SLcharger

Light is off after about 10 min. 12 volt socket in boot, is a convinience outlet, if you would like to cary a 12 volt powered coolbox, ( cool beer, nice thing though ) need an extra light when fixing a flat at night, etc. Beware of the coolbox, only have it connected while the engine is running, those devices draw a lot of power, and can empty a battary within a few hours. Most power efficient coolboxes are those fitted with kompressor. They can be left connected to the car for several hours, while you chase the girls at the beach

uk1

Thanks - wondered about that. What is the plug/socket type called? It looked like a sort of din socket.


Thanks

Jeff

uk1

Just a postscript to this thread - I appreciated the suggestions and help - and thought others might be interested in the outcome.

My expectation was that my battery was knackered. It's an 03 SL500 with only 8k miles and has long periods unused in the garage whilst we're abroad on extended trips. The "electrics offline" message was always coming on after around 5 days, and also lately the alarm started to go off after around 10 days. My conclusion was that the battery was probably now knackered as many other owners posting have replaced it having experienced similar problems.

Having left the battery connected to the charger, I now wonder whether the charger has "repaired" or "reconditioned" the battery - which I instinctively believe to be impossible - but does appear to have happened and whether these are a bit more forgiving than cheaper batteries. The charger was left on the battery for a couple of weeks and we had a run of 150 miles and then I left the car in a garage for over two weeks that didn't have a power point - hence no charger - and after that period the car started with all electrics online. Previously the run alone without the charger would have had the "electrics offline" message after around 5 days or so. My thought is, do these particular batteries "repair" and perhaps we're replacing them prematurely?

Thought others might be interested.

Jeff

mikeblah

Well even though my experience has led me to believe that you cannot recondition a battery once it is going bad, your experiment seems to prove that theory wrong.

My battery is showing that warning after about 24 hours of non use at this point. Even if it did seem to be improving with charging, etc. I think I would just go ahead and replace it. Nothing worse than not replacing it when you know it's going bad and then having it cause some major inconvenience soon after.

Although, I guess the car wills still start, just not heat up the seats as soon as you get in... Oh... and of course the alarm going off at 4 in the morning would be enough to warrant a swap.

I'll be going to the dealer with my short list of issues in the next week or two. This battery being one of them. We'll see what happens...

uk1

Mike,

My view about replacement was identical to yours. Except that whereas it seemed to me that it would be essential to replace the primary battery you use to start the car straight away because you don't want to be caught out, my view was that this just wasn't quite as urgent for the service battery. After all, the car would always start, and electrics would come on-line withn a few minutes. And then the new charger seemed to keep the service battery ticking over. So I had it in mind to simply wait for the next service. Then I noticed that the battery seemed to be "repaired".

Hopefully one of the experts in the battery field can comment about whether such a thing as a repair is possible. If so it may relieve many owners of having to keep buying these every couple of years.


Jeff

SLcharger

What you expirienced is reconditioning of a sulfated battery. Batteries that are exposed to the conditions descibed in this thread, tend to sulfate the lead plates in the battery. This sulfate acts as an isolator, and wont let the current pass. When connecting a 3 or 4 step charger to the battery it will first charge the battery, and then trigle charge. The tricle charging involves current bursts, whitch tend to, slowly, knock off the sulfate from the plates. Time is a factor here. Therefore the longer the charger is connected to the battery, the better it gets, until it has regained 100% capacity. This method can also be used retrieving scrap batteries, to new life.

I hope this answers your question.

uk1

Thanks SLCharger,

To double check - when you say it reaches 100% capacity - does this effectively mean that in effect the battery is as good as new?

Jeff

slsteve

My 03 sl500 lasts about 5 days before losing heated seats etc,

But there back on after about 5 minutes of driving so dont really cause me a problem.

As for the alarm, i always leave the car unlocked, and the alarm never goes off

uk1

SLSteve,

The only problem is that you need to consider that if your car was stolen some insurers might think that as the garage is a relatively easy door to crack and therefore vulnerable, that as you have a car with first class security (with Tracker I assume as well) then by defeating the security you hadn't taken "reasonable care" by leaving the car unlocked. With many insurers you would be uninsured but not know this until you make a claim.

I wouldn't take that risk.

Jeff

ps in the UK an insurer rejected a claim and the ombudsman supported the insurer:

"The insurer rejected the claim. It explained that the policy excluded liability for thefts if ‘the car is left unattended or unoccupied and the doors…. are not locked’.

complaint rejected
We were satisfied that the car was both unattended and unoccupied at the time of the theft. We accepted that the household insurer was satisfied that the policyholder had behaved reasonably, but that was not the motor insurer’s reason for declining liability and was therefore not relevant in this situation. "

Vik888

Why would you tell them that you left the car unlocked, even if it was stolen with the doors unlocked? How would they know any better?

What a dumb thing to admit to -- insurance companies will do anything to not pay a claim.

Were they going to get testimony from the thief?

uk1

Not locking your car door in the garage is an unneccessary risk and certainly making a false statement to an insurer and the police as you suggest is unwise and fraudulent unless of course you are certain you won't be caught out. It's also avoidable. Simply lock the car and attatch a charger to the battery.

In the UK this class of car is always fitted with "Tracker" and with the top end unit it can detect when the car has been "stolen". You'd need to explain to the insurers how Tracker didn't detect that the car had been forced and taken.

http://www.tracker.co.uk/home.php?SVR/Works/horizon

Jeff

SLcharger

Yes

swag72

Sorry to sound really stupid, but I have a really dumb question. I have just bought a 2004 SL350. While all this battery lark is fascinating, am I right in thinking that after my 3 week holiday I will come back and my car will be as flat as a pancake?

I have never experienced this in my previous SLK or fords I owned previously. Are you telling me I have spent all this money but will have to jump start this bloody thing and look REALLY uncool?!!

HELP!! Put my mind at rest! I can't have a trickle thingie as my car does not fit in my garage!!!

slsteve

No u r wrong the car will start perfectly, u just wont be able to warm your a*se for about 5 minutes. lol

This thread is pointless in my opinion

Ps why the f*ck would i say i left the car unlocked to the insurers lol the tracker will still be working, and lets all face the truth here, if some low life wants your car, he is going to smash the front door of your house to get the keys, he wont be able to steal the car without them. so who cares if its unlocked in the garage.

By time my dog would have ate him :p

gotglasses

This is an old thread, but I wanted to add my recent experience with my 04 R230.

My concern is the ABC system. How long can an SL be expected to hold ride height and not settle lower?

Bought this car on Ebay for a fair price and it is immaculate. The Top worked and it had a recent Service. I did not have a local pro check the car out since in the past I have found them to know less about "exotic" cars than I do. Your mileage may vary.

The 2003 500SL was the first factory car to come with two batteries! This was necessitated by the electrical loads of the ABC suspension system, the folding hardtop and the essential monitoring systems.

Surprise - the car also has no springs holding it up! The ABC takes their place, just like an old Citroen.

Whenever the car sits parked for several days I noticed that the height of the car would vary. The ABC height sensors would turn the pump on and raise the car! If this happens a few times it can deplete the battery voltage and the service goes "offline" to save the battery. My fear was that I have an imminent failure of the ABC system which would cost thousands of dollars to repair. That may still be the case if the car loses ground clearance while driving.

The system does tailor the ride height while driving and seems to be functioning perfectly. It does take a few days for the car to get noticeably lower. This is no worse than what Citroen owners have experienced since the 1950's.

So - when do I need to worry?

blueSL

My SL55 is quite old now and will lose height when not being driven. If I used it everyday, it would not be a problem but over winter, the height on one side collapses but recovers as soon as I start the engine. There's a leak of pressure somewhere though fortunately not of fluid.

The dealer doesn't know where to start so I am living with it. It's important to know though that the ABC system is both complex and extremely expensive to maintain. The suspension struts are something like $1500 a corner to replace, maybe more because of the extensive dismantling required.

Rudeney

I believe you have a few misconceptions.

Although the dual-battery system was necessary for the extra electrical consumers in the car, it's not because of the ABC system. It uses very little battery power as the only electrical needs are for its computer module and electrically-activated control valves. The hydraulic pressure is generated by a belt-driven pump. And there are springs integrated into the shock/strut units. They are just not strong enough to support the vehicle - that requires hydraulic pressure.

One of the key components of the car that needs extra battery power is SBC. This braking system uses electrical power instead of engine vacuum to not only assist the brakes, but to actually engage them. In a way, it's a "brake by wire" system.

This is a very good resource on the ABC system:

http://mercedes-abc-drive-carefully.blogspot.com

Based on your symptoms, unless you have a leak (and I assume you do don't as you did not mention that), then it sounds like a bad/dirty valve block (covered in that document).

blueSL

The real reason two batteries were required is not because of the power usage when the car is running - all of that is provided by the alternator. It's due instead to the static current drain when the car is not in use which means that a single battery would go flat and the car would then not start.

The smaller battery in the engine compartment is effectively isolated when the car is not is use, has no static drain and will allow the car to be started even if the larger battery is completely flat. This should not be allowed to happen though as the battery will become damaged and trickle-charging the battery will keep it fresh.

Modern electronics uses much less power when shutdown and is not an issue.