Battery loseing charge, idea,s?

[steve.o]

Hi
my k redg 250 d keeps loseing charge from battery ,
battery test o.k and so dose the alternator ,i have to put it on charge once a week, or use a jump from a charger,
it dosen,t loose all, their,s just not enough charge to turn engine over,anyone had this befor?any ideas?
thanks
steve.

 

[Diesel Benz]

Memory seat control unit? You would really have to diagnose which part is draining power, previous threads explain different options for this, like pulling fuses while monitoring the current consumption.

 

[m7m]

Draining current can be measured by placing an ameter between the negative terminal of the battery and earth.
Note that even though the current will be small, the ameter has to be capable of handling higher current, as there may be a small surge when first connected. This could blow the fuse of the ameter (it happened with my multimeter).

 

[manalishi]

I have W124 battery woes at the moment (another thread). Something that may help was pointed out to me by a forumite on A N Other MB forum. Add a simple battery isolator, like this one: Battery Isolator Switch Universal 6v 12v 24v on eBay (end time 05-Jul-10 14:43:24 BST)

When you unscrew the knob the battery is completely isolated = no current drain at all whatever the cause.

Of course, the underlying cause should be investigated anyway, and this widget helps there, too. Because you can measure the current draw simply by unscrewing the knob and then using the ammeter function of your DMM from one side of the terminal to the other (as mentioned above).

On my car, I need three hands though! One for each probe and another to blip the remote to quickly turn off the alarm that always sounds when the battery is reconnected.

 

[steve.o]

HI
took car to local ato shop, battery tested running and
not,no problem,
alternator tested fine,
i thought alternatoer would be tested with lights on ect to see if their a drain
from certain area,s ?
steve.