Severe Battery Drain on 2004 W209 Convertible

[Dougaltop]

Hi Folks, here's the promised update. My local auto electrician traced the battery drain through fuse No 8 in the loading bay (boot). This feed is for the intruder siren/convenience locking. To find the actual 'fault' would be like looking for the proverbial needle in a haystack and cost mega bucks to fix. However, the drain is 100 milliamps or less and the solution I have found to overcome this was to invest in a £25 AA car charger solar panel with an EOBD connector. This produces up to 200 milliamps in ideal conditions. After standing for a week with the panel connected, the car fired up straight away. I am hoping this will continue over the winter. The alternator, by the way, is producing well over 14 volts. Hope all this helps.

 

[Dougaltop]

SOLAR PANEL TO OVERCOME BATTERY DRAIN

Hi Folks, here's the promised update. My local auto-electrician traced the battery drain through fuse No 8 in the loading bay (boot). This feeds the intruder siren/convenience locking circuits. To find the actual fault would be like looking for a needle in a haystack and would cost mega bucks to fix. However, the actual drain is just 100 milliamps or less. To overcome this I have invested £25 in a AA car charger solar panel with an EOBD connector. This has an output of up to 200 milliamps in ideal conditions. Having left the car for a week with the unit connected, it started without a problem. I know this is not actually resolving the root cause but at least the solar panel can be carried around and connected at anytime. The alternator, by the way, is producing well in excess of 14 volts. Hope all this helps.

 

[turbopete]

chances are the alarm siren has failed and needs replaced to cure the fault. IIRC they cost about £80 from what ive read.

 

[Dougaltop]

Hi TurboPete, forgive the ignorance but what is IIRC? Doug

 

[television]

Hi TurboPete, forgive the ignorance but what is IIRC? Doug

If I recall

 

[Dougaltop]

TurboPete, thanks.

 

[Dougaltop]

An update on the battery drain problem. The solar panel is only a temporary solution. Over the dull winter days it is not pumping out enough current to overcome the discharge rate. A second opinion on a leak to the intruder siren found disconnecting the siren (situated under the near side [UK] front wing didn't stop the discharge. Pulling all the fuses hasn't showed the problem up either and the discharge continues between 2amps and 300milliamps- so the hunt still continues. Fortunately, I have a friendly garage who is looking at the problem between more revenue earning jobs as I don't really need the car at the moment. More to follow...

 

[Westheath]

Hi TurboPete, forgive the ignorance but what is IIRC? Doug

If I recall

Or

If I Remember Correctly

Same meat different gravy.



Back to the OP's problem.....

Have you had a thorough test done on the charging and battery system ?












.

 

[Tooth Fairy]

Have you had a thorough test done on the charging and battery system ?

If there is a broken diode on the alternators regulator it will drain the battery.

 

[television]

If there is a broken diode on the alternators regulator it will drain the battery.

Yes a short circuit diode can cause a drain, but at the same time the charging would be poor.

 

[JenJen]

An update on the battery drain problem. The solar panel is only a temporary solution. Over the dull winter days it is not pumping out enough current to overcome the discharge rate. A second opinion on a leak to the intruder siren found disconnecting the siren (situated under the near side [UK] front wing didn't stop the discharge. Pulling all the fuses hasn't showed the problem up either and the discharge continues between 2amps and 300milliamps- so the hunt still continues. Fortunately, I have a friendly garage who is looking at the problem between more revenue earning jobs as I don't really need the car at the moment. More to follow...

 

[JenJen]

Hi i know its a while back but did you ever find the solution?

 

[paulaandp]

Well make me number 3. My new car (2004 clk) is beautiful but today has thrown all the same issues in the seed post for this thread.........sad thing is I've only owed the car 3 days. I really hope its just a low battery. Did anyone ever get a resolution to this?