SL500 Convenience battery

[blak500]

H guys I have a question about the convenience battery in a 2003 SL500, I broke my ankle about 10 weeks ago, so the caronly got driven for about 20mins to 30mins every week for the lst 10 weeks, i am back driving the car myself now, but the dash always says electric consumers offline, and it take 12-15 mins to charge up. However as soon as i turn the ignition off even after a long drive,( I have been driving the car at least an hour a day now for the last 5 days), the electric consumers are off line again. Does this mean I need to get a new battery? and if so where can I get one from and how much will it cost and can I fit it myself!? Thanks a lot guys for your help!! I cant believe how much I missed driving!!:bannana::bannana:

 

[richard]

My 04 SL needed a new battery at about 4.5 years - exactly this fault, and so did my friend's 03 SL at 4 years - so you've done better than me or him ! (Neither of us do many long journeys, and cars not used that much, so a bit harder on the batteries)

Battery is in the boot, you need a 13mm long socket set to release the battery and a 10mm spanner to undo the battery terminals. Undo & remove the ground one first. Dont forget to connect the emergency-acid-overflow tube back up again. Re-connect & tighten the live first. Expect a spark when you connect the ground back up.

Most battery shops will fit this for you. Personally I always put a Mercedes battery back in again, because on a 4 year old car you can argue for a 20% discount on parts at many MB dealers, and it has a 2 year warranty on it

Richard

 

[Matt45]

I had similar probs and thought I had a drain on the battery in my 04 SL. MB swapped the battery but it also was poor so I got a third and now everything is OK. I would get a MB one from your nearest dealer; I bet they're not much more than Halfords and you know you're getting the right thing with a warranty. The consumers warning will come on when the battery falls below 11.5 volts. I bought a charger and every month I put it on low charge for a couple of hours just to keep the battery in tip top condition. I also switched off the locator lighting option which was causing a 'light sensor' warning on the dash at the same time. For the last 12 months it's been fine [fingers crossed]. Operating the roof and seats with the engine not running is a real killer for the rear battery [say when you're cleaning the car], but I also try and let the car run every time I start it so it wakes up properly and thus goes to sleep properly too. I suggest start with a new battery and remember that each time you start it the alternator charges the front battery first [to put back the start charge] then the rear so it might need a good run to top both up. If you find yourself doing short journeys, you might like to invest in a charger. All the best.

 

[Phil Thomas]

I had similar probs and thought I had a drain on the battery in my 04 SL. MB swapped the battery but it also was poor so I got a third and now everything is OK. I would get a MB one from your nearest dealer; I bet they're not much more than Halfords and you know you're getting the right thing with a warranty. The consumers warning will come on when the battery falls below 11.5 volts. I bought a charger and every month I put it on low charge for a couple of hours just to keep the battery in tip top condition. I also switched off the locator lighting option which was causing a 'light sensor' warning on the dash at the same time. For the last 12 months it's been fine [fingers crossed]. Operating the roof and seats with the engine not running is a real killer for the rear battery [say when you're cleaning the car], but I also try and let the car run every time I start it so it wakes up properly and thus goes to sleep properly too. I suggest start with a new battery and remember that each time you start it the alternator charges the front battery first [to put back the start charge] then the rear so it might need a good run to top both up. If you find yourself doing short journeys, you might like to invest in a charger. All the best.

As I often leave my cars in SA for a few months, I usually either disconnect the battery (I don't have these pesky new fangled things with special batteries), or use the trickle chargers that can be left permanently on. They work well, and you don't need to disconnect the battery when using them as normal chargers. I would think that connecting them to the convenience battery would be beneficial.

I bought a larger charger of this type in Halfords, which goes into trickle mode when the battery is charged fully. It might even be possible to connect it across the main battery and keep both in order: they are both charged from the same source in normal use.

 

[Diesel Benz]

It might even be possible to connect it across the main battery and keep both in order: they are both charged from the same source in normal use.

The two batteries are not connected when the car is switched off. If the batteries were connected in parallel, it would not matter which battery the trickle charger was connected.

There is a DC/DC converter that the car can use to charge starter battery but there is a relay too that can be closed to run both batteries in parallel in some cases (but not when the car is completely sleeping).

With a single trickle charger on the starter battery one can be sure that the car always starts after it has been parked for a long time. But it would be good to avoid the rear battery too running flat (two trickle chargers would be the safest solution then).

 

[tromppost]

My 04 SL needed a new battery at about 4.5 years - exactly this fault, and so did my friend's 03 SL at 4 years - so you've done better than me or him ! (Neither of us do many long journeys, and cars not used that much, so a bit harder on the batteries)

Battery is in the boot, you need a 13mm long socket set to release the battery and a 10mm spanner to undo the battery terminals. Undo & remove the ground one first. Dont forget to connect the emergency-acid-overflow tube back up again. Re-connect & tighten the live first. Expect a spark when you connect the ground back up.

Most battery shops will fit this for you. Personally I always put a Mercedes battery back in again, because on a 4 year old car you can argue for a 20% discount on parts at many MB dealers, and it has a 2 year warranty on it

Richard

20% discount on parts!! What dealer do you use, GreenOaks or Beaconsfield?

 

[mr. shr]

Personally I always put a Mercedes battery back in again, because on a 4 year old car you can argue for a 20% discount on parts at many MB dealers, and it has a 2 year warranty on it

Richard

How do you manage to wangle 20%?
Is it because you're a business?
Most I've ever got is 10%

 

[richard]

Actually, thats my mistake. Its 20% on labour on 4 year old cars but only 10% on (many) parts at MB owned dealerships and Tony Purslow, and greenoaks also has a very good discount scheme now.

I do get a bit more sometimes on parts but sadly not 20% (and some parts the dealers have tiny margins on so theres less then). But then I buy serious amounts of parts for comandonline so that seems fair enough.

R

 

[richard]

Actually, thats my mistake. Its 20% on labour on 4 year old cars but only 10% on (many) parts at MB owned dealerships and Tony Purslow, and greenoaks also has a very good discount scheme now.

I do get a bit more sometimes on parts but sadly not 20% (and some parts the dealers have tiny margins on so theres less then). But then I buy serious amounts of parts for comandonline so that seems fair enough.

R

 

[blak500]

thanks for the advice guys, have booked in at merc epsom to have the battery replaced, they offered 15% discount on the parts and 30% on the labour so 111 on the battery and 47.50 on labour incl of VAT ... so hopefully thats sorted as I cant open the roof until i have driven the car for 15mins!! and the weather is brilliant at the mo!!!!

 

[recycled]

talking about batteries. My negative terminal has sheared into 2. Is this a whole new part and where can i get it.
Thanks
part no MB2025400231

 

[mr. shr]

Going by the part number you supplied, it's not too expensive from here.

 

[recycled]

Thank goodness for good neighbours.
One gave me a terminal,i cut and fitted in the Mb cable and presto, all sorted.