dirtyguido

Hey guys,

So I have a recently purchased 04 R230.

When I first bought the car at the dealer auction it was giving me an electric consumers offline message. About 20 miles in it went away and everything was fine. However, until the weather gets to convertible season here, It will be an occasional driver. And I fear that the consumer battery will just be run down again.

I have a trickle charger / maintainer hardwired to the battery with a quick disconnect on my jaguar convertible and it works great. I have another trickle charger / maintainer I'd like to use with my r230 but the dual battery setup is kind of confusing me. My trickle charger comes with 3 options, hardwired lugs. Alligator clips, or cig lighter plug.

What's the best way to keep the car connected to the charger? Should I just plug into the cig lighter? (or would that require the key to be on?).

Any help is appreciated.

Thanks in advance,

George

funymuny

If your cigarette plug has no power when engine is off (as mine was/is) I do not believe you can put power back to the system through the cigarette plug. Besides that, the electronics are so pervasive I would not do that anyway simply out of an abundance of caution. When I use a maintainer on my SL I go directly to the battery. Clips or mounted...matter of preference. My 10 Corvette had lighter power with engine off and I did use the cigarette lighter for battery maintainer without issue. Mark

carguyshu

connect it to the battery in the trunk and not the battery under the hood. the hood battery is used only for starting. the trunk battery does all the consumer stuff and when it gets fully charged it will open a circuit to also charge the front one. it does not work the other way however

F1BHP

Carguyshu is correct however if your SL has a cigarette lighter outlet in the trunk as mine does it can be used to trickle charge the consumer battery in the trunk.

The best option would always be to fit a quick disconnect to the battery direct.

kbob999

If the car was dormant for an extended time, this trickle charge may work.
However, in many cases it will require the trunk battery to be replaced.
I had to replace mine to clear this message from popping up, and prevent getting calls from my wife about not being able to drop the top.
This battery is replaced frequently in R230's. Your mileage may vary...

dirtyguido

The car prob sat dormant or with very limited use for a couple months prior to my purchasing it.

After a drive it sat dormant for about two weeks before I got the electrical consumers offline msg again. I hooked up a trickle charger / maintainer and within 10 mins the message was gone (but I have to reset my settings on my aftermarket radio etc)... So I'm just going to keep it on a charger now....

Until the weather breaks and it goes into semi daily driving duty. Then we shall see how things go. Worse case I pop a battery into it.

Take care,

George

F1BHP

If the warning comes up after 2 weeks that is completely normal, if it was 2 days then you would need to look at changing the battery.

The AGM battery in the trunk should give you 5-7 years without trouble as long as it has been maintained.

Frederick NL

It is quite simple to wire the 12 volt 'cigarette lighter' socket in the trunk directly to the rear battery and use it for trickle charging. In standard mode it is disconnected with the ignition off. Of course, I added a fuse in the wire. Going the neat way, I orderded a new wire with the proper connector at MB (cost: next to nothing) and left the original wire idling behind the side panel.

With my small Ctek trickle charger I measured a 55 mAmp draw (measured over mains draw), after having used some accessories with the engine of. In Holland mains supply rates 230 Volts, so you're looking at a 15 watt current (from the grid), more than I would have expected even taking a bit of loss between prim and sec in the charger into account.

Will wait for green LED on the CTek to come on, and measure again.

TheSaint

I hooked up a Ctek MSX 5.0 trickle charger to the rear battery. Used the charger this winter when the car was standing unused
The trickle charger came with wires with eyelets so you can screw on the wires like i did.

The charger also came with a wire set with clamps which i use on other batteries.
I have seen original Mercedes trickle chargers and i am pretty sure that they are CTEK charhgers that Mercedes have put their logo on.

As other member here have said already connect the trickle charger to the battery in the trunk

Frederick NL

Draw with green led on: 10mA.

jnice72

I have used this CTEK charger, hooked up with the permanent quick disconnect terminals as in TheSaint's post, for years. I hook it up whenever I won't drive the car for a week or more. They are inexpensive. The MB one is the exact same thing that costs about double because it has Mercedes wrap/logo on it.

TheSaint

And to add to what jnice72 just said i read on Cteks homepage that Mercedes is one of the customers of the Ctek chargers and get the charger with the Mercedes text and logo. You will fin it under clients brand on ctek`s homepage
Here is a link: https://www.ctek.com/se