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Discussion Starter · #1 ·
I am not certain how the Mercedes trickle charger should be hooked up to the battery of a 2008 S600. Any help would be appreciated. The car has two batteries: a starting battery in the engine compartment and a serving battery in the rear that keeps the electronics of the car running. I have been told that this serving battery can be 'reached' by attaching the trickle charger to the poles found adjacent to the starting battery. The + clip to the third from the left pole and the - clip to the far right pole.

Is this correct?

Thanks in advance.
 

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Are you planning to use two trickle chargers. Or are you counting on the starter battery maintaining power when electrical consumers are only (mainly) using the rear battery? The car can be started with a flat rear battery but should not with a flat front battery (diesel engines use the rear battery but only at extreme cold, should not help you even if it was a diesel :). I'm not sure about the Diesel with a flat front battery and normal temperature).

Anyway the wiring advice seems to be partially incorrect. There is only one 25 mm2 red cable from the trunk battery to the front pre-fuse box. I could not figure out which one it would be but I'm guessing on the far right side wire on your photo where the connector also has a tap, like for attaching a charger. This one is a live wire in my car at least! You could double-check and measure from your car but it isn't good to connect a charger to two live wires (the other one you mention is also live).

If you can find a connector pin name, it should be I1 at the pre-fuse box.
 

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Discussion Starter · #3 ·
Are you planning to use two trickle chargers. Or are you counting on the starter battery maintaining power when electrical consumers are only (mainly) using the rear battery? The car can be started with a flat rear battery but should not with a flat front battery (diesel engines use the rear battery but only at extreme cold, should not help you even if it was a diesel :). I'm not sure about the Diesel with a flat front battery and normal temperature).

Anyway the wiring advice seems to be partially incorrect. There is only one 25 mm2 red cable from the trunk battery to the front pre-fuse box. I could not figure out which one it would be but I'm guessing on the far right side wire on your photo where the connector also has a tap, like for attaching a charger. This one is a live wire in my car at least! You could double-check and measure from your car but it isn't good to connect a charger to two live wires (the other one you mention is also live).

If you can find a connector pin name, it should be I1 at the pre-fuse box.
I am going to use just one trickle charger....and it will be on the rear battery using the connectors to it that are located next to the front battery.

Unfortunately, the S 600 owner's manual...in its almost 1,000 pages...makes no reference to how a trickle charger should be attached.

I think I'll try to post my question on the S forum also. Maybe some of the owners of the new S models have tried to hibernate their machines.

Thanks for your help
 

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I think I'll try to post my question on the S forum also. Maybe some of the owners of the new S models have tried to hibernate their machines.
That's a good idea. I had a look at the connector assignments but the two you mention did not seem to have any indication, a bit odd, perhaps the letters where not visible (I took another photo with better focus on the markings that are visible, note that I have one more wire, that is because you have twice the number of cylinders :D, this is for the electric heater booster on diesel cars).

I also found a document showing a jump start clamp pin on the other wire you mention, instead of the rightmost one that your car has (and mine).

I guess MB assumes that charging the rear battery is not seen necessary for an owner and it is then not shown on the manual.

But I had a look at workshop documentation for battery charging and it clearly shows that the rightmost wire with the pin as shown on your photo should be used for charging the rear battery, the front battery ground pin can be used for charger minus.
 

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Discussion Starter · #5 ·
That's a good idea. I had a look at the connector assignments but the two you mention did not seem to have any indication, a bit odd, perhaps the letters where not visible (I took another photo with better focus on the markings that are visible, note that I have one more wire, that is because you have twice the number of cylinders :D, this is for the electric heater booster on diesel cars).

I also found a document showing a jump start clamp pin on the other wire you mention, instead of the rightmost one that your car has (and mine).

I guess MB assumes that charging the rear battery is not seen necessary for an owner and it is then not shown on the manual.

But I had a look at workshop documentation for battery charging and it clearly shows that the rightmost wire with the pin as shown on your photo should be used for charging the rear battery, the front battery ground pin can be used for charger minus.

Good, I'll follow the workshop documentation. Thanks for your help.
 

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Discussion Starter · #6 ·
Today I did a test of the MB trickle charger when it is attached to the secondary battery (not the starter battery) on the S600. Remember, this secondary battery is located in the rear of the car but it is not easily accessed from there....it is, however, easily accessed using the poles under the engine hood next to the starter battery. The red clip must be attached to the third from the left + (red wired) pole. The black clip must be attached to a bit of metal in the engine compartment....not to a negative wire or pole. It is only then that the two significant bulbs on the charger light up (one for "ready" the other for "charging").
 

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Zotye Auto 1.5T T600 2016
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Guys, you have just confused the hell outa me:D I have never used the trickle charger for the 600 but when we charge the batteries in the normal fashion we simply connect direct to the starter battery and the other battery gets its charge direct from the starter battery.

As these two are interlinked it does not really matter, however the starter battery is more accessable. Please dont try to use two chargers as this would end in dissaster.

The starter battery is the Master and the aux battery in the boot is the slave, if that helps, so keep the master charged and the slave will be fed:thumbsup:
 

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Guys, you have just confused the hell outa me:D I have never used the trickle charger for the 600 but when we charge the batteries in the normal fashion we simply connect direct to the starter battery and the other battery gets its charge direct from the starter battery.

As these two are interlinked it does not really matter, however the starter battery is more accessable. Please dont try to use two chargers as this would end in dissaster.

The starter battery is the Master and the aux battery in the boot is the slave, if that helps, so keep the master charged and the slave will be fed:thumbsup:
I understand that at a workshop or a used car shop it is best to charge the starter battery as that is needed to get the car running. The other battery would get charged only if the car is running, isn't it. Otherwise the starter battery would go flat too when the car is sleeping a long time.

I'm not sure about the best approach with a single trickle charger. If you connect it to the front battery, the rear one will go flat in 6 months for sure. I guess even that is not too bad in Florida but if the car was frozen, the battery would get broken. I'm not sure about AGM batteries, I assume neither those stand freezing when flat.

But when the car is switched off, I don't actually see a problem with two trickle chargers, one for each. These anyway are floating and would only charge the battery enough to compensate for the small load (on the rear battery specifically) and any internal current leak in the battery?
 

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Zotye Auto 1.5T T600 2016
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OOOOOOnnnnnnnOOOOO. slow down a bit. I have already pointed out that these two batteries are inter-linked and therefore a 12v charge to the rear and a 12v charge to the front 12 plus 12 equals 24v and you would fry something,

If you want to use two chargers then disconnect the front battery from the car first and charge it seperately.

The fact that the front battery is no longer on the car will not stop the rear battery from keeping its job going. Remember the front battery is for engine starting only.
 

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OOOOOOnnnnnnnOOOOO. slow down a bit. I have already pointed out that these two batteries are inter-linked and therefore a 12v charge to the rear and a 12v charge to the front 12 plus 12 equals 24v and you would fry something,

If you want to use two chargers then disconnect the front battery from the car first and charge it seperately.

The fact that the front battery is no longer on the car will not stop the rear battery from keeping its job going. Remember the front battery is for engine starting only.
I'm afraid you did not do the maths right. If you connect a 12 V floating charger in parallel to the front battery and a 12 V floating charger in parallel to the rear battery, both would see the same ground, cannot sum up to 24 V.

Even if the internal charging system was operating in the car, the additional current from the trickle charger would be a fraction of that the car is charging the rear one.

Anyway, I believe we both have made our views clear, I'll leave the rest for you and others to think about.
 

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Discussion Starter · #11 ·
My S600 was on a trickle charger for 10 months while we were at home in Bangkok. When we got back to Florida the car started up right away.

The trickle charger on the SL55AMG worked just as well.

Those trickle chargers are super.
 

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Discussion Starter · #12 ·
We are returning to Bangkok on Friday so I'll have to hook up the two trickle chargers to the two cars....as we will be gone for about eight months.
 
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