Battery Drain

[Mattymerc]

For some reason the battery is going flat if the car isn't touched for a couple of days
A mechanic friend has checked it out and tells me it is draining by about 1Amp per hour
I have checked online and it gives all sort of advice on how to check where this drain is
Normally it is suggested to remove fuses one by one with a Multi-meter between the negative terminal of the battery and the earth
The mechanic is telling me that Mercs only shut everything done after 30 minutes once the ignition is switched off, so removing the fuses one by one will be a long job

Any advise out there - Please

 

[Ted]

First of all, there is no such thing as 'one amp per hour' - it must be draining at one amp.

On the other hand, the other advice is good - by putting a multimeter (amps range) in line with the battery terminal and earth lead you will be able to measure the current flow and pull the fuses to find out what circuit is causing the drain.
While it may take half an hour to 'go to sleep', one amp is much more that the quiescent current of any modules, and you should see the current drain drop off pretty dramatically when you isolate the circuit.

I seem to remember that the leccy seat modules on these can cause a current drain - it may be worth starting your search there, or check the boot light isn't staying on (although this would only take half an amp)

Hope you get it sorted soon - looking for a battery drain is no fun in this sort of weather

 

[nb_racing]

As above, however disconnecting the fuses can be misleading. It will often be a control unit causing the drain so personnally I would start by disconnecting the power supply connector to each control unit one by one.

I think the car should shut down much sooner than 30 minutes. More like 2 or 3. I stand to be corrected on that.

 

[Mattymerc]

First of all, there is no such thing as 'one amp per hour' - it must be draining at one amp.

On the other hand, the other advice is good - by putting a multimeter (amps range) in line with the battery terminal and earth lead you will be able to measure the current flow and pull the fuses to find out what circuit is causing the drain.
While it may take half an hour to 'go to sleep', one amp is much more that the quiescent current of any modules, and you should see the current drain drop off pretty dramatically when you isolate the circuit.

I seem to remember that the leccy seat modules on these can cause a current drain - it may be worth starting your search there, or check the boot light isn't staying on (although this would only take half an amp)

Hope you get it sorted soon - looking for a battery drain is no fun in this sort of weather

Thanks
Been told it was the leccy seats


Sorted

 

[rorf]

Common drain on these cars- electric seat controls, built in Cell phone and CD player in the boot