battery change procedure

[Geoff W]

Hi all.
Can someone tell me the correct procedure for changing the battery on my 97 C 180, I understand i could do damage if the correct procedure is not followed, so fore warned is fore armed, as they say.
All help appreciated.
Regards Geoff.

 

[Andy Wr]

When I changed mine on my old C180 it was a case of disconnecting the negative terminal first, then the positive and fitting is reversal of removal. Once fitted you have to reprogramme all of the electric windows, it explains how to do so in the owners booklet, takes minutes to do and is dead simple.

 

[C220GJS]

First make sure you have the radio code as this will be lost when you disconnect the battery, then as Andy Wr says.

 

[television]

there is a correct way on this car,will look it up in the morning.

Malcolm

 

[bigasotonuk]

Are we talking a pre or post face lift?
Is there a correct procedure for changing the battery on my c230k pre face lift?(besides the order in which you disconnect the battery terminals).
I,ve disconnected the battery several times and all that happens is my engine won,t idle until its been driven for approx 10 minutes or so.

 

[Wezzel]

Presumably it is possible to use jump leads from the terminals under the bonnet to another vehicle before changing the battery.

This way it will not disturb things.

I once changed the battery on a Peugeot without loosing the radio code ('cos I didn't know it) by taping jump leads onto the battery terminals (to stop them falling off) and running them to the wife's car before disconnecting the old battery and reconnecting the new one.

 

[television]

For the 202 as from 12/94 you can get a charge retention kit to energize the ciger lighter charge point in the boot.

With out that it is better to turn the headlamps on while changing the battery to obsorb any spikes that could be damaging.

This program i have is useful but a pig to use,I see things one day,try and find it the next,and no way. I can see why the dealeres do not like it and use the EPC version.

Malcolm

 

[puter]

Wezzel has it dead right. Furthermore any battery shop worth its salt usually keeps a small motor bike battery to bridge whilst changing batteries. The impedance of a lead acid battery is so low, that any sparking in my experience is not likely to be a problem.

 

[television]

Wezzel has it dead right. Furthermore any battery shop worth its salt usually keeps a small motor bike battery to bridge whilst changing batteries. The impedance of a lead acid battery is so low, that any sparking in my experience is not likely to be a problem.

Not impedence sir, resistance.. Impendence is current offered to a AC circuit.

One of the 12v dry cells of the burglar alarm sort would do fine as a back up, only needs two long thin leads with crocodle clips.


Malcolm

 

[John Kerr]

When I first bought my W203 220 CDI,the fuel gauge was reading three quarter full all the time.Reading up the problem on WIS it suggested disconnecting the battery for 15min. On reconnecting the earth it gave quite a spark and a lot of things stopped working,it turned out the rear Sam unit had blown at a cost of £400.Why would this happen when nothing was switched on.Malcom suggested turning the headlights on,is this the answer.

 

[television]

When I first bought my W203 220 CDI,the fuel gauge was reading three quarter full all the time.Reading up the problem on WIS it suggested disconnecting the battery for 15min. On reconnecting the earth it gave quite a spark and a lot of things stopped working,it turned out the rear Sam unit had blown at a cost of £400.Why would this happen when nothing was switched on.Malcom suggested turning the headlights on,is this the answer.

Hello John, this type of thread is always a worry as to what to do, and yes i have heard of the SAM units going down when changing the battery.

Its also important to make sure that the doors are closed so the circuits are not active.
Having one of the burglar alarm dry batteries would be the perfect solution and by using long thin cables to join to the battery terminals to eliminate the risk of knocking them off when changing.
The MB instrutions fall rather flat, they say turn on the heated seats and rear window to obsorb the spikes, sadly these circuits are only used with the ignition turned on, this would make things even worse.

Malcolm

 

[puter]

For information regarding battery impedance goto Google and type battery impedance.

 

[television]

For information regarding battery impedance goto Google and type battery impedance.

Sorry to be diffucult on this, yes after a search the headline maybe impedence , but every article refers to resistance.

You cant have impedence in a battery.

Refference Collins Dictionary.

Measure of the opposion to the flow of alternating current equal to the square root of the sum of the squares of the resistance and the reactance expressed in ohm's

In practicle terms, things like loudspeakers and microphones are measured in impedence, they are components consisting of a coil and a magnet where the movement of the coil in relation to the magnet produces an alternating voltage and the resistance of that coil is expressed in impedence.

Just because it is on the web,does not make it correct. It was all drummed into me in 1948 and nothing has changed sinse then

 

[Blobcat]

Its also important to make sure that the doors are closed so the circuits are not active.

Not very easy to do when your battery is under the back seat.

 

[television]

Not very easy to do when your battery is under the back seat.

Yes it is easy,just remove the squab,get in car,close the doors and disconect one lead from battery,open the door,get out,remove other lead and lift out battery. Lift new battery in,join up one lead,get in close door and join up second lead, refit seat squab.

The reason that the doors should be closed is that the action of opening one, this tells the SAM's that the car is going to be driven and it all comes to life !!!!!!!! thats the last thing that you want when changing the battery.

Malcolm

 

[Blobcat]

Yes it is easy,just remove the squab,get in car,close the doors and disconect one lead from battery,open the door,get out,remove other lead and lift out battery. Lift new battery in,join up one lead,get in close door and join up second lead, refit seat squab.

The reason that the doors should be closed is that the action of opening one, this tells the SAM's that the car is going to be driven and it all comes to life !!!!!!!! thats the last thing that you want when changing the battery.

Malcolm

If you open the door to remove the squab then the SAM will be woken up. As most people start the car with the door shut the SAM would not just shut down when you close the door. So getting in the back and closing the door would not be enough.
How long does it take for the SAM to shut down? Do you get in the back close the door, wait for ?? minutes then disconnect the battery?
Or do you get in the back switch off the interior motion sensors then lock the car and wait. Then unlock the car but don't open a door then disconnect the battery??
Does the SAM wake up when you unlock the car?

 

[television]

This info was really aimed at the C CLass where the problem and blown SAM's accure. I will not be taken to task on this subject, I pass on every known piece of info that I can find
The EClass is fairly straight forward in changing the battery.

Re the SAM's The front doors do activate the SAM's,I do not know if the rear doors do,but I doubt it as it is not possible to drive the car from the rear seat.

I sat in and took part in a lecture 2 months back on this subject, it is a long and involved subject and I read every available update I can to pass the info on. Sadly these days Joes garage can do a lot of harm thinking that you can still do things as you did 10 years ago, you cant. There are flaws and incorrect statements in the MB instructions, heaven help us all.

plugging a back up into the ciger lighter will save the radio code, but not the rest as the cigar lighter is only ative in key 1 and 2. a dedicated charger socket will save the day and a kit with full instructions is available from MB for the C Class and most others.

malcolm

Malcolm