damage any of the electronics in the car as it would be sending a bigger charge through the battery - this option CAN be omitted but thought it may be worth doing if it helps recondition the battery

 

[Blaze_One]

You cannot charge the rear battery at all from joining up to the front battery, it needs to have a voltage after charging of more that 11.75, that is the point where all consumers shutting off, I do doubt with now much that any any use left, you must be, but that can take a very long time to try and.

Thanks Malcolm - I was fairly sure that the front doesn't charge up the rear but thank you for confirming - so do you not think it a worthwhile exercise even trying to charge the rear battery and seeing if it holds above 11.75? If it does - I could be in luck?? But if not, then clearly a new battery for me

Can anyone advise if a new rear battery for the R230 is a straight swap or will I need STAR once a new battery is connected?

Many thanks.

 

[alexanderfoti]

Hi Alexander - thank you for your post - however, I've yet to connect the rear battery to the CTEK - it is only the front battery I've charged to date...

I was keen to find out when charging the rear battery if:

1) Can I fully disconnect the consumer battery from the rear and effectively charge it standalone using the charger OR on putting back in, will I need to connect the car up to STAR to reconfigure and/or will I get fault warnings

2) If charging in-situ - is it as simple as connecting the charger up overnight (or however long it needs to be)

4) If charged in-situ - the CTEK charger has a RECONDITION option/mode which does what it says on the tin - however, I understand that it "provides a 15.8v topping-charge at reduced current for a limited time to promote controlled gassing/forced mixing of the acid within the battery" - does anyone know if 1) that would damage the AGM battery and/or 2) possibly damage any of the electronics in the car as it would be sending a bigger charge through the battery - this option CAN be omitted but thought it may be worth doing if it helps recondition the battery

Aha
1. You can remove and charge separately with no ill effects.
2. Yes
4. You can safely use the recondition option on your battery.

What happened to 3?

 

[Blaze_One]

I think we need the voltage from the rear battery, but suspect it's goosed !
MB Grangemouth recently offered me a genuine Mercedes utility battery for I think around £99
Edit: sorry just seen Alex and Malcolm both replied pretty much the same as I slowly typed !!

Thanks John - too late in the day now, but will get a multi meter on it in the morning but suspect I now the outcome following Malcolm's post :cry:

This is the exact reason why I decided to start the car AFTER Christmas - if I'd done it before would've ruined the day for me...lol!!

 

[Blaze_One]

Aha
1. You can remove and charge separately with no ill effects.
2. Yes
4. You can safely use the recondition option on your battery.

What happened to 3?

1. - That's good to hear - I was always under the impression that if you remove the consumer battery you had to get it back on STAR as error codes would come up - also means that I don't have to leave the boot open on the car all night whilst charging (note to self - clean out garage!!!)

2. Excellent

3. :!:

4. Would the recondition option work on a AGM battery? And if charged with the consumer battery in the car - no electricals would be fried?? (My neighbour has already said he won't take any responsibility if it does...lol!!)

Could I ask Alex, have you used a CTEK MXS 5.0 yourself on the consumer battery? Or know/experience of someone who has?

Thank you for taking the time to come back to me.

Regards
H